return NULL;
}
- if (getcwd (tmpbuf, LOCAL_PATH_MAX) == NULL)
+ if (getcwd (tmpbuf, PATH_MAX) == NULL)
{
/* We use 1024 here since it should really be enough and because
- this is a save value. */
+ this is a safe value. */
__strerror_r (errno, buf, 1024);
return NULL;
}
# Library General Public License for more details.
# You should have received a copy of the GNU Library General Public
-# License along with the GNU C Library; see the file COPYING.LIB. If
-# not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-# Cambridge, MA 02139, USA.
+# License along with the GNU C Library; see the file COPYING.LIB. If not,
+# write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
#
# Specific makefile for libio.
routines := \
filedoalloc iofclose iofdopen iofflush iofgetpos iofgets iofopen \
iofopncook iofprintf iofputs iofread iofsetpos ioftell \
- iofwrite iogetdelim iogetline iogets iopadn iopopen ioprims ioputs \
+ iofwrite iogetdelim iogetline iogets iopadn iopopen ioputs \
ioseekoff ioseekpos iosetbuffer iosetvbuf iosprintf ioungetc \
iovsprintf iovsscanf \
\
include ../Makeconfig
+CPPFLAGS-.o += -DIO_DEBUG
+
ifneq (,$(filter %REENTRANT, $(defines)))
routines += clearerr_u feof_u ferror_u fputc_u getc_u getchar_u \
iofflush_u putc_u putchar_u peekc
endif
aux := \
- cleanup fileops genops stdfiles stdio strops
+ fileops genops stdfiles stdio strops
distribute := iolibio.h libioP.h strfile.h Banner
register char *p;
struct stat st;
+#ifndef _LIBC
/* If _IO_cleanup_registration_needed is non-zero, we should call the
function it points to. This is to make sure _IO_cleanup gets called
on exit. We call it from _IO_file_doallocate, since that is likely
to get called by any program that does buffered I/O. */
if (_IO_cleanup_registration_needed)
(*_IO_cleanup_registration_needed)();
+#endif
if (fp->_fileno < 0 || _IO_SYSSTAT (fp, &st) < 0)
{
The position in the buffer that corresponds to the position
in external file system is normally _IO_read_end, except in putback
mode, when it is _IO_save_end.
- when it is _IO_save_end.
If the field _fb._offset is >= 0, it gives the offset in
the file as a whole corresponding to eGptr(). (?)
_IO_mask_flags(fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
if (read_write & _IO_IS_APPENDING)
if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT)
- == _IO_pos_BAD)
+ == _IO_pos_BAD && errno != ESPIPE)
return NULL;
_IO_link_in(fp);
return fp;
fp->_fileno = fd;
fp->_flags &= ~(_IO_NO_READS+_IO_NO_WRITES);
fp->_flags |= _IO_DELETE_DONT_CLOSE;
+ /* Get the current position of the file. */
+ /* We have to do that since that may be junk. */
fp->_offset = _IO_pos_BAD;
+ if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_cur, _IOS_INPUT|_IOS_OUTPUT)
+ == _IO_pos_BAD && errno != ESPIPE)
+ return NULL;
return fp;
}
#ifdef weak_alias
weak_alias (_IO_cleanup, _cleanup)
#endif
+
+#ifdef text_set_element
+text_set_element(__libc_atexit, _cleanup);
+#endif
#ifdef __cplusplus
}
#endif
+
+#define _IO_open __open
+#define _IO_close __close
+#define _IO_fork __fork
+#define _IO_fcntl __fcntl
+#define _IO__exit _exit
+#define _IO_read __read
+#define _IO_write __write
+#define _IO_lseek __lseek
+#define _IO_getdtablesize __getdtablesize
+#define _IO_pipe __pipe
+#define _IO_dup2 __dup2
+#define _IO_execl execl
+#define _IO_waitpid __waitpid
+#define _IO_stat __stat
+#define _IO_getpid __getpid
+#define _IO_geteuid __geteuid
+#define _IO_getegid __getegid
+#define _IO_fstat __fstat
proc_file_chain = proc_file_chain->next;
}
- _IO_execl("/bin/sh", "sh", "-c", command, NULL);
+ _IO_execl("/bin/sh", "sh", "-c", command, (char *) 0);
_IO__exit(127);
}
_IO_close(child_end);
int ret;
#ifdef _IO_MTSAFE_IO
- sf._f._lock = &lock;
+ sf._sbf._f._lock = &lock;
#endif
_IO_init ((_IO_FILE *) &sf, 0);
_IO_JUMPS ((_IO_FILE *) &sf) = &_IO_str_jumps;
_IO_strfile sf;
#ifdef _IO_MTSAFE_IO
_IO_lock_t lock;
- sf._f._lock = &lock;
+ sf._sbf._f._lock = &lock;
#endif
_IO_init((_IO_FILE*)&sf, 0);
_IO_JUMPS((_IO_FILE*)&sf) = &_IO_str_jumps;
#endif
#ifndef __P
+#if _G_HAVE_SYS_CDEFS
+#include <sys/cdefs.h>
+#else
#ifdef __STDC__
#define __P(protos) protos
#else
#define __P(protos) ()
#endif
+#endif
#endif /*!__P*/
/* For backward compatibility */
#define EOF (-1)
#endif
#ifndef NULL
-#if !defined(__cplusplus) || defined(__GNUC__)
+#ifdef __GNUG__
+#define NULL (__null)
+#else
+#if !defined(__cplusplus)
#define NULL ((void*)0)
#else
#define NULL (0)
#endif
#endif
+#endif
#define _IOS_INPUT 1
#define _IOS_OUTPUT 2
#define _IO_file_flags _flags
/* The following pointers correspond to the C++ streambuf protocol. */
+ /* Note: Tk uses the _IO_read_ptr and _IO_read_end fields directly. */
char* _IO_read_ptr; /* Current read pointer */
char* _IO_read_end; /* End of get area. */
char* _IO_read_base; /* Start of putback+get area. */
struct _IO_FILE *_chain;
-#if !_IO_UNIFIED_JUMPTABLES
- struct _IO_jump_t *_jumps; /* Jump table */
-#endif
-
int _fileno;
int _blksize;
_IO_off_t _offset;
#define _IO_seek_cur 1
#define _IO_seek_end 2
-typedef int (*_IO_overflow_t) __P((_IO_FILE*, int));
-typedef int (*_IO_underflow_t) __P((_IO_FILE*));
-typedef _IO_size_t (*_IO_xsputn_t) __P((_IO_FILE*,const void*,_IO_size_t));
-typedef _IO_size_t (*_IO_xsgetn_t) __P((_IO_FILE*, void*, _IO_size_t));
-typedef _IO_ssize_t (*_IO_read_t) __P((_IO_FILE*, void*, _IO_ssize_t));
-typedef _IO_ssize_t (*_IO_write_t) __P((_IO_FILE*,const void*,_IO_ssize_t));
-typedef int (*_IO_stat_t) __P((_IO_FILE*, void*));
-typedef _IO_fpos_t (*_IO_seek_t) __P((_IO_FILE*, _IO_off_t, int));
-typedef int (*_IO_doallocate_t) __P((_IO_FILE*));
-typedef int (*_IO_pbackfail_t) __P((_IO_FILE*, int));
-typedef _IO_FILE* (*_IO_setbuf_t) __P((_IO_FILE*, char *, _IO_ssize_t));
-typedef int (*_IO_sync_t) __P((_IO_FILE*));
-typedef void (*_IO_finish_t) __P((_IO_FILE*)); /* finalize */
-typedef int (*_IO_close_t) __P((_IO_FILE*)); /* finalize */
-typedef _IO_fpos_t (*_IO_seekoff_t) __P((_IO_FILE*, _IO_off_t, int, int));
-
-/* The _IO_seek_cur and _IO_seek_end options are not allowed. */
-typedef _IO_fpos_t (*_IO_seekpos_t) __P((_IO_FILE*, _IO_fpos_t, int));
+/* THE JUMPTABLE FUNCTIONS.
+
+ * The _IO_FILE type is used to implement the FILE type in GNU libc,
+ * as well as the streambuf class in GNU iostreams for C++.
+ * These are all the same, just used differently.
+ * An _IO_FILE (or FILE) object is allows followed by a pointer to
+ * a jump table (of pointers to functions). The pointer is accessed
+ * with the _IO_JUMPS macro. The jump table has a eccentric format,
+ * so as to be compatible with the layout of a C++ virtual function table.
+ * (as implemented by g++). When a pointer to a steambuf object is
+ * coerced to an (_IO_FILE*), then _IO_JUMPS on the result just
+ * happens to point to the virtual function table of the streambuf.
+ * Thus the _IO_JUMPS function table used for C stdio/libio does
+ * double duty as the virtual functiuon table for C++ streambuf.
+ *
+ * The entries in the _IO_JUMPS function table (and hence also the
+ * virtual functions of a streambuf) are described below.
+ * The first parameter of each function entry is the _IO_FILE/streambuf
+ * object being acted on (i.e. the 'this' parameter).
+ */
-#if !_IO_UNIFIED_JUMPTABLES
-#define _IO_JUMPS(THIS) (THIS)->_jumps
-#else
#define _IO_JUMPS(THIS) ((struct _IO_FILE_plus*)(THIS))->vtable
-#endif
-
-#if !_IO_UNIFIED_JUMPTABLES
+#ifdef _G_USING_THUNKS
#define JUMP_FIELD(TYPE, NAME) TYPE NAME
#define JUMP0(FUNC, THIS) _IO_JUMPS(THIS)->FUNC(THIS)
#define JUMP1(FUNC, THIS, X1) _IO_JUMPS(THIS)->FUNC(THIS, X1)
#define JUMP2(FUNC, THIS, X1, X2) _IO_JUMPS(THIS)->FUNC(THIS, X1, X2)
-#define JUMP3(FUNC, THIS, X1, X2, X3) _IO_JUMPS(THIS)->FUNC(THIS, X1, X2, X3)
+#define JUMP3(FUNC, THIS, X1,X2,X3) _IO_JUMPS(THIS)->FUNC(THIS, X1,X2, X3)
#define JUMP_INIT(NAME, VALUE) VALUE
+#define JUMP_INIT_DUMMY JUMP_INIT(dummy, 0), JUMP_INIT(dummy2, 0)
#else
+/* These macros will change when we re-implement vtables to use "thunks"! */
#define JUMP_FIELD(TYPE, NAME) struct { short delta1, delta2; TYPE pfn; } NAME
#define JUMP0(FUNC, THIS) _IO_JUMPS(THIS)->FUNC.pfn(THIS)
#define JUMP1(FUNC, THIS, X1) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1)
#define JUMP2(FUNC, THIS, X1, X2) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1, X2)
#define JUMP3(FUNC, THIS, X1,X2,X3) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1,X2, X3)
#define JUMP_INIT(NAME, VALUE) {0, 0, VALUE}
-#endif
#define JUMP_INIT_DUMMY JUMP_INIT(dummy, 0)
+#endif
+/* The 'finish' function does any final cleaning up of an _IO_FILE object.
+ It does not delete (free) it, but does everything else to finalize it/
+ It matches the streambuf::~streambuf virtual destructor. */
+typedef void (*_IO_finish_t) __P((_IO_FILE*)); /* finalize */
#define _IO_FINISH(FP) JUMP0(__finish, FP)
+
+/* The 'overflow' hook flushes the buffer.
+ The second argument is a character, or EOF.
+ It matches the streambuf::overflow virtual function. */
+typedef int (*_IO_overflow_t) __P((_IO_FILE*, int));
#define _IO_OVERFLOW(FP, CH) JUMP1(__overflow, FP, CH)
+
+/* The 'underflow' hook tries to fills the get buffer.
+ It returns the next character (as an unsigned char) or EOF. The next
+ character remains in the get buffer, and the get postion is not changed.
+ It matches the streambuf::underflow virtual function. */
+typedef int (*_IO_underflow_t) __P((_IO_FILE*));
#define _IO_UNDERFLOW(FP) JUMP0(__underflow, FP)
+
+/* The 'uflow' hook returns the next character in the input stream
+ (cast to unsigned char), and increments the read position;
+ EOF is returned on failure.
+ It matches the streambuf::uflow virtual function, which is not in the
+ cfront implementation, but was added to C++ by the ANSI/ISO committee. */
#define _IO_UFLOW(FP) JUMP0(__uflow, FP)
+
+/* The 'pbackfail' hook handles backing up.
+ It matches the streambuf::pbackfail virtual function. */
+typedef int (*_IO_pbackfail_t) __P((_IO_FILE*, int));
#define _IO_PBACKFAIL(FP, CH) JUMP1(__pbackfail, FP, CH)
+
+/* The 'xsputn' hook writes upto N characters from buffer DATA.
+ Returns the number of character actually written.
+ It matches the streambuf::xsputn virtual function. */
+typedef _IO_size_t (*_IO_xsputn_t)
+ __P((_IO_FILE *FP, const void *DATA, _IO_size_t N));
#define _IO_XSPUTN(FP, DATA, N) JUMP2(__xsputn, FP, DATA, N)
+
+/* The 'xsgetn' hook reads upto N characters into buffer DATA.
+ Returns the number of character actually read.
+ It matches the streambuf::xsgetn virtual function. */
+typedef _IO_size_t (*_IO_xsgetn_t) __P((_IO_FILE*FP, void*DATA, _IO_size_t N));
#define _IO_XSGETN(FP, DATA, N) JUMP2(__xsgetn, FP, DATA, N)
+
+/* The 'seekoff' hook moves the stream position to a new position
+ relative to the start of the file (if DIR==0), the current position
+ (MODE==1), or the end of the file (MODE==2).
+ It matches the streambuf::seekoff virtual function.
+ It is also used for the ANSI fseek function. */
+typedef _IO_fpos_t (*_IO_seekoff_t)
+ __P((_IO_FILE* FP, _IO_off_t OFF, int DIR, int MODE));
#define _IO_SEEKOFF(FP, OFF, DIR, MODE) JUMP3(__seekoff, FP, OFF, DIR, MODE)
+
+/* The 'seekpos' hook also moves the stream position,
+ but to an absolute position given by a fpos_t (seekpos).
+ It matches the streambuf::seekpos virtual function.
+ It is also used for the ANSI fgetpos and fsetpos functions. */
+/* The _IO_seek_cur and _IO_seek_end options are not allowed. */
+typedef _IO_fpos_t (*_IO_seekpos_t) __P((_IO_FILE*, _IO_fpos_t, int));
#define _IO_SEEKPOS(FP, POS, FLAGS) JUMP2(__seekpos, FP, POS, FLAGS)
+
+/* The 'setbuf' hook gives a buffer to the file.
+ It matches the streambuf::setbuf virtual function. */
+typedef _IO_FILE* (*_IO_setbuf_t) __P((_IO_FILE*, char *, _IO_ssize_t));
#define _IO_SETBUF(FP, BUFFER, LENGTH) JUMP2(__setbuf, FP, BUFFER, LENGTH)
+
+/* The 'sync' hook attempts to synchronize the internal data structures
+ of the file with the external state.
+ It matches the streambuf::sync virtual function. */
+typedef int (*_IO_sync_t) __P((_IO_FILE*));
#define _IO_SYNC(FP) JUMP0(__sync, FP)
+
+/* The 'doallocate' hook is used to tell the file to allocate a buffer.
+ It matches the streambuf::doallocate virtual function, which is not
+ in the ANSI/ISO C++ standard, but is part traditional implementations. */
+typedef int (*_IO_doallocate_t) __P((_IO_FILE*));
#define _IO_DOALLOCATE(FP) JUMP0(__doallocate, FP)
+
+/* The following four hooks (sysread, syswrite, sysclose, sysseek, and
+ sysstat) are low-level hooks specific to this implementation.
+ There is no correspondance in the ANSI/ISO C++ standard library.
+ The hooks basically correspond to the Unix system functions
+ (read, write, close, lseek, and stat) except that a _IO_FILE*
+ parameter is used instead of a integer file descriptor; the default
+ implementation used for normal files just calls those functions.
+ The advantage of overriding these functions instead of the higher-level
+ ones (underflow, overflow etc) is that you can leave all the buffering
+ higher-level functions. */
+
+/* The 'sysread' hook is used to read data from the external file into
+ an existing buffer. It generalizes the Unix read(2) function.
+ It matches the streambuf::sys_read virtual function, which is
+ specific to this implementaion. */
+typedef _IO_ssize_t (*_IO_read_t) __P((_IO_FILE*, void*, _IO_ssize_t));
#define _IO_SYSREAD(FP, DATA, LEN) JUMP2(__read, FP, DATA, LEN)
+
+/* The 'syswrite' hook is used to write data from an existing buffer
+ to an external file. It generalizes the Unix write(2) function.
+ It matches the streambuf::sys_write virtual function, which is
+ specific to this implementaion. */
+typedef _IO_ssize_t (*_IO_write_t) __P((_IO_FILE*,const void*,_IO_ssize_t));
#define _IO_SYSWRITE(FP, DATA, LEN) JUMP2(__write, FP, DATA, LEN)
+
+/* The 'sysseek' hook is used to re-position an external file.
+ It generalizes the Unix lseek(2) function.
