12fe218f0b
fflush_unlocked is currently desired in ports by sysutils/metalog, and redefined as the locked fflush. fputc_unlocked, fputs_unlocked, fread_unlocked, and fwrite_unlocked are currently desired in ports by devel/elfutils, and redefined as the locked fputs, fread, and fwrite respectively. Reviewed by: kib MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D23336
171 lines
4.1 KiB
Groff
171 lines
4.1 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.
|
|
.\"
|
|
.\" @(#)putc.3 8.1 (Berkeley) 6/4/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 23, 2020
|
|
.Dt PUTC 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm fputc ,
|
|
.Nm fputc_unlocked ,
|
|
.Nm putc ,
|
|
.Nm putc_unlocked ,
|
|
.Nm putchar ,
|
|
.Nm putchar_unlocked ,
|
|
.Nm putw
|
|
.Nd output a character or word to a stream
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In stdio.h
|
|
.Ft int
|
|
.Fn fputc "int c" "FILE *stream"
|
|
.Ft int
|
|
.Fn fputc_unlocked "int c" "FILE *stream"
|
|
.Ft int
|
|
.Fn putc "int c" "FILE *stream"
|
|
.Ft int
|
|
.Fn putc_unlocked "int c" "FILE *stream"
|
|
.Ft int
|
|
.Fn putchar "int c"
|
|
.Ft int
|
|
.Fn putchar_unlocked "int c"
|
|
.Ft int
|
|
.Fn putw "int w" "FILE *stream"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn fputc
|
|
function
|
|
writes the character
|
|
.Fa c
|
|
(converted to an ``unsigned char'')
|
|
to the output stream pointed to by
|
|
.Fa stream .
|
|
.Pp
|
|
The
|
|
.Fn putc
|
|
macro acts essentially identically to
|
|
.Fn fputc ,
|
|
but is a macro that expands in-line.
|
|
It may evaluate
|
|
.Fa stream
|
|
more than once, so arguments given to
|
|
.Fn putc
|
|
should not be expressions with potential side effects.
|
|
.Pp
|
|
The
|
|
.Fn putchar
|
|
function
|
|
is identical to
|
|
.Fn putc
|
|
with an output stream of
|
|
.Dv stdout .
|
|
.Pp
|
|
The
|
|
.Fn putw
|
|
function
|
|
writes the specified
|
|
.Vt int
|
|
to the named output
|
|
.Fa stream .
|
|
.Pp
|
|
The
|
|
.Fn fputc_unlocked ,
|
|
.Fn putc_unlocked ,
|
|
and
|
|
.Fn putchar_unlocked
|
|
functions are equivalent to
|
|
.Fn fputc ,
|
|
.Fn putc ,
|
|
and
|
|
.Fn putchar
|
|
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 output being interspersed from multiple
|
|
threads writing to the same stream.
|
|
.Sh RETURN VALUES
|
|
The functions,
|
|
.Fn fputc ,
|
|
.Fn putc ,
|
|
.Fn putchar ,
|
|
.Fn putc_unlocked
|
|
and
|
|
.Fn putchar_unlocked
|
|
return the character written.
|
|
If an error occurs, the value
|
|
.Dv EOF
|
|
is returned.
|
|
The
|
|
.Fn putw
|
|
function
|
|
returns 0 on success;
|
|
.Dv EOF
|
|
is returned if
|
|
a write error occurs,
|
|
or if an attempt is made to write a read-only stream.
|
|
.Sh SEE ALSO
|
|
.Xr ferror 3 ,
|
|
.Xr flockfile 3 ,
|
|
.Xr fopen 3 ,
|
|
.Xr getc 3 ,
|
|
.Xr putwc 3 ,
|
|
.Xr stdio 3
|
|
.Sh STANDARDS
|
|
The functions
|
|
.Fn fputc ,
|
|
.Fn putc ,
|
|
and
|
|
.Fn putchar ,
|
|
conform to
|
|
.St -isoC .
|
|
The
|
|
.Fn putc_unlocked
|
|
and
|
|
.Fn putchar_unlocked
|
|
functions conform to
|
|
.St -p1003.1-2001 .
|
|
A function
|
|
.Fn putw
|
|
function appeared in
|
|
.At v6 .
|
|
.Sh BUGS
|
|
The size and byte order of an
|
|
.Vt int
|
|
varies from one machine to another, and
|
|
.Fn putw
|
|
is not recommended for portable applications.
|