you will know what they are when they are mentioned in other parts of
the manual.
-For information about what standards specify what features,
-@pxref{Summary of Library Facilities}.
+@xref{Summary of Library Facilities} for information about what
+standards specify what features.
@menu
* ANSI C:: The American National Standard for the
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''}.
The header files and library facilities that make up the GNU library are
a superset of those specified by the ANSI C standard.@refill
(Recall that in C, a @dfn{declaration} merely provides information that
a function or variable exists and gives its type. For a function
declaration, information about the types of its arguments might be
-provided as well. The purpose of declarations are to allow the compiler
+provided as well. The purpose of declarations is to allow the compiler
to correctly process references to the declared variables and functions.
A @dfn{definition}, on the other hand, actually allocates storage for a
variable or says what a function does.)
Header files are included into a program source file by the
@samp{#include} preprocessor directive. The C language supports two
-forms of this directive:
+forms of this directive; the first,
@example
-#include "@var{file.h}"
+#include "@var{header}"
@end example
@noindent
-is typically used to include a header file @file{file.h} that you write
-yourself that contains definitions and declarations about the interfaces
-between the different parts of your particular application, while
+is typically used to include a header file @var{header} that you write
+yourself; this would contain definitions and declarations describing the
+interfaces between the different parts of your particular application.
+By contrast,
@example
#include <file.h>
@noindent
is typically used to include a header file @file{file.h} that contains
-definitions and declarations for a standard library, that is normally
-installed in a standard place by your system administrator. You should
-use this second form for the C library header files.
+definitions and declarations for a standard library. This file would
+normally be installed in a standard place by your system administrator.
+You should use this second form for the C library header files.
For more information about the use of header files and @samp{#include}
directives, @pxref{Header Files,,, cpp.texinfo, The GNU C Preprocessor
necessary to recognize the a macro call.
You might occasionally want to avoid using the a macro definition of a
-function --- perhaps to make your program easier to debug. There are
+function---perhaps to make your program easier to debug. There are
two ways you can do this:
@itemize @bullet
@noindent
the reference to @code{abs} might refer to either a macro or a function.
-On the other hand, in each of the following examples, the reference is
+On the other hand, in each of the following examples the reference is
to a function and not a macro.
@example
built-in parts of the language.
@end itemize
-In addition to the names documented in this manual, all external
-identifiers (global functions and variables) that begin with an
-underscore (@samp{_}) and all other identifiers that begin with either
-two underscores or an underscore followed by a capital letter are
-reserved names. This is so that functions, variables, and macros
-internal to the workings of the C library or the compiler can be defined
-without intruding on the name space of user programs, and without the
-possibility of a user program redefining names used internally in the
-implementation of the library.
+In addition to the names documented in this manual, reserved names
+include all external identifiers (global functions and variables) that
+begin with an underscore (@samp{_}) and all identifiers regardless of
+use that begin with either two underscores or an underscore followed by
+a capital letter are reserved names. This is so that the library and
+header files can define functions, variables, and macros for internal
+purposes without risk of conflict with names in user programs.
Some additional classes of identifier names are reserved for future
extensions to the C language. While using these names for your own
-purposes right now might not cause a problem, this raises the
+purposes right now might not cause a problem, they do raise the
possibility of conflict with future versions of the C standard, so you
should avoid these names.
@item
Names of all existing mathematics functions (@pxref{Mathematics})
suffixed with @samp{f} or @samp{l} are reserved for corresponding
-functions that operate on @code{float} or @code{long double} arguments
-(respectively).
+functions that operate on @code{float} or @code{long double} arguments,
+respectively.
@item
Names that begin with @samp{SIG} followed by an uppercase letter are
Names that end with @samp{_t} are reserved for additional type names.
@end itemize
-In addition to this, some individual header files reserve names beyond
+In addition, some individual header files reserve names beyond
those that they actually define. You only need to worry about these
restrictions if your program includes that particular header file.
such as file names.
@item
-@ref{Input/Output on Streams}, describes i/o operations involving
+@ref{Input/Output on Streams}, describes I/O operations involving
streams (or @code{FILE *} objects). These are the normal C library
functions from @file{stdio.h}.
@item
-@ref{Low-Level Input/Output}, contains information about i/o operations
+@ref{Low-Level Input/Output}, contains information about I/O operations
on file descriptors. File descriptors are a lower-level mechanism
specific to the Unix family of operating systems.
@code{longjmp} functions.
@item
-@ref{Signal Handling}, tells you all about signals --- what they are,
+@ref{Signal Handling}, tells you all about signals---what they are,
how to establish a handler that is called when a particular kind of
signal is delivered, and how to prevent signals from arriving during
critical sections of your program.
projects / kopensolaris-gnu / glibc.git / commitdiff