+ It matches the streambuf::sys_seek virtual function, which is
+ specific to this implementaion. */
+typedef _IO_fpos_t (*_IO_seek_t) __P((_IO_FILE*, _IO_off_t, int));
#define _IO_SYSSEEK(FP, OFFSET, MODE) JUMP2(__seek, FP, OFFSET, MODE)
+
+/* The 'sysclose' hook is used to finalize (close, finish up) an
+ external file. It generalizes the Unix close(2) function.
+ It matches the streambuf::sys_close virtual function, which is
+ specific to this implementation. */
+typedef int (*_IO_close_t) __P((_IO_FILE*)); /* finalize */
#define _IO_SYSCLOSE(FP) JUMP0(__close, FP)
+
+/* The 'sysstat' hook is used to get information about an external file
+ into a struct stat buffer. It generalizes the Unix fstat(2) call.
+ It matches the streambuf::sys_stat virtual function, which is
+ specific to this implementaion. */
+typedef int (*_IO_stat_t) __P((_IO_FILE*, void*));
#define _IO_SYSSTAT(FP, BUF) JUMP1(__stat, FP, BUF)
+
#define _IO_CHAR_TYPE char /* unsigned char ? */
#define _IO_INT_TYPE int
struct _IO_jump_t {
JUMP_FIELD(_G_size_t, __dummy);
+#ifdef _G_USING_THUNKS
+ JUMP_FIELD(_G_size_t, __dummy2);
+#endif
JUMP_FIELD(_IO_finish_t, __finish);
JUMP_FIELD(_IO_overflow_t, __overflow);
JUMP_FIELD(_IO_underflow_t, __underflow);
};
/* We always allocate an extra word following an _IO_FILE.
+ This contains a pointer to the function jump table used.
This is for compatibility with C++ streambuf; the word can
be used to smash to a pointer to a virtual function table. */
struct _IO_FILE_plus {
_IO_FILE file;
-#if _IO_UNIFIED_JUMPTABLES
const struct _IO_jump_t *vtable;
-#else
- const void *vtable;
-#endif
};
/* Generic functions */
#define _IO_have_backup(fp) ((fp)->_IO_save_base != NULL)
#define _IO_in_backup(fp) ((fp)->_flags & _IO_IN_BACKUP)
#define _IO_have_markers(fp) ((fp)->_markers != NULL)
-#define _IO_blen(p) ((fp)->_IO_buf_end - (fp)->_IO_buf_base)
+#define _IO_blen(fp) ((fp)->_IO_buf_end - (fp)->_IO_buf_base)
/* Jumptable functions for files. */
#define EOF (-1)
#endif
#ifndef NULL
-#if !defined(__cplusplus) || defined(__GNUC__)
+#ifdef __GNUG__
+#define NULL (__null)
+#else
+#if !defined(__cplusplus)
#define NULL ((void*)0)
#else
#define NULL (0)
#endif
#endif
+#endif
#define FREE_BUF(_B) free(_B)
#define ALLOC_BUF(_S) (char*)malloc(_S)
}
#endif
-#if _IO_UNIFIED_JUMPTABLES
-#define _IO_FJUMP /* nothing */
-#else
-#define _IO_FJUMP &_IO_file_jumps,
-#endif
#ifdef _IO_MTSAFE_IO
/* check following! */
#define FILEBUF_LITERAL(CHAIN, FLAGS, FD) \
{ _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, _IO_FJUMP FD, \
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, FD, \
0, 0, 0, 0, { 0 }, &_IO_stdfile_##FD##_lock }
#else
/* check following! */
#define FILEBUF_LITERAL(CHAIN, FLAGS, FD) \
{ _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, _IO_FJUMP FD }
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, FD }
#endif
/* VTABLE_LABEL defines NAME as of the CLASS class.
#define MAYBE_SET_EINVAL /* nothing */
#endif
-#ifdef DEBUG
+#ifdef IO_DEBUG
#define CHECK_FILE(FILE,RET) \
if ((FILE) == NULL) { MAYBE_SET_EINVAL; return RET; } \
else { COERCE_FILE(FILE); \
if (new_f == NULL)
return NULL;
#ifdef _IO_MTSAFE_IO
- new_f->fp._sf._f._lock = &new_f->lock;
+ new_f->fp._sf._sbf._f._lock = &new_f->lock;
#endif
buf = ALLOC_BUF (_IO_BUFSIZ);
- _IO_init (&new_f->fp._sf._f, 0);
- _IO_JUMPS (&new_f->fp._sf._f) = &_IO_mem_jumps;
- _IO_str_init_static (&new_f->fp._sf._f, buf, _IO_BUFSIZ, buf);
- new_f->fp._sf._f._flags &= ~_IO_USER_BUF;
+ _IO_init (&new_f->fp._sf._sbf._f, 0);
+ _IO_JUMPS (&new_f->fp._sf._sbf._f) = &_IO_mem_jumps;
+ _IO_str_init_static (&new_f->fp._sf._sbf._f, buf, _IO_BUFSIZ, buf);
+ new_f->fp._sf._sbf._f._flags &= ~_IO_USER_BUF;
new_f->fp._sf._s._allocate_buffer = (_IO_alloc_type) malloc;
new_f->fp._sf._s._free_buffer = (_IO_free_type) free;
new_f->fp.bufloc = bufloc;
new_f->fp.sizeloc = sizeloc;
- return &new_f->fp._sf._f;
+ return &new_f->fp._sf._sbf._f;
}
#include <stdio_lim.h>
+#ifdef __USE_SVID
+/* Default path prefix for `tempnam' and `tmpnam'. */
#define P_tmpdir "/tmp"
+#endif
/* For use by debuggers. These are linked in if printf or fprintf are used. */
extern FILE *stdin, *stdout, *stderr; /* TODO */
_IO_free_type _free_buffer;
};
-typedef struct _IO_strfile_
+/* This is needed for the Irix6 N32 ABI, which has a 64 bit off_t type,
+ but a 32 bit pointer type. In this case, we get 4 bytes of padding
+ after the vtable pointer. Putting them in a structure together solves
+ this problem. */
+
+struct _IO_streambuf
{
struct _IO_FILE _f;
const void *_vtable;
+};
+
+typedef struct _IO_strfile_
+{
+ struct _IO_streambuf _sbf;
struct _IO_str_fields _s;
} _IO_strfile;
+
+/* dynamic: set when the array object is allocated (or reallocated) as
+ necessary to hold a character sequence that can change in length. */
+#define _IO_STR_DYNAMIC(FP) ((FP)->_s._allocate_buffer != (_IO_alloc_type)0)
+
+/* frozen: set when the program has requested that the array object not
+ be altered, reallocated, or freed. */
+#define _IO_STR_FROZEN(FP) ((FP)->_f._IO_file_flags & _IO_USER_BUF)
if (string == NULL)
return -1;
#ifdef _IO_MTSAFE_IO
- sf._f._lock = &lock;
+ sf._sbf._f._lock = &lock;
#endif
_IO_init((_IO_FILE*)&sf, 0);
_IO_JUMPS((_IO_FILE*)&sf) = &_IO_str_jumps;
_IO_str_init_static ((_IO_FILE*)&sf, string, init_string_size, string);
- sf._f._flags &= ~_IO_USER_BUF;
+ sf._sbf._f._flags &= ~_IO_USER_BUF;
sf._s._allocate_buffer = (_IO_alloc_type)malloc;
sf._s._free_buffer = (_IO_free_type)free;
ret = _IO_vfprintf((_IO_FILE*)&sf, format, args);
if (ret < 0)
return ret;
- *result_ptr = (char*)realloc(sf._f._IO_buf_base,
- (sf._f._IO_write_ptr - sf._f._IO_write_base) +1);
+ *result_ptr = (char*)realloc(sf._sbf._f._IO_buf_base,
+ (sf._sbf._f._IO_write_ptr - sf._sbf._f._IO_write_base) +1);
if (*result_ptr == NULL)
- *result_ptr = sf._f._IO_buf_base;
- (*result_ptr)[sf._f._IO_write_ptr-sf._f._IO_write_base] = '\0';
+ *result_ptr = sf._sbf._f._IO_buf_base;
+ (*result_ptr)[sf._sbf._f._IO_write_ptr-sf._sbf._f._IO_write_base] = '\0';
return ret;
}
weak_alias (_IO_vasprintf, vasprintf)
int ret;
#ifdef _IO_MTSAFE_IO
_IO_lock_t lock;
- sf._f._lock = &lock;
+ sf._sbf._f._lock = &lock;
#endif
_IO_init ((_IO_FILE *) &sf, 0);
_IO_JUMPS ((_IO_FILE *) &sf) = &_IO_str_jumps;
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <utmp.h>
-
-
-/* The global data defined in setutent.c. */
-extern struct utmp_data __utmp_data;
-
-
-void
-endutent (void)
-{
- __endutent_r (&__utmp_data);
-}
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <unistd.h>
-#include <utmp.h>
-
-
-void
-__endutent_r (struct utmp_data *utmp_data)
-{
- if (utmp_data->ut_fd != -1)
- {
- close (utmp_data->ut_fd);
- utmp_data->ut_fd = -1;
- }
-}
-weak_alias (__endutent_r, endutent_r)
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <utmp.h>
-
-
-/* The global data defined in setutent.c. */
-extern struct utmp_data __utmp_data;
-
-
-struct utmp *
-pututline (const struct utmp *utmp)
-{
- if (__pututline_r (utmp, &__utmp_data) < 0)
- return NULL;
-
- return (struct utmp *) utmp;
-}
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <alloca.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <utmp.h>
-#include <sys/file.h>
-#include <sys/stat.h>
-
-
-/* XXX An alternative solution would be to call a SUID root program
- which write the new value. */
-
-int
-__pututline_r (const struct utmp *id, struct utmp_data *utmp_data)
-{
- struct stat st;
- int result = 0;
-
-#if _HAVE_UT_TYPE - 0
- /* Test whether ID has any of the legal types because we have to
- prevent illegal entries. */
- if (id->ut_type != RUN_LVL && id->ut_type != BOOT_TIME
- && id->ut_type != OLD_TIME && id->ut_type != NEW_TIME
- && id->ut_type != INIT_PROCESS && id->ut_type != LOGIN_PROCESS
- && id->ut_type != USER_PROCESS && id->ut_type != DEAD_PROCESS)
- /* No, using '<' and '>' for the test is not possible. */
- {
- __set_errno (EINVAL);
- return -1;
- }
-#endif
-
- /* Open utmp file if not already done. */
- if (utmp_data->ut_fd == -1)
- {
- setutent_r (utmp_data);
- if (utmp_data->ut_fd == -1)
- return -1;
- }
-
-#if _HAVE_UT_ID - 0
- /* Check whether we need to reposition. Repositioning is necessary
- either if the data in UTMP_DATA is not valid or if the ids don't
- match: */
- if (id->ut_id[0]
- && (utmp_data->loc_utmp < (off_t) sizeof (struct utmp)
- || strncmp (utmp_data->ubuf.ut_id, id->ut_id,
- sizeof (id->ut_id)) != 0))
- {
- /* We must not overwrite the data in UTMP_DATA since ID may be
- aliasing it. */
- struct utmp_data *data_tmp = alloca (sizeof (*data_tmp));
- struct utmp *dummy;
-
- *data_tmp = *utmp_data;
- utmp_data = data_tmp;
-
- if (getutid_r (id, &dummy, utmp_data) < 0 && errno != ESRCH)
- return -1;
- }
-#endif
-
- /* Try to lock the file. */
- if (flock (utmp_data->ut_fd, LOCK_EX | LOCK_NB) < 0 && errno != ENOSYS)
- {
- /* Oh, oh. The file is already locked. Wait a bit and try again. */
- sleep (1);
-
- /* This time we ignore the error. */
- (void) flock (utmp_data->ut_fd, LOCK_EX | LOCK_NB);
- }
-
- /* Find out how large the file is. */
- result = fstat (utmp_data->ut_fd, &st);
-
- if (result >= 0)
- /* Position file correctly. */
- if (utmp_data->loc_utmp < (off_t) sizeof (struct utmp)
- || (off_t) (utmp_data->loc_utmp - sizeof (struct utmp)) > st.st_size)
- /* Not located at any valid entry. Add at the end. */
- {
- result = lseek (utmp_data->ut_fd, 0L, SEEK_END);
- if (result >= 0)
- /* Where we'll be if the write succeeds. */
- utmp_data->loc_utmp = st.st_size + sizeof (struct utmp);
- }
- else
- result =
- lseek (utmp_data->ut_fd, utmp_data->loc_utmp - sizeof (struct utmp),
- SEEK_SET);
-
- if (result >= 0)
- /* Write the new data. */
- if (write (utmp_data->ut_fd, id, sizeof (struct utmp))
- != sizeof (struct utmp))
- {
- /* If we appended a new record this is only partially written.
- Remove it. */
- if (utmp_data->loc_utmp > st.st_size)
- {
- (void) ftruncate (utmp_data->ut_fd, st.st_size);
- utmp_data->loc_utmp = st.st_size;
- }
-
- result = -1;
- }
-
- /* And unlock the file. */
- (void) flock (utmp_data->ut_fd, LOCK_UN);
-
- return result;
-}
-weak_alias (__pututline_r, pututline_r)
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <utmp.h>
-
-/* Global variable with values for non-reentrent functions. If must
- be initialized so that field `ut_fd' is set to -1. */
-struct utmp_data __utmp_data = { ut_fd: -1 };
-
-
-void
-setutent (void)
-{
- __setutent_r (&__utmp_data);
-}
+++ /dev/null
-/* Copyright (C) 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
-Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
-
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
-
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <utmp.h>
-
-/* This is the default name. */
-static const char default_utmp_name[] = _PATH_UTMP;
-
-/* Current file name. */
-static const char *utmp_file_name = (const char *) default_utmp_name;
-
-
-void
-__setutent_r (struct utmp_data *utmp_data)
-{
- /* Before the UTMP_DATA is used before the first time the UT_FD
- field must be set to -1. */
- if (utmp_data->ut_fd == -1)
- {
- utmp_data->ut_fd = open (utmp_file_name, O_RDWR);
- if (utmp_data->ut_fd == -1)
- {
- /* Hhm, read-write access did not work. Try read-only. */
- utmp_data->ut_fd = open (utmp_file_name, O_RDONLY);
- if (utmp_data->ut_fd == -1)
- {
- perror (_("while opening UTMP file"));
- return;
- }
- }
- }
-
- /* Remember we are at beginning of file. */
- utmp_data->loc_utmp = 0;
-#if _HAVE_UT_TYPE - 0
- utmp_data->ubuf.ut_type = UT_UNKNOWN;
-#endif
-}
-weak_alias (__setutent_r, setutent_r)
-
-
-int
-__utmpname (const char *file)
-{
- char *fname = __strdup (file);
- if (fname == NULL)
- return 0;
-
- if (utmp_file_name != default_utmp_name)
- free ((void *) utmp_file_name);
-
- utmp_file_name = fname;
-
- return 1;
-}
-weak_alias (__utmpname, utmpname)
-@node Floating-Point Limits
+@node Floating-Point Limits
@chapter Floating-Point Limits
@pindex <float.h>
@cindex floating-point number representation
@cindex mantissa (of floating-point number)
@cindex significand (of floating-point number)
-@item
+@item
The @dfn{precision} of the mantissa. If the base of the representation
is @var{b}, then the precision is the number of base-@var{b} digits in
the mantissa. This is a constant for the particular representation.
places that require constant expressions, such as @samp{#if}
preprocessing directives and array size specifications.
-Although the ANSI C standard specifies minimum and maximum values for
+Although the @w{ISO C} standard specifies minimum and maximum values for
most of these parameters, the GNU C implementation uses whatever
floating-point representations are supported by the underlying hardware.
-So whether GNU C actually satisfies the ANSI C requirements depends on
+So whether GNU C actually satisfies the @w{ISO C} requirements depends on
what machine it is running on.
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_ROUNDS
This value characterizes the rounding mode for floating-point addition.
The following values indicate standard rounding modes:
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_RADIX
This is the value of the base, or radix, of exponent representation.
This is guaranteed to be a constant expression, unlike the other macros
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{float} data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{double} data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{long double} data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_DIG
This is the number of decimal digits of precision for the @code{float}
data type. Technically, if @var{p} and @var{b} are the precision and
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_DIG
This is similar to @code{FLT_DIG}, but is for the @code{double} data
type. The value of this macro is guaranteed to be at least @code{10}.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_DIG
This is similar to @code{FLT_DIG}, but is for the @code{long double}
data type. The value of this macro is guaranteed to be at least
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MIN_EXP
This is the minimum negative integer such that the mathematical value
@code{FLT_RADIX} raised to this power minus 1 can be represented as a
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MIN_EXP
This is similar to @code{FLT_MIN_EXP}, but is for the @code{double} data
type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MIN_EXP
This is similar to @code{FLT_MIN_EXP}, but is for the @code{long double}
data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MIN_10_EXP
This is the minimum negative integer such that the mathematical value
@code{10} raised to this power minus 1 can be represented as a
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MIN_10_EXP
This is similar to @code{FLT_MIN_10_EXP}, but is for the @code{double}
data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MIN_10_EXP
This is similar to @code{FLT_MIN_10_EXP}, but is for the @code{long
double} data type.
