fbbd9655e5
Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96
170 lines
4.2 KiB
Groff
170 lines
4.2 KiB
Groff
.\" 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.
|
|
.\" 3. 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.
|