1 /* Copyright (C) 1993, 1995, 1997 Free Software Foundation, Inc.
2 This file is part of the GNU IO Library.
3 Written by Per Bothner <bothner@cygnus.com>.
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License as
7 published by the Free Software Foundation; either version 2, or (at
8 your option) any later version.
10 This library is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this library; see the file COPYING. If not, write to
17 the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
20 As a special exception, if you link this library with files
21 compiled with a GNU compiler to produce an executable, this does
22 not cause the resulting executable to be covered by the GNU General
23 Public License. This exception does not however invalidate any
24 other reasons why the executable file might be covered by the GNU
25 General Public License. */
27 /* This is a compatibility file. If we don't build the libc with
28 versioning don't compile this file. */
33 # define _POSIX_SOURCE
37 #include <sys/types.h>
45 # define __set_errno(Val) errno = (Val)
50 # define open(Name, Flags, Prot) __open (Name, Flags, Prot)
51 # define close(FD) __close (FD)
52 # define fstat(FD, Statbuf) __fstat (FD, Statbuf)
53 # define lseek(FD, Offset, Whence) __lseek (FD, Offset, Whence)
54 # define read(FD, Buf, NBytes) __read (FD, Buf, NBytes)
55 # define write(FD, Buf, NBytes) __write (FD, Buf, NBytes)
58 /* An fstream can be in at most one of put mode, get mode, or putback mode.
59 Putback mode is a variant of get mode.
61 In a filebuf, there is only one current position, instead of two
62 separate get and put pointers. In get mode, the current position
63 is that of gptr(); in put mode that of pptr().
65 The position in the buffer that corresponds to the position
66 in external file system is normally _IO_read_end, except in putback
67 mode, when it is _IO_save_end.
68 If the field _fb._offset is >= 0, it gives the offset in
69 the file as a whole corresponding to eGptr(). (?)
72 If a filebuf is in put mode, then all of _IO_read_ptr, _IO_read_end,
73 and _IO_read_base are equal to each other. These are usually equal
74 to _IO_buf_base, though not necessarily if we have switched from
75 get mode to put mode. (The reason is to maintain the invariant
76 that _IO_read_end corresponds to the external file position.)
77 _IO_write_base is non-NULL and usually equal to _IO_base_base.
78 We also have _IO_write_end == _IO_buf_end, but only in fully buffered mode.
79 The un-flushed character are those between _IO_write_base and _IO_write_ptr.
82 If a filebuf is in get or putback mode, eback() != egptr().
83 In get mode, the unread characters are between gptr() and egptr().
84 The OS file position corresponds to that of egptr().
87 Putback mode is used to remember "excess" characters that have
88 been sputbackc'd in a separate putback buffer.
89 In putback mode, the get buffer points to the special putback buffer.
90 The unread characters are the characters between gptr() and egptr()
91 in the putback buffer, as well as the area between save_gptr()
92 and save_egptr(), which point into the original reserve buffer.
93 (The pointers save_gptr() and save_egptr() are the values
94 of gptr() and egptr() at the time putback mode was entered.)
95 The OS position corresponds to that of save_egptr().
98 During line buffered output, _IO_write_base==base() && epptr()==base().
99 However, ptr() may be anywhere between base() and ebuf().
100 This forces a call to filebuf::overflow(int C) on every put.
101 If there is more space in the buffer, and C is not a '\n',
102 then C is inserted, and pptr() incremented.