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MAX_EXP
This is the maximum negative integer such that the mathematical value
@code{FLT_RADIX} raised to this power minus 1 can be represented as a
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MAX_EXP
This is similar to @code{FLT_MAX_EXP}, but is for the @code{double} data
type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MAX_EXP
This is similar to @code{FLT_MAX_EXP}, but is for the @code{long double}
data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MAX_10_EXP
This is the maximum negative integer such that the mathematical value
@code{10} raised to this power minus 1 can be represented as a
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MAX_10_EXP
This is similar to @code{FLT_MAX_10_EXP}, but is for the @code{double}
data type.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MAX_10_EXP
This is similar to @code{FLT_MAX_10_EXP}, but is for the @code{long
double} data type.
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MAX
The value of this macro is the maximum representable floating-point
number of type @code{float}, and is guaranteed to be at least
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MAX
The value of this macro is the maximum representable floating-point
number of type @code{double}, and is guaranteed to be at least
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MAX
The value of this macro is the maximum representable floating-point
number of type @code{long double}, and is guaranteed to be at least
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{float}, and is
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{double}, and
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{long double},
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro FLT_EPSILON
This is the minimum positive floating-point number of type @code{float}
such that @code{1.0 + FLT_EPSILON != 1.0} is true. It's guaranteed to
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro DBL_EPSILON
This is similar to @code{FLT_EPSILON}, but is for the @code{double}
type. The maximum value is @code{1E-9}.
@end defvr
@comment float.h
-@comment ANSI
+@comment ISO
@defvr Macro LDBL_EPSILON
This is similar to @code{FLT_EPSILON}, but is for the @code{long double}
type. The maximum value is @code{1E-9}.
Here is an example showing how these parameters work for a common
floating point representation, specified by the @cite{IEEE Standard for
-Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985)}.
+Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985 or ANSI/IEEE
+Std 854-1987)}.
The IEEE single-precision float representation uses a base of 2. There
is a sign bit, a mantissa with 23 bits plus one hidden bit (so the total
FLT_MAX 3.40282347E+38F
FLT_EPSILON 1.19209290E-07F
@end example
-
-
-
* Floating-Point Limits :: Parameters which characterize
supported floating-point
representations on a particular
- system.
+ system.
@end menu
@node Integer Representation Limits, Floating-Point Limits , , Representation Limits
@pindex limits.h
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int CHAR_BIT
This is the number of bits in a @code{char}, usually eight.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SCHAR_MIN
This is the minimum value that can be represented by a @code{signed char}.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SCHAR_MAX
This is the maximum value that can be represented by a @code{signed char}.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int UCHAR_MAX
This is the maximum value that can be represented by a @code{unsigned char}.
(The minimum value of an @code{unsigned char} is zero.)
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int CHAR_MIN
This is the minimum value that can be represented by a @code{char}.
It's equal to @code{SCHAR_MIN} if @code{char} is signed, or zero
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int CHAR_MAX
This is the maximum value that can be represented by a @code{char}.
It's equal to @code{SCHAR_MAX} if @code{char} is signed, or
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SHRT_MIN
This is the minimum value that can be represented by a @code{signed
short int}. On most machines that the GNU C library runs on,
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SHRT_MAX
This is the maximum value that can be represented by a @code{signed
short int}.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int USHRT_MAX
This is the maximum value that can be represented by an @code{unsigned
short int}. (The minimum value of an @code{unsigned short int} is zero.)
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int INT_MIN
This is the minimum value that can be represented by a @code{signed
int}. On most machines that the GNU C system runs on, an @code{int} is
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int INT_MAX
This is the maximum value that can be represented by a @code{signed
int}.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {unsigned int} UINT_MAX
This is the maximum value that can be represented by an @code{unsigned
int}. (The minimum value of an @code{unsigned int} is zero.)
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {long int} LONG_MIN
This is the minimum value that can be represented by a @code{signed long
int}. On most machines that the GNU C system runs on, @code{long}
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {long int} LONG_MAX
This is the maximum value that can be represented by a @code{signed long
int}.
@end deftypevr
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {unsigned long int} ULONG_MAX
This is the maximum value that can be represented by an @code{unsigned
long int}. (The minimum value of an @code{unsigned long int} is zero.)
@menu
* Floating-Point Representation:: Definitions of terminology.
* Floating-Point Parameters:: Descriptions of the library
- facilities.
+ facilities.
* IEEE Floating Point:: An example of a common
- representation.
+ representation.
@end menu
@node Floating-Point Representation, Floating-Point Parameters, , Floating-Point Limits
@cindex mantissa (of floating-point number)
@cindex significand (of floating-point number)
-@item
+@item
The @dfn{precision} of the mantissa. If the base of the representation
is @var{b}, then the precision is the number of base-@var{b} digits in
the mantissa. This is a constant for the particular representation.
places that require constant expressions, such as @samp{#if}
preprocessing directives or array size specifications.
-Although the ANSI C standard specifies minimum and maximum values for
+Although the @w{ISO C} standard specifies minimum and maximum values for
most of these parameters, the GNU C implementation uses whatever
floating-point representations are supported by the underlying hardware.
-So whether GNU C actually satisfies the ANSI C requirements depends on
+So whether GNU C actually satisfies the @w{ISO C} requirements depends on
what machine it is running on.
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_ROUNDS
This value characterizes the rounding mode for floating-point addition.
The following values indicate standard rounding modes:
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_RADIX
This is the value of the base, or radix, of exponent representation.
This is guaranteed to be a constant expression, unlike the other macros
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{float} data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{double} data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating-point
mantissa for the @code{long double} data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_DIG
This is the number of decimal digits of precision for the @code{float}
data type. Technically, if @var{p} and @var{b} are the precision and
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_DIG
This is similar to @code{FLT_DIG}, but is for the @code{double} data
type. The value of this macro is guaranteed to be at least @code{10}.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_DIG
This is similar to @code{FLT_DIG}, but is for the @code{long double}
data type. The value of this macro is guaranteed to be at least
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_MIN_EXP
This is the minimum negative integer such that the mathematical value
@code{FLT_RADIX} raised to this power minus 1 can be represented as a
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_MIN_EXP
This is similar to @code{FLT_MIN_EXP}, but is for the @code{double} data
type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_MIN_EXP
This is similar to @code{FLT_MIN_EXP}, but is for the @code{long double}
data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_MIN_10_EXP
This is the minimum negative integer such that the mathematical value
@code{10} raised to this power minus 1 can be represented as a
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_MIN_10_EXP
This is similar to @code{FLT_MIN_10_EXP}, but is for the @code{double}
data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_MIN_10_EXP
This is similar to @code{FLT_MIN_10_EXP}, but is for the @code{long
double} data type.
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_MAX_EXP
This is the maximum negative integer such that the mathematical value
@code{FLT_RADIX} raised to this power minus 1 can be represented as a
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_MAX_EXP
This is similar to @code{FLT_MAX_EXP}, but is for the @code{double} data
type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_MAX_EXP
This is similar to @code{FLT_MAX_EXP}, but is for the @code{long double}
data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FLT_MAX_10_EXP
This is the maximum negative integer such that the mathematical value
@code{10} raised to this power minus 1 can be represented as a
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int DBL_MAX_10_EXP
This is similar to @code{FLT_MAX_10_EXP}, but is for the @code{double}
data type.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int LDBL_MAX_10_EXP
This is similar to @code{FLT_MAX_10_EXP}, but is for the @code{long
double} data type.
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double FLT_MAX
The value of this macro is the maximum representable floating-point
number of type @code{float}, and is guaranteed to be at least
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double DBL_MAX
The value of this macro is the maximum representable floating-point
number of type @code{double}, and is guaranteed to be at least
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {long double} LDBL_MAX
The value of this macro is the maximum representable floating-point
number of type @code{long double}, and is guaranteed to be at least
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double FLT_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{float}, and is
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double DBL_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{double}, and
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {long double} LDBL_MIN
The value of this macro is the minimum normalized positive
floating-point number that is representable by type @code{long double},
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double FLT_EPSILON
This is the minimum positive floating-point number of type @code{float}
such that @code{1.0 + FLT_EPSILON != 1.0} is true. It's guaranteed to
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double DBL_EPSILON
This is similar to @code{FLT_EPSILON}, but is for the @code{double}
type. The maximum value is @code{1E-9}.
@end deftypevr
@comment float.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {long double} LDBL_EPSILON
This is similar to @code{FLT_EPSILON}, but is for the @code{long double}
type. The maximum value is @code{1E-9}.
@node IEEE Floating Point, , Floating-Point Parameters, Floating-Point Limits
@subsection IEEE Floating Point
-@cindex IEEE floating-point representation
+@cindex IEEE floating-point representation
@cindex floating-point, IEEE
@cindex IEEE Std 754
Here is an example showing how these parameters work for a common
floating point representation, specified by the @cite{IEEE Standard for
-Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985)}. Nearly
-all computers today use this format.
+Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985 or ANSI/IEEE
+Std 854-1987)}. Nearly all computers today use this format.
The IEEE single-precision float representation uses a base of 2. There
is a sign bit, a mantissa with 23 bits plus one hidden bit (so the total
see @ref{Classification of Characters}).
@item
-Certain options require an argument. For example, the @samp{-o}
+Certain options require an argument. For example, the @samp{-o}
command of the ld command requires an argument---an output file name.
@item
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} getenv (const char *@var{name})
This function returns a string that is the value of the environment
variable @var{name}. You must not modify this string. In some systems
You can deal directly with the underlying representation of environment
objects to add more variables to the environment (for example, to
communicate with another program you are about to execute; see
-@ref{Executing a File}).
+@ref{Executing a File}).
@comment unistd.h
@comment POSIX.1
which are implemented in terms of those functions.
The syntax of a path is a sequence of directory names separated by
-colons. An empty string instead of a directory name stands for the
+colons. An empty string instead of a directory name stands for the
current directory. (@xref{Working Directory}.)
A typical value for this environment variable might be a string like:
a terminal that kills the program.
@menu
-* Normal Program Termination::
+* Normal Program Termination::
* Exit Status:: Exit Status
* Cleanups on Exit:: Cleanups on Exit
-* Aborting a Program::
+* Aborting a Program::
* Termination Internals:: Termination Internals
@end menu
@subsection Normal Program Termination
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void exit (int @var{status})
The @code{exit} function causes normal program termination with status
@var{status}. This function does not return.
sequence:
@enumerate
-@item
+@item
Functions that were registered with the @code{atexit} or @code{on_exit}
functions are called in the reverse order of their registration. This
mechanism allows your application to specify its own ``cleanup'' actions
things like saving program state information in a file, or unlock locks
in shared data bases.
-@item
+@item
All open streams are closed; writing out any buffered output data. See
@ref{Opening and Closing Streams}. In addition, temporary files opened
with the @code{tmpfile} function are removed; see @ref{Temporary Files}.
-@item
+@item
@code{_exit} is called. @xref{Termination Internals}
@end enumerate
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int EXIT_SUCCESS
This macro can be used with the @code{exit} function to indicate
successful program completion.
@end deftypevr
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int EXIT_FAILURE
This macro can be used with the @code{exit} function to indicate
unsuccessful program completion in a general sense.
@subsection Cleanups on Exit
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int atexit (void (*@var{function}))
The @code{atexit} function registers the function @var{function} to be
called at normal program termination. The @var{function} is called with
no arguments.
The return value from @code{atexit} is zero on success and nonzero if
-the function cannot be registered.
+the function cannot be registered.
@end deftypefun
@comment stdlib.h
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void abort ()
The @code{abort} function causes abnormal program termination, without
executing functions registered with @code{atexit} or @code{on_exit}.
program.
* Process Completion:: How to tell when a child process has
completed.
-* Process Completion Status:: How to interpret the status value
+* Process Completion Status:: How to interpret the status value
returned from a child process.
* BSD wait Functions:: More functions, for backward
compatibility.
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int system (const char *@var{command})
This function executes @var{command} as a shell command. In the GNU C
library, it always uses the default shell @code{sh} to run the command.
The set of pending signals (@pxref{Delivery of Signal}) for the child
process is cleared. (The child process inherits its mask of blocked
signals and signal actions from the parent process.)
-@end itemize
+@end itemize
@comment unistd.h
@deftypefun int execve (const char *@var{filename}, char *const @var{argv}@t{[]}, char *const @var{env}@t{[]})
This is similar to @code{execv}, but permits you to specify the environment
for the new program explicitly as the @var{env} argument. This should
-be an array of strings in the same format as for the @code{environ}
+be an array of strings in the same format as for the @code{environ}
variable; see @ref{Environment Access}.
@end deftypefun
If @var{usage} is a null pointer, this function is equivalent to
@code{waitpid (-1, @var{status_ptr}, @var{options})}.
-The @var{usage} argument may also be a pointer to a
+The @var{usage} argument may also be a pointer to a
@code{struct rusage} object. Information about system resources used by
terminated processes (but not stopped processes) is returned in this
structure.
If @var{usage} is a null pointer, this function is equivalent to
@code{waitpid (@var{pid}, @var{status_ptr}, @var{options})}.
-The @var{usage} argument may also be a pointer to a
+The @var{usage} argument may also be a pointer to a
@code{struct rusage} object. Information about system resources used by
terminated processes (but not stopped processes) is returned in this
structure.
/* @r{Execute the command using this shell program.} */
#define SHELL "/bin/sh"
-int
+int
my_system (char *command)
@{
int status;
Remember that the first @code{argv} argument supplied to the program
represents the name of the program being executed. That is why, in the
call to @code{execl}, @code{SHELL} is supplied once to name the program
-to execute and a second time to supply a value for @code{argv[0]}.
+to execute and a second time to supply a value for @code{argv[0]}.
The @code{execl} call in the child process doesn't return if it is
successful. If it fails, you must do something to make the child
@cindex variable number of arguments
@cindex optional arguments
-ANSI C defines a syntax as part of the kernel language for specifying
+@w{ISO C} defines a syntax as part of the kernel language for specifying
functions that take a variable number or type of arguments. (Such
functions are also referred to as @dfn{variadic functions}.) However,
the kernel language provides no mechanism for actually accessing
arguments as specified in the function definition.
On the other hand, sometimes a function performs an operation that can
-meaningfully accept an unlimited number of arguments.
+meaningfully accept an unlimited number of arguments.
For example, consider a function that joins its arguments into a linked
list. It makes sense to connect any number of arguments together into a
@samp{@dots{}} at the end of the arguments. For example,
@example
-int
+int
func (const char *a, int b, @dots{})
@{
@dots{}
-@}
+@}
@end example
@noindent
@code{int} and takes at least two arguments, the first two being a
@code{const char *} and an @code{int}.@refill
-An obscure restriction placed by the ANSI C standard is that the last
+An obscure restriction placed by the @w{ISO C} standard is that the last
required argument must not be declared @code{register} in the function
definition. Furthermore, this argument must not be of a function or
array type, and may not be, for example, a @code{char} or @code{short
@strong{Compatibility Note:} Many older C dialects provide a similar,
but incompatible, mechanism for defining functions with variable numbers
of arguments. In particular, the @samp{@dots{}} syntax is a new feature
-of ANSI C.
+of @w{ISO C}.
@node Receiving the Argument Values, How Many Arguments, Syntax for Variable Arguments, How Variable Arguments are Used
@pindex stdarg.h
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} va_list
The type @code{va_list} is used for argument pointer variables.
@end deftp
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} void va_start (va_list @var{ap}, @var{last_required})
This macro initialized the argument pointer variable @var{ap} to point
to the first of the optional arguments of the current function;
@end deftypefn
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} @var{type} va_arg (va_list @var{ap}, @var{type})
The @code{va_arg} macro returns the value of the next optional argument,
and changes the internal state of @var{ap} to move past this argument.
-Thus, successive uses of @code{va_arg} return successive optional
+Thus, successive uses of @code{va_arg} return successive optional
arguments.
The type of the value returned by @code{va_arg} is the @var{type}
-specified in the call.
+specified in the call.
The @var{type} must match the type of the actual argument, and must not
be @code{char} or @code{short int} or @code{float}. (Remember that the
@end deftypefn
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} void va_end (va_list @var{ap})
This ends the use of @var{ap}. After a @code{va_end} call, further
@code{va_arg} calls with the same @var{ap} may not work. You should invoke
@example
#include <stdarg.h>
-int
+int
add_em_up (int count, @dots{})
@{
va_list ap;
@pindex stddef.h
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} ptrdiff_t
This is the signed integer type of the result of subtracting two
pointers. For example, with the declaration @code{char *p1, *p2;}, the
@end deftp
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} size_t
This is an unsigned integer type used to represent the sizes of objects.
The result of the @code{sizeof} operator is of this type, and functions
object sizes.
