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Diffstat (limited to 'lib/libc/stdio/getc.3')
-rw-r--r-- | lib/libc/stdio/getc.3 | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/lib/libc/stdio/getc.3 b/lib/libc/stdio/getc.3 new file mode 100644 index 0000000..d0f3c15 --- /dev/null +++ b/lib/libc/stdio/getc.3 @@ -0,0 +1,169 @@ +.\" Copyright (c) 1990, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" Chris Torek and the American National Standards Committee X3, +.\" on Information Processing Systems. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)getc.3 8.1 (Berkeley) 6/4/93 +.\" $FreeBSD$ +.\" +.Dd January 10, 2003 +.Dt GETC 3 +.Os +.Sh NAME +.Nm fgetc , +.Nm getc , +.Nm getc_unlocked , +.Nm getchar , +.Nm getchar_unlocked , +.Nm getw +.Nd get next character or word from input stream +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In stdio.h +.Ft int +.Fn fgetc "FILE *stream" +.Ft int +.Fn getc "FILE *stream" +.Ft int +.Fn getc_unlocked "FILE *stream" +.Ft int +.Fn getchar void +.Ft int +.Fn getchar_unlocked void +.Ft int +.Fn getw "FILE *stream" +.Sh DESCRIPTION +The +.Fn fgetc +function +obtains the next input character (if present) from the stream pointed at by +.Fa stream , +or the next character pushed back on the stream via +.Xr ungetc 3 . +.Pp +The +.Fn getc +function +acts essentially identically to +.Fn fgetc , +but is a macro that expands in-line. +.Pp +The +.Fn getchar +function +is equivalent to +.Fn getc stdin . +.Pp +The +.Fn getw +function +obtains the next +.Vt int +(if present) +from the stream pointed at by +.Fa stream . +.Pp +The +.Fn getc_unlocked +and +.Fn getchar_unlocked +functions are equivalent to +.Fn getc +and +.Fn getchar +respectively, +except that the caller is responsible for locking the stream +with +.Xr flockfile 3 +before calling them. +These functions may be used to avoid the overhead of locking the stream +for each character, and to avoid input being dispersed among multiple +threads reading from the same stream. +.Sh RETURN VALUES +If successful, these routines return the next requested object +from the +.Fa stream . +Character values are returned as an +.Vt "unsigned char" +converted to an +.Vt int . +If the stream is at end-of-file or a read error occurs, +the routines return +.Dv EOF . +The routines +.Xr feof 3 +and +.Xr ferror 3 +must be used to distinguish between end-of-file and error. +If an error occurs, the global variable +.Va errno +is set to indicate the error. +The end-of-file condition is remembered, even on a terminal, and all +subsequent attempts to read will return +.Dv EOF +until the condition is cleared with +.Xr clearerr 3 . +.Sh SEE ALSO +.Xr ferror 3 , +.Xr flockfile 3 , +.Xr fopen 3 , +.Xr fread 3 , +.Xr getwc 3 , +.Xr putc 3 , +.Xr ungetc 3 +.Sh STANDARDS +The +.Fn fgetc , +.Fn getc , +and +.Fn getchar +functions +conform to +.St -isoC . +The +.Fn getc_unlocked +and +.Fn getchar_unlocked +functions conform to +.St -p1003.1-2001 . +.Sh BUGS +Since +.Dv EOF +is a valid integer value, +.Xr feof 3 +and +.Xr ferror 3 +must be used to check for failure after calling +.Fn getw . +The size and byte order of an +.Vt int +varies from one machine to another, and +.Fn getw +is not recommended for portable applications. |