105 If a filebuf is unbuffered(), the _shortbuf[1] is used as the buffer.
108 #define CLOSED_FILEBUF_FLAGS \
109 (_IO_IS_FILEBUF+_IO_NO_READS+_IO_NO_WRITES+_IO_TIED_PUT_GET)
113 _IO_old_file_init (fp)
116 /* POSIX.1 allows another file handle to be used to change the position
117 of our file descriptor. Hence we actually don't know the actual
118 position before we do the first fseek (and until a following fflush). */
119 fp->_old_offset = _IO_pos_BAD;
120 fp->_IO_file_flags |= CLOSED_FILEBUF_FLAGS;
127 _IO_old_file_close_it (fp)
130 int write_status, close_status;
131 if (!_IO_file_is_open (fp))
134 write_status = _IO_do_flush (fp);
136 _IO_unsave_markers(fp);
138 close_status = _IO_SYSCLOSE (fp);
141 _IO_setb (fp, NULL, NULL, 0);
142 _IO_setg (fp, NULL, NULL, NULL);
143 _IO_setp (fp, NULL, NULL);
146 fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS;
148 fp->_old_offset = _IO_pos_BAD;
150 return close_status ? close_status : write_status;
154 _IO_old_file_finish (fp, dummy)
158 if (_IO_file_is_open (fp))
161 if (!(fp->_flags & _IO_DELETE_DONT_CLOSE))
164 _IO_default_finish (fp, 0);
168 _IO_old_file_fopen (fp, filename, mode)
170 const char *filename;
173 int oflags = 0, omode;
174 int read_write, fdesc;
176 if (_IO_file_is_open (fp))
182 read_write = _IO_NO_WRITES;
186 oflags = O_CREAT|O_TRUNC;
187 read_write = _IO_NO_READS;
191 oflags = O_CREAT|O_APPEND;
192 read_write = _IO_NO_READS|_IO_IS_APPENDING;
195 __set_errno (EINVAL);
198 if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
201 read_write &= _IO_IS_APPENDING;
203 fdesc = open (filename, omode|oflags, oprot);
207 _IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
208 if (read_write & _IO_IS_APPENDING)
209 if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT)
210 == _IO_pos_BAD && errno != ESPIPE)
217 _IO_old_file_attach (fp, fd)
221 if (_IO_file_is_open (fp))
224 fp->_flags &= ~(_IO_NO_READS+_IO_NO_WRITES);
225 fp->_flags |= _IO_DELETE_DONT_CLOSE;
226 /* Get the current position of the file. */
227 /* We have to do that since that may be junk. */
228 fp->_old_offset = _IO_pos_BAD;
229 if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_cur, _IOS_INPUT|_IOS_OUTPUT)
230 == _IO_pos_BAD && errno != ESPIPE)
236 _IO_old_file_setbuf (fp, p, len)
241 if (_IO_default_setbuf (fp, p, len) == NULL)
244 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
246 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
251 /* Write TO_DO bytes from DATA to FP.
252 Then mark FP as having empty buffers. */
255 _IO_old_do_write (fp, data, to_do)
263 if (fp->_flags & _IO_IS_APPENDING)
264 /* On a system without a proper O_APPEND implementation,
265 you would need to sys_seek(0, SEEK_END) here, but is
266 is not needed nor desirable for Unix- or Posix-like systems.
267 Instead, just indicate that offset (before and after) is
269 fp->_old_offset = _IO_pos_BAD;
270 else if (fp->_IO_read_end != fp->_IO_write_base)
273 = _IO_SYSSEEK (fp, fp->_IO_write_base - fp->_IO_read_end, 1);
274 if (new_pos == _IO_pos_BAD)
276 fp->_old_offset = new_pos;
278 count = _IO_SYSWRITE (fp, data, to_do);
280 fp->_cur_column = _IO_adjust_column (fp->_cur_column - 1, data, to_do) + 1;
281 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
282 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_buf_base;
283 fp->_IO_write_end = ((fp->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
284 ? fp->_IO_buf_base : fp->_IO_buf_end);
285 return count != to_do ? EOF : 0;
289 _IO_old_file_underflow (fp)
294 /* SysV does not make this test; take it out for compatibility */
295 if (fp->_flags & _IO_EOF_SEEN)
299 if (fp->_flags & _IO_NO_READS)
304 if (fp->_IO_read_ptr < fp->_IO_read_end)
305 return *(unsigned char *) fp->_IO_read_ptr;
307 if (fp->_IO_buf_base == NULL)
310 /* Flush all line buffered files before reading. */
311 /* FIXME This can/should be moved to genops ?? */
312 if (fp->_flags & (_IO_LINE_BUF|_IO_UNBUFFERED))
313 _IO_flush_all_linebuffered ();
315 _IO_switch_to_get_mode (fp);
317 /* This is very tricky. We have to adjust those
318 pointers before we call _IO_SYSREAD () since
319 we may longjump () out while waiting for
320 input. Those pointers may be screwed up. H.J. */
321 fp->_IO_read_base = fp->_IO_read_ptr = fp->_IO_buf_base;
322 fp->_IO_read_end = fp->_IO_buf_base;
323 fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end
326 count = _IO_SYSREAD (fp, fp->_IO_buf_base,
327 fp->_IO_buf_end - fp->_IO_buf_base);
331 fp->_flags |= _IO_EOF_SEEN;
333 fp->_flags |= _IO_ERR_SEEN, count = 0;
335 fp->_IO_read_end += count;
338 if (fp->_old_offset != _IO_pos_BAD)
339 _IO_pos_adjust (fp->_old_offset, count);
340 return *(unsigned char *) fp->_IO_read_ptr;
344 _IO_old_file_overflow (f, ch)
348 if (f->_flags & _IO_NO_WRITES) /* SET ERROR */
350 f->_flags |= _IO_ERR_SEEN;
354 /* If currently reading or no buffer allocated. */
355 if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0)
357 /* Allocate a buffer if needed. */
358 if (f->_IO_write_base == 0)
361 _IO_setg (f, f->_IO_buf_base, f->_IO_buf_base, f->_IO_buf_base);
363 /* Otherwise must be currently reading.