@end deftp
-In the GNU system @code{size_t} is equivalent to one of the types
+In the GNU system @code{size_t} is equivalent to one of the types
@code{unsigned int} and @code{unsigned long int}. These types have
identical properties on the GNU system, and for most purposes, you
-can use them interchangeably. However, they are distinct types,
+can use them interchangeably. However, they are distinct types,
and in certain contexts, you may not treat them as identical. For
-example, when you specify the type of a function argument in a
+example, when you specify the type of a function argument in a
function prototype, it makes a difference which one you use. If
the system header files declare @code{malloc} with an argument
of type @code{size_t} and you declare @code{malloc} with an argument
actually be.
@strong{Compatibility Note:} Types such as @code{size_t} are new
-features of ANSI C. Older, pre-ANSI C implementations have
+features of @w{ISO C}. Older, pre-ANSI C implementations have
traditionally used @code{unsigned int} for representing object sizes
and @code{int} for pointer subtraction results.
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {void *} NULL
@cindex null pointer
This is a null pointer constant. It can be assigned to any pointer
point to any real object. This macro is the best way to get a null
pointer value. You can also use @code{0} or @code{(void *)0} as a null
pointer constant, but using @code{NULL} makes the purpose of the
-constant more evident.
+constant more evident.
When passing a null pointer as an argument to a function for which there
is no prototype declaration in scope, you should explicitly cast
@end deftypevr
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} size_t offsetof (@var{type}, @var{member})
This expands to a integer constant expression that is the offset of the
structure member named @var{member} in a @code{struct} of type
In the BSD library, on certain machines, @code{infnan} raises a fatal
signal in all cases. The GNU library does not do likewise, because that
-does not fit the ANSI C specification.
+does not fit the @w{ISO C} specification.
@end deftypefun
@strong{Portability Note:} The functions listed in this section are BSD
@code{fabs} and @code{cabs} are declared in @file{math.h}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int abs (int @var{number})
This function returns the absolute value of @var{number}.
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {long int} labs (long int @var{number})
This is similar to @code{abs}, except that both the argument and result
are of type @code{long int} rather than @code{int}.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double fabs (double @var{number})
This function returns the absolute value of the floating-point number
@var{number}.
All these functions are declared in @file{math.h}.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double frexp (double @var{value}, int *@var{exponent})
The @code{frexp} function is used to split the number @var{value}
into a normalized fraction and an exponent.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double ldexp (double @var{value}, int @var{exponent})
This function returns the result of multiplying the floating-point
number @var{value} by 2 raised to the power @var{exponent}. (It can
result as a @code{double} instead to get around this problem.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double ceil (double @var{x})
The @code{ceil} function rounds @var{x} upwards to the nearest integer,
returning that value as a @code{double}. Thus, @code{ceil (1.5)}
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double floor (double @var{x})
The @code{ceil} function rounds @var{x} downwards to the nearest
integer, returning that value as a @code{double}. Thus, @code{floor
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double modf (double @var{value}, double *@var{integer-part})
This function breaks the argument @var{value} into an integer part and a
fractional part (between @code{-1} and @code{1}, exclusive). Their sum
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double fmod (double @var{numerator}, double @var{denominator})
This function computes the remainder from the division of
@var{numerator} by @var{denominator}. Specifically, the return value is
@file{stdlib.h} in your program.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} div_t
This is a structure type used to hold the result returned by the @code{div}
function. It has the following members:
@end deftp
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun div_t div (int @var{numerator}, int @var{denominator})
This function @code{div} computes the quotient and remainder from
the division of @var{numerator} by @var{denominator}, returning the
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} ldiv_t
This is a structure type used to hold the result returned by the @code{ldiv}
function. It has the following members:
@end deftp
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun ldiv_t ldiv (long int @var{numerator}, long int @var{denominator})
The @code{ldiv} function is similar to @code{div}, except that the
arguments are of type @code{long int} and the result is returned as a
These functions are declared in @file{stdlib.h}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {long int} strtol (const char *@var{string}, char **@var{tailptr}, int @var{base})
The @code{strtol} (``string-to-long'') function converts the initial
part of @var{string} to a signed integer, which is returned as a value
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {unsigned long int} strtoul (const char *@var{string}, char **@var{tailptr}, int @var{base})
The @code{strtoul} (``string-to-unsigned-long'') function is like
@code{strtol} except it deals with unsigned numbers, and returns its
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {long int} atol (const char *@var{string})
This function is similar to the @code{strtol} function with a @var{base}
argument of @code{10}, except that it need not detect overflow errors.
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int atoi (const char *@var{string})
This function is like @code{atol}, except that it returns an @code{int}
value rather than @code{long int}. The @code{atoi} function is also
These functions are declared in @file{stdlib.h}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun double strtod (const char *@var{string}, char **@var{tailptr})
The @code{strtod} (``string-to-double'') function converts the initial
part of @var{string} to a floating-point number, which is returned as a
current locale (@pxref{Parsing of Integers}).
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun double atof (const char *@var{string})
This function is similar to the @code{strtod} function, except that it
need not detect overflow and underflow errors. The @code{atof} function
The normal return value from @code{sysconf} is the value you requested.
A value of @code{-1} is returned both if the implementation does not
-impose a limit, and in case of an error.
+impose a limit, and in case of an error.
The following @code{errno} error conditions are defined for this function:
@c @xref{XXX getpagesize}. !!! ???
@end table
-@node Examples of Sysconf
+@node Examples of Sysconf
@subsection Examples of @code{sysconf}
We recommend that you first test for a macro definition for the
@end deftypevr
@comment stdio.h
-@comment ANSI
-@deftypevr Macro int FILENAME_MAX
+@comment ISO
+@deftypevr Macro int FILENAME_MAX
The value of this macro is an integer constant expression that
represents the maximum length of a file name string. It is defined in
@file{stdio.h}.
@comment POSIX.1
@deftypevr Macro int _POSIX_CHOWN_RESTRICTED
If this option is in effect, the @code{chown} function is restricted so
-that the only changes permitted to nonprivileged processes is to change
+that the only changes permitted to nonprivileged processes is to change
the group owner of a file to either be the effective group ID of the
process, or one of its supplementary group IDs. @xref{File Owner}.
@end deftypevr
is controlled by which @dfn{feature test macros} you define.
If you compile your programs using @samp{gcc -ansi}, you get only the
-ANSI C library features, unless you explicitly request additional
+@w{ISO C} library features, unless you explicitly request additional
features by defining one or more of the feature macros.
@xref{Invoking GCC,, GNU CC Command Options, gcc.info, The GNU CC Manual},
for more information about GCC options.@refill
@defvr Macro _POSIX_SOURCE
If you define this macro, then the functionality from the POSIX.1
standard (IEEE Standard 1003.1) is available, as well as all of the
-ANSI C facilities.
+@w{ISO C} facilities.
@end defvr
@comment (none)
available. If you define this macro with a value of @code{2}, then both
the functionality from the POSIX.1 standard and the functionality from
the POSIX.2 standard (IEEE Standard 1003.2) are made available. This is
-in addition to the ANSI C facilities.
+in addition to the @w{ISO C} facilities.
@end defvr
@comment (none)
@comment GNU
@defvr Macro _BSD_SOURCE
If you define this macro, functionality derived from 4.3 BSD Unix is
-included as well as the ANSI C, POSIX.1, and POSIX.2 material.
+included as well as the @w{ISO C}, POSIX.1, and POSIX.2 material.
Some of the features derived from 4.3 BSD Unix conflict with the
corresponding features specified by the POSIX.1 standard. If this
@comment GNU
@defvr Macro _SVID_SOURCE
If you define this macro, functionality derived from SVID is
-included as well as the ANSI C, POSIX.1, POSIX.2, and X/Open material.
+included as well as the @w{ISO C}, POSIX.1, POSIX.2, and X/Open material.
@end defvr
@comment (none)
@comment (none)
@comment GNU
@defvr Macro _GNU_SOURCE
-If you define this macro, everything is included: ANSI C, POSIX.1,
+If you define this macro, everything is included: @w{ISO C}, POSIX.1,
POSIX.2, BSD, SVID, X/Open, and GNU extensions. In the cases where
POSIX.1 conflicts with BSD, the POSIX definitions take precedence.
Each of them takes one argument, which is a character to test, and
returns an @code{int} which is treated as a boolean value. The
character argument is passed as an @code{int}, and it may be the
-constant value @code{EOF} instead of a real character.
+constant value @code{EOF} instead of a real character.
The attributes of any given character can vary between locales.
@xref{Locales}, for more information on locales.@refill
@cindex lower-case character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int islower (int @var{c})
Returns true if @var{c} is a lower-case letter.
@end deftypefun
@cindex upper-case character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isupper (int @var{c})
Returns true if @var{c} is an upper-case letter.
@end deftypefun
@cindex alphabetic character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isalpha (int @var{c})
Returns true if @var{c} is an alphabetic character (a letter). If
@code{islower} or @code{isupper} is true of a character, then
@cindex digit character
@cindex decimal digit character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isdigit (int @var{c})
Returns true if @var{c} is a decimal digit (@samp{0} through @samp{9}).
@end deftypefun
@cindex alphanumeric character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isalnum (int @var{c})
Returns true if @var{c} is an alphanumeric character (a letter or
number); in other words, if either @code{isalpha} or @code{isdigit} is
@cindex hexadecimal digit character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isxdigit (int @var{c})
Returns true if @var{c} is a hexadecimal digit.
Hexadecimal digits include the normal decimal digits @samp{0} through
@cindex punctuation character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int ispunct (int @var{c})
Returns true if @var{c} is a punctuation character.
This means any printing character that is not alphanumeric or a space
@cindex whitespace character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isspace (int @var{c})
Returns true if @var{c} is a @dfn{whitespace} character. In the standard
@code{"C"} locale, @code{isspace} returns true for only the standard
@cindex graphic character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isgraph (int @var{c})
Returns true if @var{c} is a graphic character; that is, a character
that has a glyph associated with it. The whitespace characters are not
@cindex printing character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int isprint (int @var{c})
Returns true if @var{c} is a printing character. Printing characters
include all the graphic characters, plus the space (@samp{ }) character.
@cindex control character
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int iscntrl (int @var{c})
Returns true if @var{c} is a control character (that is, a character that
is not a printing character).
@code{int}. If the conversion is not applicable to the argument given,
the argument is returned unchanged.
-@strong{Compatibility Note:} In pre-ANSI C dialects, instead of
+@strong{Compatibility Note:} In pre-@w{ISO C} dialects, instead of
returning the argument unchanged, these functions may fail when the
argument is not suitable for the conversion. Thus for portability, you
may need to write @code{islower(c) ? toupper(c) : c} rather than just
@pindex ctype.h
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int tolower (int @var{c})
If @var{c} is an upper-case letter, @code{tolower} returns the corresponding
lower-case letter. If @var{c} is not an upper-case letter,
@end deftypefun
@comment ctype.h
-@comment ANSI
+@comment ISO
@deftypefun int toupper (int @var{c})
If @var{c} is a lower-case letter, @code{tolower} returns the corresponding
upper-case letter. Otherwise @var{c} is returned unchanged.
@pindex errno.h
@comment errno.h
-@comment ANSI
+@comment ISO
@deftypevr {Variable} {volatile int} errno
The variable @code{errno} contains the system error number. You can
change the value of @code{errno}.
assume that any library function might alter @code{errno} when the
function returns an error.
-@strong{Portability Note:} ANSI C specifies @code{errno} as a
+@strong{Portability Note:} @w{ISO C} specifies @code{errno} as a
``modifiable lvalue'' rather than as a variable, permitting it to be
implemented as a macro. For example, its expansion might involve a
function call, like @w{@code{*_errno ()}}. In fact, that is what it is
@end deftypevr
@comment errno.h
-@comment ANSI: Numerical argument out of domain
+@comment ISO: Numerical argument out of domain
@deftypevr Macro int EDOM
@comment errno 33 @c DO NOT REMOVE
Domain error; used by mathematical functions when an argument value does
@end deftypevr
@comment errno.h
-@comment ANSI: Numerical result out of range
+@comment ISO: Numerical result out of range
@deftypevr Macro int ERANGE
@comment errno 34 @c DO NOT REMOVE
Range error; used by mathematical functions when the result value is
name of the program that encountered the error.
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strerror (int @var{errnum})
The @code{strerror} function maps the error code (@pxref{Checking for
Errors}) specified by the @var{errnum} argument to a descriptive error
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun void perror (const char *@var{message})
This function prints an error message to the stream @code{stderr};
see @ref{Standard Streams}.
letter and does not include any terminating punctuation.
@strong{Compatibility Note:} The @code{strerror} function is a new
-feature of ANSI C. Many older C systems do not support this function
+feature of @w{ISO C}. Many older C systems do not support this function
yet.
@cindex program name
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int remove (const char *@var{filename})
-This is the ANSI C function to remove a file. It works like
+This is the @w{ISO C} function to remove a file. It works like
@code{unlink} for files and like @code{rmdir} for directories.
@code{remove} is declared in @file{stdio.h}.
@pindex stdio.h
@cindex renaming a file
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int rename (const char *@var{oldname}, const char *@var{newname})
The @code{rename} function renames the file name @var{oldname} with
@var{newname}. The file formerly accessible under the name
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {FILE *} tmpfile (void)
This function creates a temporary binary file for update mode, as if by
calling @code{fopen} with mode @code{"wb+"}. The file is deleted
automatically when it is closed or when the program terminates. (On
-some other ANSI C systems the file may fail to be deleted if the program
+some other @w{ISO C} systems the file may fail to be deleted if the program
terminates abnormally).
This function is reentrant.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} tmpnam (char *@var{result})
This function constructs and returns a file name that is a valid file
name and that does not name any existing file. If the @var{result}
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int L_tmpnam
The value of this macro is an integer constant expression that represents
the minimum allocation size of a string large enough to hold the
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int TMP_MAX
The macro @code{TMP_MAX} is a lower bound for how many temporary names
you can create with @code{tmpnam}. You can rely on being able to call
@cindex library
The GNU C library, described in this document, defines all of the
-library functions that are specified by the ANSI C standard, as well as
+library functions that are specified by the @w{ISO C} standard, as well as
additional features specific to POSIX and other derivatives of the Unix
operating system, and extensions specific to the GNU system.
This manual is written with the assumption that you are at least
somewhat familiar with the C programming language and basic programming
-concepts. Specifically, familiarity with ANSI standard C
-(@pxref{ANSI C}), rather than ``traditional'' pre-ANSI C dialects, is
+concepts. Specifically, familiarity with ISO standard C
+(@pxref{ISO C}), rather than ``traditional'' pre-ISO C dialects, is
assumed.
The GNU C library includes several @dfn{header files}, each of which
@cindex standards
This section discusses the various standards and other sources that the
-GNU C library is based upon. These sources include the ANSI C and
+GNU C library is based upon. These sources include the @w{ISO C} and
POSIX standards, and the System V and Berkeley Unix implementations.
The primary focus of this manual is to tell you how to make effective
standards each function or symbol comes from.
@menu
-* ANSI C:: The American National Standard for the
- C programming language.
-* POSIX:: The IEEE 1003 standards for operating
- systems.
+* ISO C:: The international standard for the C
+ programming language.
+* POSIX:: The ISO/IEC 9945 (aka IEEE 1003) standards
+ for operating systems.
* Berkeley Unix:: BSD and SunOS.
* SVID:: The System V Interface Description.
@end menu
-@node ANSI C, POSIX, , Standards and Portability
-@subsection ANSI C
-@cindex ANSI C
+@node ISO C, POSIX, , Standards and Portability
+@subsection ISO C
+@cindex ISO C
The GNU C library is compatible with the C standard adopted by the
American National Standards Institute (ANSI):
-@cite{American National Standard X3.159-1989---``ANSI C''}.
+@cite{American National Standard X3.159-1989---``ANSI C''} and later
+by the International Standardization Organizaion (ISO):
+@cite{ISO/IEC 9899:1990, ``Programming languages---C''}.
+We here refer to the standard as @w{ISO C} since this is the more
+general standard in respect of ratification.
The header files and library facilities that make up the GNU library are
-a superset of those specified by the ANSI C standard.@refill
+a superset of those specified by the @w{ISO C} standard.@refill
@pindex gcc
-If you are concerned about strict adherence to the ANSI C standard, you
+If you are concerned about strict adherence to the @w{ISO C} standard, you
should use the @samp{-ansi} option when you compile your programs with
-the GNU C compiler. This tells the compiler to define @emph{only} ANSI
+the GNU C compiler. This tells the compiler to define @emph{only} ISO
standard features from the library header files, unless you explicitly
ask for additional features. @xref{Feature Test Macros}, for
information on how to do this.
-Being able to restrict the library to include only ANSI C features is
-important because ANSI C puts limitations on what names can be defined
+Being able to restrict the library to include only @w{ISO C} features is
+important because @w{ISO C} puts limitations on what names can be defined
by the library implementation, and the GNU extensions don't fit these
limitations. @xref{Reserved Names}, for more information about these
restrictions.
This manual does not attempt to give you complete details on the
-differences between ANSI C and older dialects. It gives advice on how
+differences between @w{ISO C} and older dialects. It gives advice on how
to write programs to work portably under multiple C dialects, but does
not aim for completeness.
-@node POSIX, Berkeley Unix, ANSI C, Standards and Portability
+@node POSIX, Berkeley Unix, ISO C, Standards and Portability
@subsection POSIX (The Portable Operating System Interface)
@cindex POSIX
@cindex POSIX.1
various versions of the Unix operating system.
The library facilities specified by the POSIX standards are a superset
-of those required by ANSI C; POSIX specifies additional features for
-ANSI C functions, as well as specifying new additional functions. In
+of those required by @w{ISO C}; POSIX specifies additional features for
+@w{ISO C} functions, as well as specifying new additional functions. In
general, the additional requirements and functionality defined by the
POSIX standards are aimed at providing lower-level support for a
particular kind of operating system environment, rather than general
The GNU C library implements all of the functions specified in
@cite{IEEE Std 1003.1-1990, the POSIX System Application Program
Interface}, commonly referred to as POSIX.1. The primary extensions to
-the ANSI C facilities specified by this standard include file system
+the @w{ISO C} facilities specified by this standard include file system
interface primitives (@pxref{File System Interface}), device-specific
terminal control functions (@pxref{Low-Level Terminal Interface}), and
process control functions (@pxref{Processes}).
are not formally standardized, specifically from the 4.2 BSD, 4.3 BSD,
and 4.4 BSD Unix systems (also known as @dfn{Berkeley Unix}) and from
@dfn{SunOS} (a popular 4.2 BSD derivative that includes some Unix System
-V functionality). These systems support most of the ANSI and POSIX
+V functionality). These systems support most of the @w{ISO C} and POSIX
facilities, and 4.4 BSD and newer releases of SunOS in fact support them all.
The BSD facilities include symbolic links (@pxref{Symbolic Links}), the
superset of the POSIX standard (@pxref{POSIX}).
The GNU C library defines some of the facilities required by the SVID
-that are not also required by the ANSI or POSIX standards, for
+that are not also required by the @w{ISO C} or POSIX standards, for
compatibility with System V Unix and other Unix systems (such as
SunOS) which include these facilities. However, many of the more
obscure and less generally useful facilities required by the SVID are
are included doesn't matter.
@strong{Compatibility Note:} Inclusion of standard header files in any
-order and any number of times works in any ANSI C implementation.
+order and any number of times works in any @w{ISO C} implementation.
However, this has traditionally not been the case in many older C
implementations.
@cindex name space
The names of all library types, macros, variables and functions that
-come from the ANSI C standard are reserved unconditionally; your program
+come from the @w{ISO C} standard are reserved unconditionally; your program
@strong{may not} redefine these names. All other library names are
reserved if your program explicitly includes the header file that
defines or declares them. There are several reasons for these
If you are concerned about portability of your programs to systems other
than GNU, you should also be aware that file descriptors are not as
-portable as streams. You can expect any system running ANSI C to
+portable as streams. You can expect any system running @w{ISO C} to
support streams, but non-GNU systems may not support file descriptors at
all, or may only implement a subset of the GNU functions that operate on
file descriptors. Most of the file descriptor functions in the GNU
library are included in the POSIX.1 standard, however.
@node File Position, , Streams and File Descriptors, I/O Concepts
-@subsection File Position
+@subsection File Position
One of the attributes of an open file is its @dfn{file position} that
keeps track of where in the file the next character is to be read or
read the file at its own pace, each program must have its own file
pointer, which is not affected by anything the other programs do.
-In fact, each opening of a file creates a separate file position.
+In fact, each opening of a file creates a separate file position.
Thus, if you open a file twice even in the same program, you get two
streams or descriptors with independent file positions.
-By contrast, if you open a descriptor and then duplicate it to get
+By contrast, if you open a descriptor and then duplicate it to get
another descriptor, these two descriptors share the same file position:
changing the file position of one descriptor will affect the other.
The file named @file{a}, in the current working directory.
@item /a/./b
-This is the same as @file{/a/b}.
+This is the same as @file{/a/b}.
@item ./a
The file named @file{a}, in the current working directory.
directory.
@end table
-@c An empty string may ``work'', but I think it's confusing to
+@c An empty string may ``work'', but I think it's confusing to
@c try to describe it. It's not a useful thing for users to use--rms.
A file name that names a directory may optionally end in a @samp{/}.
You can specify a file name of @file{/} to refer to the root directory,
@table @code
@item EACCES
-The process does not have search permission for a directory component
+The process does not have search permission for a directory component
of the file name.
@item ENAMETOOLONG
file name portability issues:
@itemize @bullet
-@item
+@item
If your program makes assumptions about file name syntax, or contains
embedded literal file name strings, it is more difficult to get it to
run under other operating systems that use different syntax conventions.
by other operating systems.
@end itemize
-The ANSI C standard says very little about file name syntax, only that
+The @w{ISO C} standard says very little about file name syntax, only that
file names are strings. In addition to varying restrictions on the
length of file names and what characters can validly appear in a file
name, different operating systems use different conventions and syntax
about these restrictions; any character except the null character is
permitted in a file name string, and there are no limits on the length
of file name strings.
-
-
without indicating anything might be wrong.
@comment assert.h
-@comment ANSI
+@comment ISO
@deftypefn Macro void assert (int @var{expression})
Verify the programmer's belief that @var{expression} should be nonzero
at this point in the program.
@cindex variadic functions
@cindex optional arguments
-ANSI C defines a syntax for declaring a function to take a variable
+@w{ISO C} defines a syntax for declaring a function to take a variable
number or type of arguments. (Such functions are referred to as
@dfn{varargs functions} or @dfn{variadic functions}.) However, the
language itself provides no mechanism for such functions to access their
handle as many arguments as the caller chooses to pass.
Some functions such as @code{open} take a fixed set of arguments, but
-occasionally ignore the last few. Strict adherence to ANSI C requires
+occasionally ignore the last few. Strict adherence to @w{ISO C} requires
these functions to be defined as variadic; in practice, however, the GNU
C compiler and most other C compilers let you define such a function to
take a fixed set of arguments---the most it can ever use---and then only
variable arguments functions.
* Argument Macros:: Detailed specification of the macros
for accessing variable arguments.
-* Old Varargs:: The pre-ANSI way of defining variadic functions.
+* Old Varargs:: The pre-ISO way of defining variadic functions.
@end menu
@node Variadic Prototypes
A function that accepts a variable number of arguments must be declared
with a prototype that says so. You write the fixed arguments as usual,
and then tack on @samp{@dots{}} to indicate the possibility of
-additional arguments. The syntax of ANSI C requires at least one fixed
+additional arguments. The syntax of @w{ISO C} requires at least one fixed
argument before the @samp{@dots{}}. For example,
@smallexample
@dfn{self-promoting}: that is, the default promotions must not change
its type. This rules out array and function types, as well as
@code{float}, @code{char} (whether signed or not) and @w{@code{short int}}
-(whether signed or not). This is actually an ANSI C requirement.
+(whether signed or not). This is actually an @w{ISO C} requirement.
@node Receiving Arguments
@subsubsection Receiving the Argument Values
argument pointer value to a subroutine, you must not keep using the same
argument pointer value after that subroutine returns. For full
portability, you should just pass it to @code{va_end}. This is actually
-an ANSI C requirement, but most ANSI C compilers work happily
+an @w{ISO C} requirement, but most ANSI C compilers work happily
regardless.
@node How Many Arguments
@pindex stdarg.h
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} va_list
The type @code{va_list} is used for argument pointer variables.
@end deftp
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} void va_start (va_list @var{ap}, @var{last-required})
This macro initializes the argument pointer variable @var{ap} to point
to the first of the optional arguments of the current function;
@end deftypefn
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} @var{type} va_arg (va_list @var{ap}, @var{type})
The @code{va_arg} macro returns the value of the next optional argument,
and modifies the value of @var{ap} to point to the subsequent argument.
@end deftypefn
@comment stdarg.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} void va_end (va_list @var{ap})
This ends the use of @var{ap}. After a @code{va_end} call, further
@code{va_arg} calls with the same @var{ap} may not work. You should invoke
@subsubsection Old-Style Variadic Functions
@pindex varargs.h
-Before ANSI C, programmers used a slightly different facility for
+Before @w{ISO C}, programmers used a slightly different facility for
writing variadic functions. The GNU C compiler still supports it;
-currently, it is more portable than the ANSI C facility, since support
-for ANSI C is still not universal. The header file which defines the
+currently, it is more portable than the @w{ISO C} facility, since support
+for @w{ISO C} is still not universal. The header file which defines the
old-fashioned variadic facility is called @file{varargs.h}.
Using @file{varargs.h} is almost the same as using @file{stdarg.h}.
@code{NULL}.
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftypevr Macro {void *} NULL
This is a null pointer constant.
@end deftypevr
The result of subtracting two pointers in C is always an integer, but the
precise data type varies from C compiler to C compiler. Likewise, the
data type of the result of @code{sizeof} also varies between compilers.
-ANSI defines standard aliases for these two types, so you can refer to
+ISO defines standard aliases for these two types, so you can refer to
them in a portable fashion. They are defined in the header file
@file{stddef.h}.
@pindex stddef.h
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} ptrdiff_t
This is the signed integer type of the result of subtracting two
pointers. For example, with the declaration @code{char *p1, *p2;}, the
@end deftp
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} size_t
This is an unsigned integer type used to represent the sizes of objects.
The result of the @code{sizeof} operator is of this type, and functions
have type @code{size_t}, never declare its type in any other way.
@strong{Compatibility Note:} Implementations of C before the advent of
-ANSI C generally used @code{unsigned int} for representing object sizes
+@w{ISO C} generally used @code{unsigned int} for representing object sizes
and @code{int} for pointer subtraction results. They did not
necessarily define either @code{size_t} or @code{ptrdiff_t}. Unix
systems did define @code{size_t}, in @file{sys/types.h}, but the
@table @code
@comment limits.h
-@comment ANSI
+@comment ISO
@item CHAR_BIT
This is the number of bits in a @code{char}---eight, on most systems.
The value has type @code{int}.
@comment Extra blank lines make it look better.
@table @code
@comment limits.h
-@comment ANSI
+@comment ISO
@item SCHAR_MIN
This is the minimum value that can be represented by a @w{@code{signed char}}.
@comment limits.h
-@comment ANSI
+@comment ISO
@item SCHAR_MAX
@comment limits.h
-@comment ANSI
+@comment ISO
@itemx UCHAR_MAX
These are the maximum values that can be represented by a
@w{@code{signed char}} and @w{@code{unsigned char}}, respectively.
@comment limits.h
-@comment ANSI
+@comment ISO
@item CHAR_MIN
This is the minimum value that can be represented by a @code{char}.
otherwise.
@comment limits.h
-@comment ANSI
+@comment ISO
@item CHAR_MAX
This is the maximum value that can be represented by a @code{char}.
@code{UCHAR_MAX} otherwise.
@comment limits.h
-@comment ANSI
+@comment ISO
@item SHRT_MIN
This is the minimum value that can be represented by a @w{@code{signed
@code{short} integers are 16-bit quantities.
@comment limits.h
-@comment ANSI
+@comment ISO
@item SHRT_MAX
@comment limits.h
-@comment ANSI
+@comment ISO
@itemx USHRT_MAX
These are the maximum values that can be represented by a
respectively.
@comment limits.h
-@comment ANSI
+@comment ISO
@item INT_MIN
This is the minimum value that can be represented by a @w{@code{signed
a 32-bit quantity.
@comment limits.h
-@comment ANSI
+@comment ISO
@item INT_MAX
@comment limits.h
-@comment ANSI
+@comment ISO
@itemx UINT_MAX
These are the maximum values that can be represented by, respectively,
the type @w{@code{signed int}} and the type @w{@code{unsigned int}}.
@comment limits.h
-@comment ANSI
+@comment ISO
@item LONG_MIN
This is the minimum value that can be represented by a @w{@code{signed
integers are 32-bit quantities, the same size as @code{int}.
@comment limits.h
-@comment ANSI
+@comment ISO
@item LONG_MAX
@comment limits.h
-@comment ANSI
+@comment ISO
@itemx ULONG_MAX
These are the maximum values that can be represented by a
@comment GNU
@item LONG_LONG_MAX
@comment limits.h
-@comment ANSI
+@comment ISO
@itemx ULONG_LONG_MAX
These are the maximum values that can be represented by a @code{signed
places that require constant expressions, such as @samp{#if}
preprocessing directives or in the dimensions of static arrays.
-Although the ANSI C standard specifies minimum and maximum values for
+Although the @w{ISO C} standard specifies minimum and maximum values for
most of these parameters, the GNU C implementation uses whatever values
describe the floating point representation of the target machine. So in
-principle GNU C actually satisfies the ANSI C requirements only if the
+principle GNU C actually satisfies the @w{ISO C} requirements only if the
target machine is suitable. In practice, all the machines currently
supported are suitable.
@table @code
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_ROUNDS
This value characterizes the rounding mode for floating point addition.
The following values indicate standard rounding modes:
@end smallexample
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_RADIX
This is the value of the base, or radix, of exponent representation.
This is guaranteed to be a constant expression, unlike the other macros
except the IBM 360 and derivatives.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating point
mantissa for the @code{float} data type. The following expression
where @code{radix} appears @code{FLT_MANT_DIG} times.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MANT_DIG
@itemx LDBL_MANT_DIG
This is the number of base-@code{FLT_RADIX} digits in the floating point
@comment Extra blank lines make it look better.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_DIG
This is the number of decimal digits of precision for the @code{float}
change to the @var{q} decimal digits.
The value of this macro is supposed to be at least @code{6}, to satisfy
-ANSI C.
+@w{ISO C}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_DIG
@itemx LDBL_DIG
macros are supposed to be at least @code{10}.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MIN_EXP
This is the smallest possible exponent value for type @code{float}.
More precisely, is the minimum negative integer such that the value
normalized floating point number of type @code{float}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MIN_EXP
@itemx LDBL_MIN_EXP
@code{double} and @code{long double}, respectively.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MIN_10_EXP
This is the minimum negative integer such that @code{10} raised to this
power minus 1 can be represented as a normalized floating point number
of type @code{float}. This is supposed to be @code{-37} or even less.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MIN_10_EXP
@itemx LDBL_MIN_10_EXP
These are similar to @code{FLT_MIN_10_EXP}, but for the data types
@code{double} and @code{long double}, respectively.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MAX_EXP
This is the largest possible exponent value for type @code{float}. More
precisely, this is the maximum positive integer such that value
floating point number of type @code{float}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MAX_EXP
@itemx LDBL_MAX_EXP
These are similar to @code{FLT_MAX_EXP}, but for the data types
@code{double} and @code{long double}, respectively.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MAX_10_EXP
This is the maximum positive integer such that @code{10} raised to this
power minus 1 can be represented as a normalized floating point number
of type @code{float}. This is supposed to be at least @code{37}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MAX_10_EXP
@itemx LDBL_MAX_10_EXP
These are similar to @code{FLT_MAX_10_EXP}, but for the data types
@code{double} and @code{long double}, respectively.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MAX
The value of this macro is the maximum number representable in type
The smallest representable number is @code{- FLT_MAX}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MAX
@itemx LDBL_MAX
macro's value is the same as the type it describes.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_MIN
The value of this macro is the minimum normalized positive floating
to be no more than @code{1E-37}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_MIN
@itemx LDBL_MIN
macro's value is the same as the type it describes.
@comment float.h
-@comment ANSI
+@comment ISO
@item FLT_EPSILON
This is the minimum positive floating point number of type @code{float}
be no greater than @code{1E-5}.
@comment float.h
-@comment ANSI
+@comment ISO
@item DBL_EPSILON
@itemx LDBL_EPSILON
type of a particular structure member.
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftypefn {Macro} size_t offsetof (@var{type}, @var{member})
This expands to a integer constant expression that is the offset of the
structure member named @var{member} in a the structure type @var{type}.
Standards and Portability
-* ANSI C:: The American National Standard for the
+* ISO C:: The American National Standard for the
C programming language.
-* POSIX:: The IEEE 1003 standards for operating systems.
+* POSIX:: The ISO/IEC 9945 (aka IEEE 1003) standards
+ for operating systems.
* Berkeley Unix:: BSD and SunOS.
* SVID:: The System V Interface Description.
* Binary Streams:: Some systems distinguish between text files
and binary files.
* File Positioning:: About random-access streams.
-* Portable Positioning:: Random access on peculiar ANSI C systems.
+* Portable Positioning:: Random access on peculiar ISO C systems.
* Stream Buffering:: How to control buffering of streams.
* Temporary Files:: How to open a temporary file.
* Other Kinds of Streams:: Other Kinds of Streams
Pseudo-Random Numbers
-* ANSI Random:: @code{rand} and friends.
+* ISO Random:: @code{rand} and friends.
* BSD Random:: @code{random} and friends.
Low-Level Arithmetic Functions
@cindex internationalization
@cindex locales
@dfn{Internationalization} of software means programming it to be able
-to adapt to the user's favorite conventions. In ANSI C,
+to adapt to the user's favorite conventions. In @w{ISO C},
internationalization works by means of @dfn{locales}. Each locale
specifies a collection of conventions, one convention for each purpose.
The user chooses a set of conventions by specifying a locale (via
@menu
* Effects of Locale:: Actions affected by the choice of
- locale.
+ locale.
* Choosing Locale:: How the user specifies a locale.