364 If _IO_read_ptr (and hence also _IO_read_end) is at the buffer end,
365 logically slide the buffer forwards one block (by setting the
366 read pointers to all point at the beginning of the block). This
367 makes room for subsequent output.
368 Otherwise, set the read pointers to _IO_read_end (leaving that
369 alone, so it can continue to correspond to the external position). */
370 if (f->_IO_read_ptr == f->_IO_buf_end)
371 f->_IO_read_end = f->_IO_read_ptr = f->_IO_buf_base;
372 f->_IO_write_ptr = f->_IO_read_ptr;
373 f->_IO_write_base = f->_IO_write_ptr;
374 f->_IO_write_end = f->_IO_buf_end;
375 f->_IO_read_base = f->_IO_read_ptr = f->_IO_read_end;
377 if (f->_flags & (_IO_LINE_BUF+_IO_UNBUFFERED))
378 f->_IO_write_end = f->_IO_write_ptr;
379 f->_flags |= _IO_CURRENTLY_PUTTING;
382 return _IO_do_flush (f);
383 if (f->_IO_write_ptr == f->_IO_buf_end ) /* Buffer is really full */
384 if (_IO_do_flush (f) == EOF)
386 *f->_IO_write_ptr++ = ch;
387 if ((f->_flags & _IO_UNBUFFERED)
388 || ((f->_flags & _IO_LINE_BUF) && ch == '\n'))
389 if (_IO_do_flush (f) == EOF)
391 return (unsigned char) ch;
395 _IO_old_file_sync (fp)
401 _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
403 /* char* ptr = cur_ptr(); */
404 if (fp->_IO_write_ptr > fp->_IO_write_base)
405 if (_IO_do_flush(fp)) return EOF;
406 delta = fp->_IO_read_ptr - fp->_IO_read_end;
410 if (_IO_in_backup (fp))
411 delta -= eGptr () - Gbase ();
413 _IO_off_t new_pos = _IO_SYSSEEK (fp, delta, 1);
414 if (new_pos != (_IO_off_t) EOF)
415 fp->_IO_read_end = fp->_IO_read_ptr;
417 else if (errno == ESPIPE)
418 ; /* Ignore error from unseekable devices. */
424 fp->_old_offset = _IO_pos_BAD;
425 /* FIXME: Cleanup - can this be shared? */
426 /* setg(base(), ptr, ptr); */
427 _IO_cleanup_region_end (1);
432 _IO_old_file_seekoff (fp, offset, dir, mode)
439 _IO_off64_t delta, new_offset;
441 /* POSIX.1 8.2.3.7 says that after a call the fflush() the file
442 offset of the underlying file must be exact. */
443 int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
444 && fp->_IO_write_base == fp->_IO_write_ptr);
447 dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */
449 /* Flush unwritten characters.
450 (This may do an unneeded write if we seek within the buffer.
451 But to be able to switch to reading, we would need to set
452 egptr to ptr. That can't be done in the current design,
453 which assumes file_ptr() is eGptr. Anyway, since we probably
454 end up flushing when we close(), it doesn't make much difference.)