* Locale Categories:: Different purposes for which you can
- select a locale.
+ select a locale.
* Setting the Locale:: How a program specifies the locale
- with library functions.
+ with library functions.
* Standard Locales:: Locale names available on all systems.
* Numeric Formatting:: How to format numbers according to the
- chosen locale.
+ chosen locale.
@end menu
@node Effects of Locale, Choosing Locale, , Locales
@table @code
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_COLLATE
@vindex LC_COLLATE
This category applies to collation of strings (functions @code{strcoll}
and @code{strxfrm}); see @ref{Collation Functions}.
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_CTYPE
@vindex LC_CTYPE
This category applies to classification and conversion of characters,
see @ref{Character Handling} and @ref{Extended Characters}.
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_MONETARY
@vindex LC_MONETARY
This category applies to formatting monetary values; see @ref{Numeric
Formatting}.
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_NUMERIC
@vindex LC_NUMERIC
This category applies to formatting numeric values that are not
monetary; see @ref{Numeric Formatting}.
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_TIME
@vindex LC_TIME
This category applies to formatting date and time values; see
@ref{Formatting Date and Time}.
-@ignore This is apparently a feature that was in some early
-draft of the POSIX.2 standard, but it's not listed in draft 11. Do we
-still support this anyway? Is there a corresponding environment
-variable?
-
@comment locale.h
-@comment GNU
-@item LC_RESPONSE
-@vindex LC_RESPONSE
-This category applies to recognizing ``yes'' or ``no'' responses to
-questions.
+@comment XOPEN
+@item LC_MESSAGES
+@vindex LC_MESSAGES
+This category applies to selecting the language used in the user interface
+for message translation.
+@ignore see @ref{gettext} and @ref{catgets}
@end ignore
@comment locale.h
-@comment ANSI
+@comment ISO
@item LC_ALL
@vindex LC_ALL
This is not an environment variable; it is only a macro that you can use
with @code{setlocale} to set a single locale for all purposes.
@comment locale.h
-@comment ANSI
+@comment ISO
@item LANG
@vindex LANG
If this environment variable is defined, its value specifies the locale
A C program inherits its locale environment variables when it starts up.
This happens automatically. However, these variables do not
automatically control the locale used by the library functions, because
-ANSI C says that all programs start by default in the standard @samp{C}
+@w{ISO C} says that all programs start by default in the standard @samp{C}
locale. To use the locales specified by the environment, you must call
@code{setlocale}. Call it as follows:
The symbols in this section are defined in the header file @file{locale.h}.
@comment locale.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} setlocale (int @var{category}, const char *@var{locale})
-The function @code{setlocale} sets the current locale for
+The function @code{setlocale} sets the current locale for
category @var{category} to @var{locale}.
If @var{category} is @code{LC_ALL}, this specifies the locale for all
@code{setlocale} itself.)
You should not modify the string returned by @code{setlocale}.
-It might be the same string that was passed as an argument in a
+It might be the same string that was passed as an argument in a
previous call to @code{setlocale}.
When you read the current locale for category @code{LC_ALL}, the value
/* @r{Get the name of the current locale.} */
old_locale = setlocale (LC_ALL, NULL);
-
+
/* @r{Copy the name so it won't be clobbered by @code{setlocale}.} */
saved_locale = strdup (old_locale);
if (old_locale == NULL)
fatal ("Out of memory");
-
+
/* @r{Now change the locale and do some stuff with it.} */
setlocale (LC_ALL, new_locale);
(*subroutine) (argument);
-
+
/* @r{Restore the original locale.} */
setlocale (LC_ALL, saved_locale);
free (saved_locale);
@}
@end smallexample
-@strong{Portability Note:} Some ANSI C systems may define additional
+@strong{Portability Note:} Some @w{ISO C} systems may define additional
locale categories. For portability, assume that any symbol beginning
with @samp{LC_} might be defined in @file{locale.h}.
@table @code
@item "C"
This is the standard C locale. The attributes and behavior it provides
-are specified in the ANSI C standard. When your program starts up, it
+are specified in the @w{ISO C} standard. When your program starts up, it
initially uses this locale by default.
@item "POSIX"
@cindex numeric value formatting
@comment locale.h
-@comment ANSI
+@comment ISO
@deftypefun {struct lconv *} localeconv (void)
The @code{localeconv} function returns a pointer to a structure whose
components contain information about how numeric and monetary values
@end deftypefun
@comment locale.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} {struct lconv}
This is the data type of the value returned by @code{localeconv}.
@end deftp
members have the same value.)
In the standard @samp{C} locale, both of these members have the value
-@code{CHAR_MAX}, meaning ``unspecified''. The ANSI standard doesn't say
+@code{CHAR_MAX}, meaning ``unspecified''. The ISO standard doesn't say
what to do when you find this the value; we recommend printing no
fractional digits. (This locale also specifies the empty string for
@code{mon_decimal_point}, so printing any fractional digits would be
The local currency symbol for the selected locale.
In the standard @samp{C} locale, this member has a value of @code{""}
-(the empty string), meaning ``unspecified''. The ANSI standard doesn't
+(the empty string), meaning ``unspecified''. The ISO standard doesn't
say what to do when you find this value; we recommend you simply print
the empty string as you would print any other string found in the
appropriate member.
negative amounts.
In the standard @samp{C} locale, both of these members have a value of
-@code{CHAR_MAX}, meaning ``unspecified''. The ANSI standard doesn't say
+@code{CHAR_MAX}, meaning ``unspecified''. The ISO standard doesn't say
what to do when you find this value, but we recommend printing the
currency symbol before the amount. That's right for most countries.
In other words, treat all nonzero values alike in these members.
The POSIX standard says that these two members apply to the
-@code{int_curr_symbol} as well as the @code{currency_symbol}. The ANSI
+@code{int_curr_symbol} as well as the @code{currency_symbol}. The ISO
C standard seems to imply that they should apply only to the
@code{currency_symbol}---so the @code{int_curr_symbol} should always
precede the amount.
negative amounts.
In the standard @samp{C} locale, both of these members have a value of
-@code{CHAR_MAX}, meaning ``unspecified''. The ANSI standard doesn't say
+@code{CHAR_MAX}, meaning ``unspecified''. The ISO standard doesn't say
what you should do when you find this value; we suggest you treat it as
one (print a space). In other words, treat all nonzero values alike in
these members.
The POSIX standard says that these two members apply to the
@code{int_curr_symbol} as well as the @code{currency_symbol}. But an
-example in the ANSI C standard clearly implies that they should apply
+example in the @w{ISO C} standard clearly implies that they should apply
only to the @code{currency_symbol}---that the @code{int_curr_symbol}
contains any appropriate separator, so you should never print an
additional space.
In the standard @samp{C} locale, both of these members have a value of
@code{""} (the empty string), meaning ``unspecified''.
-The ANSI standard doesn't say what to do when you find this value; we
+The ISO standard doesn't say what to do when you find this value; we
recommend printing @code{positive_sign} as you find it, even if it is
empty. For a negative value, print @code{negative_sign} as you find it
unless both it and @code{positive_sign} are empty, in which case print
@samp{C} locale.
@end table
-The ANSI standard doesn't say what you should do when the value is
+The ISO standard doesn't say what you should do when the value is
@code{CHAR_MAX}. We recommend you print the sign after the currency
symbol.
@end table
It is not clear whether you should let these members apply to the
international currency format or not. POSIX says you should, but
-intuition plus the examples in the ANSI C standard suggest you should
+intuition plus the examples in the @w{ISO C} standard suggest you should
not. We hope that someone who knows well the conventions for formatting
monetary quantities will tell us what we should recommend.
-
you ran @file{configure}.
If you think you have found some way in which the GNU C library does not
-conform to the ANSI and POSIX standards (@pxref{Standards and
+conform to the ISO and POSIX standards (@pxref{Standards and
Portability}), that is definitely a bug. Report it!@refill
Send bug reports to the Internet address
@c ??? This section is really short now. Want to keep it? --roland
-Although the GNU C library implements the ANSI C library facilities, you
-@emph{can} use the GNU C library with traditional, ``pre-ANSI'' C
+Although the GNU C library implements the @w{ISO C} library facilities, you
+@emph{can} use the GNU C library with traditional, ``pre-ISO'' C
compilers. However, you need to be careful because the content and
organization of the GNU C library header files differs from that of
traditional C implementations. This means you may need to make changes
@code{rand} and @code{srand} functions, were written by Earl T. Cohen
for the University of California at Berkeley and are copyrighted by the
Regents of the University of California. They have undergone minor
-changes to fit into the GNU C library and to fit the ANSI C standard,
+changes to fit into the GNU C library and to fit the @w{ISO C} standard,
but the functional code is Berkeley's.@refill
@item
Handling}, for more information about signals.)
@comment math.h
-@comment ANSI
+@comment ISO
@deftypevr Macro double HUGE_VAL
An expression representing a particular very large number. On machines
-that use @w{IEEE 754} floating point format, the value is ``infinity''.
-On other machines, it's typically the largest positive number that can
-be represented.
+that use @w{IEEE 754}/@w{IEEE 854} floating point format, the value is
+``infinity''. On other machines, it's typically the largest positive
+number that can be represented.
The value of this macro is used as the return value from various
mathematical @code{double} returning functions in overflow situations.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double sin (double @var{x})
This function returns the sine of @var{x}, where @var{x} is given in
radians. The return value is in the range @code{-1} to @code{1}.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double cos (double @var{x})
This function returns the cosine of @var{x}, where @var{x} is given in
radians. The return value is in the range @code{-1} to @code{1}.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double tan (double @var{x})
This function returns the tangent of @var{x}, where @var{x} is given in
radians.
respectively.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double asin (double @var{x})
This function computes the arc sine of @var{x}---that is, the value whose
sine is @var{x}. The value is in units of radians. Mathematically,
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double acos (double @var{x})
This function computes the arc cosine of @var{x}---that is, the value
whose cosine is @var{x}. The value is in units of radians.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double atan (double @var{x})
This function computes the arc tangent of @var{x}---that is, the value
whose tangent is @var{x}. The value is in units of radians.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double atan2 (double @var{y}, double @var{x})
This is the two argument arc tangent function. It is similar to computing
the arc tangent of @var{y}/@var{x}, except that the signs of both arguments
@cindex logarithm functions
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double exp (double @var{x})
The @code{exp} function returns the value of e (the base of natural
logarithms) raised to power @var{x}.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double log (double @var{x})
This function returns the natural logarithm of @var{x}. @code{exp (log
(@var{x}))} equals @var{x}, exactly in mathematics and approximately in
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double log10 (double @var{x})
This function returns the base-10 logarithm of @var{x}. Except for the
different base, it is similar to the @code{log} function. In fact,
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double pow (double @var{base}, double @var{power})
This is a general exponentiation function, returning @var{base} raised
to @var{power}.
@cindex square root function
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double sqrt (double @var{x})
This function returns the nonnegative square root of @var{x}.
see @ref{Exponents and Logarithms}.
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double sinh (double @var{x})
The @code{sinh} function returns the hyperbolic sine of @var{x}, defined
mathematically as @w{@code{exp (@var{x}) - exp (-@var{x}) / 2}}. The
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double cosh (double @var{x})
The @code{cosh} function returns the hyperbolic cosine of @var{x},
defined mathematically as @w{@code{exp (@var{x}) + exp (-@var{x}) / 2}}.
@end deftypefun
@comment math.h
-@comment ANSI
+@comment ISO
@deftypefun double tanh (double @var{x})
This function returns the hyperbolic tangent of @var{x}, whose
mathematical definition is @w{@code{sinh (@var{x}) / cosh (@var{x})}}.
the same seed, used in different C libraries or on different CPU types,
will give you different random numbers.
-The GNU library supports the standard ANSI C random number functions
+The GNU library supports the standard @w{ISO C} random number functions
plus another set derived from BSD. We recommend you use the standard
ones, @code{rand} and @code{srand}.
@menu
-* ANSI Random:: @code{rand} and friends.
+* ISO Random:: @code{rand} and friends.
* BSD Random:: @code{random} and friends.
@end menu
-@node ANSI Random
-@subsection ANSI C Random Number Functions
+@node ISO Random
+@subsection ISO C Random Number Functions
This section describes the random number functions that are part of
-the ANSI C standard.
+the @w{ISO C} standard.
To use these facilities, you should include the header file
@file{stdlib.h} in your program.
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int RAND_MAX
The value of this macro is an integer constant expression that
represents the maximum possible value returned by the @code{rand}
@end deftypevr
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int rand ()
The @code{rand} function returns the next pseudo-random number in the
series. The value is in the range from @code{0} to @code{RAND_MAX}.
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void srand (unsigned int @var{seed})
This function establishes @var{seed} as the seed for a new series of
pseudo-random numbers. If you call @code{rand} before a seed has been
and vice versa.
* Length of Char:: how many bytes make up one multibyte char.
* Converting One Char:: Converting a string character by character.
-* Example of Conversion:: Example showing why converting
+* Example of Conversion:: Example showing why converting
one character at a time may be useful.
* Shift State:: Multibyte codes with "shift characters".
@end menu
code supported on your computer with @code{MB_LEN_MAX}.
@comment limits.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int MB_LEN_MAX
This is the maximum length of a multibyte character for any supported
locale. It is defined in @file{limits.h}.
@end deftypevr
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int MB_CUR_MAX
This macro expands into a (possibly non-constant) positive integer
expression that is the maximum number of bytes in a multibyte character
byte with value zero often terminates a string of ordinary characters.
@comment stddef.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} wchar_t
This is the ``wide character'' type, an integer type whose range is
large enough to represent all distinct values in any extended character
Char}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun size_t mbstowcs (wchar_t *@var{wstring}, const char *@var{string}, size_t @var{size})
The @code{mbstowcs} (``multibyte string to wide character string'')
function converts the null-terminated string of multibyte characters
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun size_t wcstombs (char *@var{string}, const wchar_t @var{wstring}, size_t @var{size})
The @code{wcstombs} (``wide character string to multibyte string'')
function converts the null-terminated wide character array @var{wstring}
This section describes how to scan a string containing multibyte
characters, one character at a time. The difficulty in doing this
-is to know how many bytes each character contains. Your program
+is to know how many bytes each character contains. Your program
can use @code{mblen} to find this out.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int mblen (const char *@var{string}, size_t @var{size})
The @code{mblen} function with a non-null @var{string} argument returns
the number of bytes that make up the multibyte character beginning at
reverse. These functions are declared in @file{stdlib.h}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int mbtowc (wchar_t *@var{result}, const char *@var{string}, size_t @var{size})
The @code{mbtowc} (``multibyte to wide character'') function when called
with non-null @var{string} converts the first multibyte character
@end deftypefun
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int wctomb (char *@var{string}, wchar_t @var{wchar})
The @code{wctomb} (``wide character to multibyte'') function converts
the wide character code @var{wchar} to its corresponding multibyte
@end deftypefun
@node Example of Conversion, Shift State, Converting One Char, Extended Characters
-@section Character-by-Character Conversion Example
+@section Character-by-Character Conversion Example
Here is an example that reads multibyte character text from descriptor
@code{input} and writes the corresponding wide characters to descriptor
@pindex stdlib.h
@comment malloc.h stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} malloc (size_t @var{size})
This function returns a pointer to a newly allocated block @var{size}
bytes long, or a null pointer if the block could not be allocated.
@end smallexample
You can store the result of @code{malloc} into any pointer variable
-without a cast, because ANSI C automatically converts the type
+without a cast, because @w{ISO C} automatically converts the type
@code{void *} to another type of pointer when necessary. But the cast
is necessary in contexts other than assignment operators or if you might
want your code to run in traditional C.
@pindex stdlib.h
@comment malloc.h stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void free (void *@var{ptr})
The @code{free} function deallocates the block of storage pointed at
by @var{ptr}.
@pindex stdlib.h
@comment malloc.h stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} realloc (void *@var{ptr}, size_t @var{newsize})
The @code{realloc} function changes the size of the block whose address is
@var{ptr} to be @var{newsize}.
If you pass a null pointer for @var{ptr}, @code{realloc} behaves just
like @samp{malloc (@var{newsize})}. This can be convenient, but beware
-that older implementations (before ANSI C) may not support this
+that older implementations (before @w{ISO C}) may not support this
behavior, and will probably crash when @code{realloc} is passed a null
pointer.
@end deftypefun
@pindex stdlib.h
@comment malloc.h stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} calloc (size_t @var{count}, size_t @var{eltsize})
This function allocates a block long enough to contain a vector of
@var{count} elements, each of size @var{eltsize}. Its contents are
The interfaces for using obstacks may be defined either as functions or
as macros, depending on the compiler. The obstack facility works with
-all C compilers, including both ANSI C and traditional C, but there are
+all C compilers, including both @w{ISO C} and traditional C, but there are
precautions you must take if you plan to use compilers other than GNU C.
-If you are using an old-fashioned non-ANSI C compiler, all the obstack
+If you are using an old-fashioned @w{non-ISO C} compiler, all the obstack
``functions'' are actually defined only as macros. You can call these
macros like functions, but you cannot use them in any other way (for
example, you cannot take their address).
you will get very strange results since the incrementation may occur
several times.
-In ANSI C, each function has both a macro definition and a function
+In @w{ISO C}, each function has both a macro definition and a function
definition. The function definition is used if you take the address of the
function without calling it. An ordinary call uses the macro definition by
default, but you can request the function definition instead by writing the
@end smallexample
@noindent
-This is the same situation that exists in ANSI C for the standard library
+This is the same situation that exists in @w{ISO C} for the standard library
functions. @xref{Macro Definitions}.
@strong{Warning:} When you do use the macros, you must observe the
-precaution of avoiding side effects in the first operand, even in ANSI
-C.
+precaution of avoiding side effects in the first operand, even in @w{ISO C}.
If you use the GNU C compiler, this precaution is not necessary, because
various language extensions in GNU C permit defining the macros so as to
* Creating a Process:: How to fork a child process.
* Executing a File:: How to make a process execute another program.
* Process Completion:: How to tell when a child process has completed.
-* Process Completion Status:: How to interpret the status value
+* Process Completion Status:: How to interpret the status value
returned from a child process.
* BSD Wait Functions:: More functions, for backward compatibility.
* Process Creation Example:: A complete example program.
until the subprogram terminates before you can do anything else.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int system (const char *@var{command})
@pindex sh
This function executes @var{command} as a shell command. In the GNU C
The set of pending signals (@pxref{Delivery of Signal}) for the child
process is cleared. (The child process inherits its mask of blocked
signals and signal actions from the parent process.)
-@end itemize
+@end itemize
@comment unistd.h
@deftypefun int execve (const char *@var{filename}, char *const @var{argv}@t{[]}, char *const @var{env}@t{[]})
This is similar to @code{execv}, but permits you to specify the environment
for the new program explicitly as the @var{env} argument. This should
-be an array of strings in the same format as for the @code{environ}
+be an array of strings in the same format as for the @code{environ}
variable; see @ref{Environment Access}.
@end deftypefun
#define SHELL "/bin/sh"
@group
-int
+int
my_system (const char *command)
@{
int status;
Remember that the first @code{argv} argument supplied to the program
represents the name of the program being executed. That is why, in the
call to @code{execl}, @code{SHELL} is supplied once to name the program
-to execute and a second time to supply a value for @code{argv[0]}.
+to execute and a second time to supply a value for @code{argv[0]}.
The @code{execl} call in the child process doesn't return if it is
successful. If it fails, you must do something to make the child
@node Searching and Sorting, Pattern Matching, Locales, Top
-@chapter Searching and Sorting
+@chapter Searching and Sorting
This chapter describes functions for searching and sorting arrays of
arbitrary objects. You pass the appropriate comparison function to be
* Comparison Functions:: Defining how to compare two objects.
Since the sort and search facilities
are general, you have to specify the
- ordering.
+ ordering.
* Array Search Function:: The @code{bsearch} function.
* Array Sort Function:: The @code{qsort} function.
* Search/Sort Example:: An example program.
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} bsearch (const void *@var{key}, const void *@var{array}, size_t @var{count}, size_t @var{size}, comparison_fn_t @var{compare})
The @code{bsearch} function searches the sorted array @var{array} for an object
that is equivalent to @var{key}. The array contains @var{count} elements,
-each of which is of size @var{size} bytes.
+each of which is of size @var{size} bytes.
The @var{compare} function is used to perform the comparison. This
function is called with two pointer arguments and should return an
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void qsort (void *@var{array}, size_t @var{count}, size_t @var{size}, comparison_fn_t @var{compare})
The @var{qsort} function sorts the array @var{array}. The array contains
@var{count} elements, each of which is of size @var{size}.
Gonzo, the whatever
Couldn't find Janice.
@end smallexample
-
-
@code{longjmp}, so calls to @code{setjmp} usually appear in an @samp{if}
statement.
-Here is how the example program described above might be set up:
+Here is how the example program described above might be set up:
@smallexample
@include setjmp.c.texi
@pindex setjmp.h
@comment setjmp.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} jmp_buf
Objects of type @code{jmp_buf} hold the state information to
be restored by a non-local exit. The contents of a @code{jmp_buf}
@end deftp
@comment setjmp.h
-@comment ANSI
+@comment ISO
@deftypefn Macro int setjmp (jmp_buf @var{state})
When called normally, @code{setjmp} stores information about the
execution state of the program in @var{state} and returns zero. If
@end deftypefn
@comment setjmp.h
-@comment ANSI
-@deftypefun void longjmp (jmp_buf @var{state}, int @var{value})
+@comment ISO
+@deftypefun void longjmp (jmp_buf @var{state}, int @var{value})
This function restores current execution to the state saved in
@var{state}, and continues execution from the call to @code{setjmp} that
established that return point. Returning from @code{setjmp} by means of
nonzero @var{savesigs} flag, @code{siglongjmp} also restores the set of
blocked signals.
@end deftypefun
-
* Generating Signals:: How to send a signal to a process.
* Blocking Signals:: Making the system hold signals temporarily.
* Waiting for a Signal:: Suspending your program until a signal
- arrives.
+ arrives.
* Signal Stack:: Using a Separate Signal Stack.
* BSD Signal Handling:: Additional functions for backward
compatibility with BSD.
* Kinds of Signals:: Some examples of what can cause a signal.
* Signal Generation:: Concepts of why and how signals occur.
* Delivery of Signal:: Concepts of what a signal does to the
- process.
+ process.
@end menu
@node Kinds of Signals
-@subsection Some Kinds of Signals
+@subsection Some Kinds of Signals
A signal reports the occurrence of an exceptional event. These are some
of the events that can cause (or @dfn{generate}, or @dfn{raise}) a
@menu
* Program Error Signals:: Used to report serious program errors.
* Termination Signals:: Used to interrupt and/or terminate the
- program.
+ program.
* Alarm Signals:: Used to indicate expiration of timers.
* Asynchronous I/O Signals:: Used to indicate input is available.
* Job Control Signals:: Signals used to support job control.
what caused the error.
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGFPE
The @code{SIGFPE} signal reports a fatal arithmetic error. Although the
name is derived from ``floating-point exception'', this signal actually
Actual floating-point exceptions are a complicated subject because there
are many types of exceptions with subtly different meanings, and the
@code{SIGFPE} signal doesn't distinguish between them. The @cite{IEEE
-Standard for Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985)}
+Standard for Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985
+and ANSI/IEEE Std 854-1987)}
defines various floating-point exceptions and requires conforming
computer systems to report their occurrences. However, this standard
does not specify how the exceptions are reported, or what kinds of
@end table
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGILL
The name of this signal is derived from ``illegal instruction''; it
usually means your program is trying to execute garbage or a privileged
@cindex illegal instruction
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGSEGV
@cindex segmentation violation
This signal is generated when a program tries to read or write outside
@cindex bus error
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGABRT
@cindex abort signal
This signal indicates an error detected by the program itself and
process to terminate.
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGTERM
@cindex termination signal
The @code{SIGTERM} signal is a generic signal used to cause program
@end deftypevr
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SIGINT
@cindex interrupt signal
The @code{SIGINT} (``program interrupt'') signal is sent when the user
@comment BSD
@deftypevr Macro int SIGPROF
This signal is typically indicates expiration of a timer that measures
-both CPU time used by the current process, and CPU time expended on
+both CPU time used by the current process, and CPU time expended on
behalf of the process by the system. Such a timer is used to implement
code profiling facilities, hence the name of this signal.
@end deftypevr
files that can generate @code{SIGIO}; other kinds, including ordinary
files, never generate @code{SIGIO} even if you ask them to.
-In the GNU system @code{SIGIO} will always be generated properly
+In the GNU system @code{SIGIO} will always be generated properly
if you successfully set asynchronous mode with @code{fcntl}.
@end deftypevr
@comment POSIX.1
@deftypevr Macro int SIGTSTP
The @code{SIGTSTP} signal is an interactive stop signal. Unlike
-@code{SIGSTOP}, this signal can be handled and ignored.
+@code{SIGSTOP}, this signal can be handled and ignored.
Your program should handle this signal if you have a special need to
leave files or system tables in a secure state when a process is
@comment signal.h
@comment POSIX.1
@deftypevr Macro int SIGTTIN
-A process cannot read from the the user's terminal while it is running
+A process cannot read from the the user's terminal while it is running
as a background job. When any process in a background job tries to
read from the terminal, all of the processes in the job are sent a
@code{SIGTTIN} signal. The default action for this signal is to
standard error output stream @code{stderr}; see @ref{Standard Streams}.
If you call @code{psignal} with a @var{message} that is either a null
-pointer or an empty string, @code{psignal} just prints the message
+pointer or an empty string, @code{psignal} just prints the message
corresponding to @var{signum}, adding a trailing newline.
If you supply a non-null @var{message} argument, then @code{psignal}
-prefixes its output with this string. It adds a colon and a space
+prefixes its output with this string. It adds a colon and a space
character to separate the @var{message} from the string corresponding
to @var{signum}.
@end deftp
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypefun sighandler_t signal (int @var{signum}, sighandler_t @var{action})
The @code{signal} function establishes @var{action} as the action for
the signal @var{signum}.
@end deftypefun
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypevr Macro sighandler_t SIG_ERR
The value of this macro is used as the return value from @code{signal}
to indicate an error.
handler, you must write code in the handler to unblock it.
@item int sa_flags
-This specifies various flags which can affect the behavior of
+This specifies various flags which can affect the behavior of
the signal. These are described in more detail in @ref{Flags for Sigaction}.
@end table
@end deftp
problem never happens on the GNU system.
So, you're better off using one or the other of the mechanisms
-consistently within a single program.
+consistently within a single program.
@strong{Portability Note:} The basic @code{signal} function is a feature
-of ANSI C, while @code{sigaction} is part of the POSIX.1 standard. If
+of @w{ISO C}, while @code{sigaction} is part of the POSIX.1 standard. If
you are concerned about portability to non-POSIX systems, then you
should use the @code{signal} function instead.
struct sigaction query_action;
if (sigaction (SIGINT, NULL, &query_action) < 0)
- /* @r{@code{sigaction} returns -1 in case of error.} */
+ /* @r{@code{sigaction} returns -1 in case of error.} */
else if (query_action.sa_handler == SIG_DFL)
/* @r{@code{SIGINT} is handled in the default, fatal manner.} */
else if (query_action.sa_handler == SIG_IGN)
@menu
* Handler Returns:: Handlers that return normally, and what
- this means.
+ this means.
* Termination in Handler:: How handler functions terminate a program.
* Longjmp in Handler:: Nonlocal transfer of control out of a
signal handler.
* Merged Signals:: When a second signal arrives before the
first is handled.
* Nonreentrancy:: Do not call any functions unless you know they
- are reentrant with respect to signals.
+ are reentrant with respect to signals.
* Atomic Data Access:: A single handler can run in the middle of
- reading or writing a single object.
+ reading or writing a single object.
@end menu
@node Handler Returns
waiting_for_input = 1;
@dots{}
waiting_for_input = 0;
- @} else @{
+ @} else @{
@dots{}
@}
@}
struct process *p;
/* @r{Keep asking for a status until we get a definitive result.} */
- do
+ do
@{
errno = 0;
pid = waitpid (WAIT_ANY, &w, WNOHANG | WUNTRACED);
@end smallexample
@node Nonreentrancy
-@subsection Signal Handling and Nonreentrant Functions
+@subsection Signal Handling and Nonreentrant Functions
@cindex restrictions on signal handler functions
Handler functions usually don't do very much. The best practice is to
machine.
@comment signal.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} sig_atomic_t
This is an integer data type. Objects of this type are always accessed
atomically.
@pindex signal.h
@comment signal.h
-@comment ANSI
+@comment ISO
@deftypefun int raise (int @var{signum})
The @code{raise} function sends the signal @var{signum} to the calling
process. It returns zero if successful and a nonzero value if it fails.
@end group
@end smallexample
-@strong{Portability note:} @code{raise} was invented by the ANSI C
+@strong{Portability note:} @code{raise} was invented by the @w{ISO C}
committee. Older systems may not support it, so using @code{kill} may
be more portable. @xref{Signaling Another Process}.
@itemize @bullet
@item
You can use the @code{sigprocmask} function to block signals while you
-modify global variables that are also modified by the handlers for these
+modify global variables that are also modified by the handlers for these
signals.
@item
@menu
* Why Block:: The purpose of blocking signals.
* Signal Sets:: How to specify which signals to
- block.
+ block.
* Process Signal Mask:: Blocking delivery of signals to your
process during normal execution.
* Testing for Delivery:: Blocking to Test for Delivery of
- a Signal.
+ a Signal.
* Blocking for Handler:: Blocking additional signals while a
handler is being run.
* Checking for Pending Signals:: Checking for Pending Signals
* Remembering a Signal:: How you can get almost the same
effect as blocking a signal, by
handling it and setting a flag
- to be tested later.
+ to be tested later.
@end menu
@node Why Block
sigaddset (&base_mask, SIGTSTP);
/* @r{Block user interrupts while doing other processing.} */
-sigprocmask (SIG_SETMASK, &base_mask, NULL);
+sigprocmask (SIG_SETMASK, &base_mask, NULL);
@dots{}
/* @r{After a while, check to see whether any signals are pending.} */
The mask remains @var{set} only as long as @code{sigsuspend} is waiting.
The function @code{sigsuspend} always restores the previous signal mask
-when it returns.
+when it returns.
The return value and error conditions are the same as for @code{pause}.
@end deftypefun
@dots{}
-/* @r{Set up the mask of signals to temporarily block.} */
-sigemptyset (&mask);
+/* @r{Set up the mask of signals to temporarily block.} */
+sigemptyset (&mask);
sigaddset (&mask, SIGUSR1);
@dots{}
You tried to disable a stack that was in fact currently in use.
@item ENOMEM
-The size of the alternate stack was too small.
+The size of the alternate stack was too small.
It must be greater than @code{MINSIGSTKSZ}.
@end table
@end deftypefun
@menu
* BSD Handler:: BSD Function to Establish a Handler.
-* Blocking in BSD:: BSD Functions for Blocking Signals.
+* Blocking in BSD:: BSD Functions for Blocking Signals.
@end menu
@node BSD Handler
@end deftypefun
@node Blocking in BSD
-@subsection BSD Functions for Blocking Signals
+@subsection BSD Functions for Blocking Signals
@comment signal.h
@comment BSD
is up to you to write a function named @code{main}---otherwise, you
won't even be able to link your program without errors.
-In ANSI C you can define @code{main} either to take no arguments, or to
+In @w{ISO C} you can define @code{main} either to take no arguments, or to
take two arguments that represent the command line arguments to the
program, like this:
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} getenv (const char *@var{name})
This function returns a string that is the value of the environment
variable @var{name}. You must not modify this string. In some non-Unix
the value that @code{main} returns is used as the argument to @code{exit}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void exit (int @var{status})
The @code{exit} function terminates the process with status
@var{status}. This function does not return.
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int EXIT_SUCCESS
This macro can be used with the @code{exit} function to indicate
successful program completion.
@end deftypevr
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int EXIT_FAILURE
This macro can be used with the @code{exit} function to indicate
unsuccessful program completion in a general sense.
using @code{atexit} or @code{on_exit}.
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun int atexit (void (*@var{function}) (void))
The @code{atexit} function registers the function @var{function} to be
called at normal program termination. The @var{function} is called with
@pindex stdlib.h
@comment stdlib.h
-@comment ANSI
+@comment ISO
@deftypefun void abort (void)
The @code{abort} function causes abnormal program termination. This
does not execute cleanup functions registered with @code{atexit} or
* Binary Streams:: Some systems distinguish between text files
and binary files.
* File Positioning:: About random-access streams.
-* Portable Positioning:: Random access on peculiar ANSI C systems.
+* Portable Positioning:: Random access on peculiar ISO C systems.
* Stream Buffering:: How to control buffering of streams.
* Other Kinds of Streams:: Streams that do not necessarily correspond
to an open file.
The @code{FILE} type is declared in the header file @file{stdio.h}.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} FILE
This is the data type used to represent stream objects. A @code{FILE}
object holds all of the internal state information about the connection
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevar {FILE *} stdin
The @dfn{standard input} stream, which is the normal source of input for the
program.
@cindex standard input stream
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevar {FILE *} stdout
The @dfn{standard output} stream, which is used for normal output from
the program.
@cindex standard output stream
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevar {FILE *} stderr
The @dfn{standard error} stream, which is used for error messages and
diagnostics issued by the program.
@file{stdio.h}.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {FILE *} fopen (const char *@var{filename}, const char *@var{opentype})
The @code{fopen} function opens a stream for I/O to the file
@var{filename}, and returns a pointer to the stream.
@end table
As you can see, @samp{+} requests a stream that can do both input and
-output. The ANSI standard says that when using such a stream, you must
+output. The ISO standard says that when using such a stream, you must
call @code{fflush} (@pxref{Stream Buffering}) or a file positioning
function such as @code{fseek} (@pxref{File Positioning}) when switching
from reading to writing or vice versa. Otherwise, internal buffers
Locks}.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int FOPEN_MAX
The value of this macro is an integer constant expression that
represents the minimum number of streams that the implementation
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {FILE *} freopen (const char *@var{filename}, const char *@var{opentype}, FILE *@var{stream})
This function is like a combination of @code{fclose} and @code{fopen}.