455 FIXME: simulate mem-papped files. */
457 if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp))
458 if (_IO_switch_to_get_mode (fp))
461 if (fp->_IO_buf_base == NULL)
464 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
465 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
471 /* Adjust for read-ahead (bytes is buffer). */
472 offset -= fp->_IO_read_end - fp->_IO_read_ptr;
473 if (fp->_old_offset == _IO_pos_BAD)
475 /* Make offset absolute, assuming current pointer is file_ptr(). */
476 offset += _IO_pos_as_off (fp->_old_offset);
485 if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
487 offset += st.st_size;
494 /* At this point, dir==_IO_seek_set. */
496 /* If destination is within current buffer, optimize: */
497 if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
498 && !_IO_in_backup (fp))
500 /* Offset relative to start of main get area. */
501 _IO_pos_t rel_offset = (offset - fp->_old_offset
502 + (fp->_IO_read_end - fp->_IO_read_base));
506 if (_IO_in_backup (fp))
507 _IO_switch_to_main_get_area (fp);
509 if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base)
511 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset,
513 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
517 /* If we have streammarkers, seek forward by reading ahead. */
518 if (_IO_have_markers (fp))
520 int to_skip = rel_offset
521 - (fp->_IO_read_ptr - fp->_IO_read_base);
522 if (ignore (to_skip) != to_skip)
529 if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ())
531 if (!_IO_in_backup (fp))
532 _IO_switch_to_backup_area (fp);
533 gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr);
540 _IO_unsave_markers (fp);
543 if (fp->_flags & _IO_NO_READS)
546 /* Try to seek to a block boundary, to improve kernel page management. */
547 new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
548 delta = offset - new_offset;
549 if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
554 result = _IO_SYSSEEK (fp, new_offset, 0);
561 count = _IO_SYSREAD (fp, fp->_IO_buf_base,
563 ? delta : fp->_IO_buf_end - fp->_IO_buf_base));
566 /* We weren't allowed to read, but try to seek the remainder. */
567 offset = count == EOF ? delta : delta-count;
572 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
573 fp->_IO_buf_base + count);
574 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
575 fp->_old_offset = result + count;
576 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
580 _IO_unsave_markers (fp);
581 result = _IO_SYSSEEK (fp, offset, dir);
583 _IO_mask_flags (fp, 0, _IO_EOF_SEEN);
584 fp->_old_offset = result;
585 _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
586 _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
591 _IO_old_file_write (f, data, n)
596 _IO_ssize_t to_do = n;
599 _IO_ssize_t count = write (f->_fileno, data, to_do);
602 f->_flags |= _IO_ERR_SEEN;
606 data = (void *) ((char *) data + count);
609 if (f->_old_offset >= 0)
615 _IO_old_file_xsputn (f, data, n)
620 register const char *s = (char *) data;
621 _IO_size_t to_do = n;
627 /* This is an optimized implementation.
628 If the amount to be written straddles a block boundary
629 (or the filebuf is unbuffered), use sys_write directly. */
631 /* First figure out how much space is available in the buffer. */
632 count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
633 if ((f->_flags & _IO_LINE_BUF) && (f->_flags & _IO_CURRENTLY_PUTTING))
635 count = f->_IO_buf_end - f->_IO_write_ptr;
638 register const char *p;
639 for (p = s + n; p > s; )
650 /* Then fill the buffer. */
657 memcpy (f->_IO_write_ptr, s, count);
662 register char *p = f->_IO_write_ptr;
663 register int i = (int) count;
667 f->_IO_write_ptr += count;
670 if (to_do + must_flush > 0)
672 _IO_size_t block_size, dont_write;
673 /* Next flush the (full) buffer. */
674 if (__overflow (f, EOF) == EOF)
677 /* Try to maintain alignment: write a whole number of blocks.
678 dont_write is what gets left over. */
679 block_size = f->_IO_buf_end - f->_IO_buf_base;
680 dont_write = block_size >= 128 ? to_do % block_size : 0;
682 count = to_do - dont_write;
683 if (_IO_do_write (f, s, count) == EOF)
687 /* Now write out the remainder. Normally, this will fit in the
688 buffer, but it's somewhat messier for line-buffered files,
689 so we let _IO_default_xsputn handle the general case. */
691 to_do -= _IO_default_xsputn (f, s+count, dont_write);
697 struct _IO_jump_t _IO_old_file_jumps =
700 JUMP_INIT(finish, _IO_old_file_finish),
701 JUMP_INIT(overflow, _IO_old_file_overflow),
702 JUMP_INIT(underflow, _IO_old_file_underflow),
703 JUMP_INIT(uflow, _IO_default_uflow),
704 JUMP_INIT(pbackfail, _IO_default_pbackfail),
705 JUMP_INIT(xsputn, _IO_old_file_xsputn),
706 JUMP_INIT(xsgetn, _IO_default_xsgetn),
707 JUMP_INIT(seekoff, _IO_old_file_seekoff),
708 JUMP_INIT(seekpos, _IO_default_seekpos),
709 JUMP_INIT(setbuf, _IO_old_file_setbuf),
710 JUMP_INIT(sync, _IO_file_sync),
711 JUMP_INIT(doallocate, _IO_file_doallocate),
712 JUMP_INIT(read, _IO_file_read),
713 JUMP_INIT(write, _IO_file_write),
714 JUMP_INIT(seek, _IO_file_seek),
715 JUMP_INIT(close, _IO_file_close),
716 JUMP_INIT(stat, _IO_file_stat)
720 #endif /* DO_VERSIONING */