It first closes the stream referred to by @var{stream}, ignoring any
cannot perform any additional operations on it.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fclose (FILE *@var{stream})
This function causes @var{stream} to be closed and the connection to
the corresponding file to be broken. Any buffered output is written
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fputc (int @var{c}, FILE *@var{stream})
The @code{fputc} function converts the character @var{c} to type
@code{unsigned char}, and writes it to the stream @var{stream}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int putc (int @var{c}, FILE *@var{stream})
This is just like @code{fputc}, except that most systems implement it as
a macro, making it faster. One consequence is that it may evaluate the
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int putchar (int @var{c})
The @code{putchar} function is equivalent to @code{putc} with
@code{stdout} as the value of the @var{stream} argument.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fputs (const char *@var{s}, FILE *@var{stream})
The function @code{fputs} writes the string @var{s} to the stream
@var{stream}. The terminating null character is not written.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int puts (const char *@var{s})
The @code{puts} function writes the string @var{s} to the stream
@code{stdout} followed by a newline. The terminating null character of
variable without loss of information.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fgetc (FILE *@var{stream})
This function reads the next character as an @code{unsigned char} from
the stream @var{stream} and returns its value, converted to an
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int getc (FILE *@var{stream})
This is just like @code{fgetc}, except that it is permissible (and
typical) for it to be implemented as a macro that evaluates the
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int getchar (void)
The @code{getchar} function is equivalent to @code{getc} with @code{stdin}
as the value of the @var{stream} argument.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} fgets (char *@var{s}, int @var{count}, FILE *@var{stream})
The @code{fgets} function reads characters from the stream @var{stream}
up to and including a newline character and stores them in the string
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefn {Deprecated function} {char *} gets (char *@var{s})
The function @code{gets} reads characters from the stream @code{stdin}
up to the next newline character, and stores them in the string @var{s}.
reverses the action of @code{getc}.
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int ungetc (int @var{c}, FILE *@var{stream})
The @code{ungetc} function pushes back the character @var{c} onto the
input stream @var{stream}. So the next input from @var{stream} will
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun size_t fread (void *@var{data}, size_t @var{size}, size_t @var{count}, FILE *@var{stream})
This function reads up to @var{count} objects of size @var{size} into
the array @var{data}, from the stream @var{stream}. It returns the
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun size_t fwrite (const void *@var{data}, size_t @var{size}, size_t @var{count}, FILE *@var{stream})
This function writes up to @var{count} objects of size @var{size} from
the array @var{data}, to the stream @var{stream}. The return value is
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int printf (const char *@var{template}, @dots{})
The @code{printf} function prints the optional arguments under the
control of the template string @var{template} to the stream
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fprintf (FILE *@var{stream}, const char *@var{template}, @dots{})
This function is just like @code{printf}, except that the output is
written to the stream @var{stream} instead of @code{stdout}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int sprintf (char *@var{s}, const char *@var{template}, @dots{})
This is like @code{printf}, except that the output is stored in the character
array @var{s} instead of written to a stream. A null character is written
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int vprintf (const char *@var{template}, va_list @var{ap})
This function is similar to @code{printf} except that, instead of taking
a variable number of arguments directly, it takes an argument list
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int vfprintf (FILE *@var{stream}, const char *@var{template}, va_list @var{ap})
This is the equivalent of @code{fprintf} with the variable argument list
specified directly as for @code{vprintf}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int vsprintf (char *@var{s}, const char *@var{template}, va_list @var{ap})
This is the equivalent of @code{sprintf} with the variable argument list
specified directly as for @code{vprintf}.
@end menu
@strong{Portability Note:} The ability to extend the syntax of
-@code{printf} template strings is a GNU extension. ANSI standard C has
+@code{printf} template strings is a GNU extension. ISO standard C has
nothing similar.
@node Registering New Conversions
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int scanf (const char *@var{template}, @dots{})
The @code{scanf} function reads formatted input from the stream
@code{stdin} under the control of the template string @var{template}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fscanf (FILE *@var{stream}, const char *@var{template}, @dots{})
This function is just like @code{scanf}, except that the input is read
from the stream @var{stream} instead of @code{stdin}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int sscanf (const char *@var{s}, const char *@var{template}, @dots{})
This is like @code{scanf}, except that the characters are taken from the
null-terminated string @var{s} instead of from a stream. Reaching the
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int EOF
This macro is an integer value that is returned by a number of functions
to indicate an end-of-file condition, or some other error situation.
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun void clearerr (FILE *@var{stream})
This function clears the end-of-file and error indicators for the
stream @var{stream}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int feof (FILE *@var{stream})
The @code{feof} function returns nonzero if and only if the end-of-file
indicator for the stream @var{stream} is set.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int ferror (FILE *@var{stream})
The @code{ferror} function returns nonzero if and only if the error
indicator for the stream @var{stream} is set, indicating that an error
The GNU system and other POSIX-compatible operating systems organize all
files as uniform sequences of characters. However, some other systems
make a distinction between files containing text and files containing
-binary data, and the input and output facilities of ANSI C provide for
+binary data, and the input and output facilities of @w{ISO C} provide for
this distinction. This section tells you how to write programs portable
to such systems.
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun {long int} ftell (FILE *@var{stream})
This function returns the current file position of the stream
@var{stream}.
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fseek (FILE *@var{stream}, long int @var{offset}, int @var{whence})
The @code{fseek} function is used to change the file position of the
stream @var{stream}. The value of @var{whence} must be one of the
(@pxref{Control Operations}).
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SEEK_SET
This is an integer constant which, when used as the @var{whence}
argument to the @code{fseek} function, specifies that the offset
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SEEK_CUR
This is an integer constant which, when used as the @var{whence}
argument to the @code{fseek} function, specifies that the offset
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int SEEK_END
This is an integer constant which, when used as the @var{whence}
argument to the @code{fseek} function, specifies that the offset
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun void rewind (FILE *@var{stream})
The @code{rewind} function positions the stream @var{stream} at the
begining of the file. It is equivalent to calling @code{fseek} on the
On the GNU system, the file position is truly a character count. You
can specify any character count value as an argument to @code{fseek} and
-get reliable results for any random access file. However, some ANSI C
+get reliable results for any random access file. However, some @w{ISO C}
systems do not represent file positions in this way.
On some systems where text streams truly differ from binary streams, it
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} fpos_t
This is the type of an object that can encode information about the
file position of a stream, for use by the functions @code{fgetpos} and
@end deftp
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fgetpos (FILE *@var{stream}, fpos_t *@var{position})
This function stores the value of the file position indicator for the
stream @var{stream} in the @code{fpos_t} object pointed to by
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fsetpos (FILE *@var{stream}, const fpos_t @var{position})
This function sets the file position indicator for the stream @var{stream}
to the position @var{position}, which must have been set by a previous
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int fflush (FILE *@var{stream})
This function causes any buffered output on @var{stream} to be delivered
to the file. If @var{stream} is a null pointer, then
@pindex stdio.h
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun int setvbuf (FILE *@var{stream}, char *@var{buf}, int @var{mode}, size_t @var{size})
This function is used to specify that the stream @var{stream} should
have the buffering mode @var{mode}, which can be either @code{_IOFBF}
@end deftypefun
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int _IOFBF
The value of this macro is an integer constant expression that can be
used as the @var{mode} argument to the @code{setvbuf} function to
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int _IOLBF
The value of this macro is an integer constant expression that can be
used as the @var{mode} argument to the @code{setvbuf} function to
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int _IONBF
The value of this macro is an integer constant expression that can be
used as the @var{mode} argument to the @code{setvbuf} function to
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int BUFSIZ
The value of this macro is an integer constant expression that is good
to use for the @var{size} argument to @code{setvbuf}. This value is
@end deftypevr
@comment stdio.h
-@comment ANSI
+@comment ISO
@deftypefun void setbuf (FILE *@var{stream}, char *@var{buf})
If @var{buf} is a null pointer, the effect of this function is
equivalent to calling @code{setvbuf} with a @var{mode} argument of
@cindex string literal
@dfn{String literals} appear in C program source as strings of
-characters between double-quote characters (@samp{"}). In ANSI C,
+characters between double-quote characters (@samp{"}). In @w{ISO C},
string literals can also be formed by @dfn{string concatenation}:
@code{"a" "b"} is the same as @code{"ab"}. Modification of string
literals is not allowed by the GNU C compiler, because literals
@pindex string.h
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun size_t strlen (const char *@var{s})
The @code{strlen} function returns the length of the null-terminated
string @var{s}. (In other words, it returns the offset of the terminating
Functions}).
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} memcpy (void *@var{to}, const void *@var{from}, size_t @var{size})
The @code{memcpy} function copies @var{size} bytes from the object
beginning at @var{from} into the object beginning at @var{to}. The
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} memmove (void *@var{to}, const void *@var{from}, size_t @var{size})
@code{memmove} copies the @var{size} bytes at @var{from} into the
@var{size} bytes at @var{to}, even if those two blocks of space
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} memset (void *@var{block}, int @var{c}, size_t @var{size})
This function copies the value of @var{c} (converted to an
@code{unsigned char}) into each of the first @var{size} bytes of the
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strcpy (char *@var{to}, const char *@var{from})
This copies characters from the string @var{from} (up to and including
the terminating null character) into the string @var{to}. Like
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strncpy (char *@var{to}, const char *@var{from}, size_t @var{size})
This function is similar to @code{strcpy} but always copies exactly
@var{size} characters into @var{to}.
If the length of @var{from} is less than @var{size}, then @code{strncpy}
copies all of @var{from}, followed by enough null characters to add up
to @var{size} characters in all. This behavior is rarely useful, but it
-is specified by the ANSI C standard.
+is specified by the @w{ISO C} standard.
The behavior of @code{strncpy} is undefined if the strings overlap.
@include stpcpy.c.texi
@end smallexample
-This function is not part of the ANSI or POSIX standards, and is not
+This function is not part of the ISO or POSIX standards, and is not
customary on Unix systems, but we did not invent it either. Perhaps it
comes from MS-DOG.
@code{strncpy} is used. @code{stpncpy} returns a pointer to the
@emph{first} written null character.
-This function is not part of ANSI or POSIX but was found useful while
+This function is not part of ISO or POSIX but was found useful while
developing GNU C Library itself.
Its behaviour is undefined if the strings overlap.
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strcat (char *@var{to}, const char *@var{from})
The @code{strcat} function is similar to @code{strcpy}, except that the
characters from @var{from} are concatenated or appended to the end of
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strncat (char *@var{to}, const char *@var{from}, size_t @var{size})
This function is like @code{strcat} except that not more than @var{size}
characters from @var{from} are appended to the end of @var{to}. A
@pindex string.h
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun int memcmp (const void *@var{a1}, const void *@var{a2}, size_t @var{size})
The function @code{memcmp} compares the @var{size} bytes of memory
beginning at @var{a1} against the @var{size} bytes of memory beginning
@code{struct foo} objects instead of comparing them with @code{memcmp}.
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun int strcmp (const char *@var{s1}, const char *@var{s2})
The @code{strcmp} function compares the string @var{s1} against
@var{s2}, returning a value that has the same sign as the difference
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun int strncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{size})
This function is the similar to @code{strcmp}, except that no more than
@var{size} characters are compared. In other words, if the two strings are
compare the transformed strings with @code{strcmp}.
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun int strcoll (const char *@var{s1}, const char *@var{s2})
The @code{strcoll} function is similar to @code{strcmp} but uses the
collating sequence of the current locale for collation (the
@cindex converting string to collation order
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun size_t strxfrm (char *@var{to}, const char *@var{from}, size_t @var{size})
The function @code{strxfrm} transforms @var{string} using the collation
transformation determined by the locale currently selected for
@end smallexample
@strong{Compatibility Note:} The string collation functions are a new
-feature of ANSI C. Older C dialects have no equivalent feature.
+feature of @w{ISO C}. Older C dialects have no equivalent feature.
@node Search Functions, Finding Tokens in a String, Collation Functions, String and Array Utilities
@section Search Functions
@cindex string search functions
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {void *} memchr (const void *@var{block}, int @var{c}, size_t @var{size})
This function finds the first occurrence of the byte @var{c} (converted
to an @code{unsigned char}) in the initial @var{size} bytes of the
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strchr (const char *@var{string}, int @var{c})
The @code{strchr} function finds the first occurrence of the character
@var{c} (converted to a @code{char}) in the null-terminated string
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strrchr (const char *@var{string}, int @var{c})
The function @code{strrchr} is like @code{strchr}, except that it searches
backwards from the end of the string @var{string} (instead of forwards
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strstr (const char *@var{haystack}, const char *@var{needle})
This is like @code{strchr}, except that it searches @var{haystack} for a
substring @var{needle} rather than just a single character. It
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun size_t strspn (const char *@var{string}, const char *@var{skipset})
The @code{strspn} (``string span'') function returns the length of the
initial substring of @var{string} that consists entirely of characters that
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun size_t strcspn (const char *@var{string}, const char *@var{stopset})
The @code{strcspn} (``string complement span'') function returns the length
of the initial substring of @var{string} that consists entirely of characters
@end deftypefun
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strpbrk (const char *@var{string}, const char *@var{stopset})
The @code{strpbrk} (``string pointer break'') function is related to
@code{strcspn}, except that it returns a pointer to the first character
@pindex string.h
@comment string.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} strtok (char *@var{newstring}, const char *@var{delimiters})
A string can be split into tokens by making a series of calls to the
function @code{strtok}.
what the underlying representation is.
@comment time.h
-@comment ANSI
+@comment ISO
@deftypevr Macro int CLOCKS_PER_SEC
The value of this macro is the number of clock ticks per second measured
by the @code{clock} function.
@end deftypevr
@comment time.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} clock_t
This is the type of the value returned by the @code{clock} function.
Values of type @code{clock_t} are in units of clock ticks.
@end deftp
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun clock_t clock (void)
This function returns the elapsed processor time. The base time is
arbitrary but doesn't change within a single process. If the processor
@end deftypefun
@strong{Portability Note:} The @code{clock} function described in
-@ref{Basic CPU Time}, is specified by the ANSI C standard. The
+@ref{Basic CPU Time}, is specified by the @w{ISO C} standard. The
@code{times} function is a feature of POSIX.1. In the GNU system, the
value returned by the @code{clock} function is equivalent to the sum of
the @code{tms_utime} and @code{tms_stime} fields returned by
@cindex epoch
@comment time.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} time_t
This is the data type used to represent calendar time.
When interpreted as an absolute time
@end deftp
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun double difftime (time_t @var{time1}, time_t @var{time0})
The @code{difftime} function returns the number of seconds elapsed
between time @var{time1} and time @var{time0}, as a value of type
@end deftypefun
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun time_t time (time_t *@var{result})
The @code{time} function returns the current time as a value of type
@code{time_t}. If the argument @var{result} is not a null pointer, the
The symbols in this section are declared in the header file @file{time.h}.
@comment time.h
-@comment ANSI
+@comment ISO
@deftp {Data Type} {struct tm}
This is the data type used to represent a broken-down time. The structure
contains at least the following members, which can appear in any order:
You can also think of this as the number of seconds east of UTC. For
example, for U.S. Eastern Standard Time, the value is @code{-5*60*60}.
The @code{tm_gmtoff} field is derived from BSD and is a GNU library
-extension; it is not visible in a strict ANSI C environment.
+extension; it is not visible in a strict @w{ISO C} environment.
@item const char *tm_zone
This field is the name for the time zone that was used to compute this
broken-down time value. Like @code{tm_gmtoff}, this field is a BSD and
-GNU extension, and is not visible in a strict ANSI C environment.
+GNU extension, and is not visible in a strict @w{ISO C} environment.
@end table
@end deftp
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun {struct tm *} localtime (const time_t *@var{time})
The @code{localtime} function converts the calendar time pointed to by
@var{time} to broken-down time representation, expressed relative to the
@end deftypefun
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun {struct tm *} gmtime (const time_t *@var{time})
This function is similar to @code{localtime}, except that the broken-down
time is expressed as Coordinated Universal Time (UTC)---that is, as
@end deftypefun
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun time_t mktime (struct tm *@var{brokentime})
The @code{mktime} function is used to convert a broken-down time structure
to a calendar time representation. It also ``normalizes'' the contents of
@pindex time.h
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} asctime (const struct tm *@var{brokentime})
The @code{asctime} function converts the broken-down time value that
@var{brokentime} points to into a string in a standard format:
@end deftypefun
@comment time.h
-@comment ANSI
+@comment ISO
@deftypefun {char *} ctime (const time_t *@var{time})
The @code{ctime} function is similar to @code{asctime}, except that the
time value is specified as a @code{time_t} calendar time value rather
@end deftypefun
@comment time.h
-@comment ANSI
+@comment ISO
@comment POSIX.2
@deftypefun size_t strftime (char *@var{s}, size_t @var{size}, const char *@var{template}, const struct tm *@var{brokentime})
This function is similar to the @code{sprintf} function (@pxref{Formatted