[apple/libc.git] / stdio / FreeBSD / putc.3

.\" 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. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 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.
.\"
.\"     @(#)putc.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/stdio/putc.3,v 1.15 2004/03/17 12:46:17 tjr Exp $
.\"
.Dd January 10, 2003
.Dt PUTC 3
.Os
.Sh NAME
.Nm fputc ,
.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 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 putc_unlocked
and
.Fn putchar_unlocked
functions are equivalent to
.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.
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1990, 1991, 1993
e9ce8d39 A	2	.\" The Regents of the University of California. All rights reserved.
e9ce8d39 A	3	.\"
5b2abdfb A	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" Chris Torek and the American National Standards Committee X3,
	6	.\" on Information Processing Systems.
	7	.\"
e9ce8d39 A	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
	16	.\" 3. All advertising materials mentioning features or use of this software
	17	.\" must display the following acknowledgement:
	18	.\" This product includes software developed by the University of
	19	.\" California, Berkeley and its contributors.
	20	.\" 4. Neither the name of the University nor the names of its contributors
	21	.\" may be used to endorse or promote products derived from this software
	22	.\" without specific prior written permission.
	23	.\"
	24	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	.\" SUCH DAMAGE.
	35	.\"
5b2abdfb	36	.\" @(#)putc.3 8.1 (Berkeley) 6/4/93
3d9156a7	37	.\" $FreeBSD: src/lib/libc/stdio/putc.3,v 1.15 2004/03/17 12:46:17 tjr Exp $
e9ce8d39	38	.\"
9385eb3d	39	.Dd January 10, 2003
5b2abdfb	40	.Dt PUTC 3
e9ce8d39 A	41	.Os
e9ce8d39 A	42	.Sh NAME
5b2abdfb A	43	.Nm fputc ,
5b2abdfb A	44	.Nm putc ,
9385eb3d	45	.Nm putc_unlocked ,
5b2abdfb	46	.Nm putchar ,
9385eb3d	47	.Nm putchar_unlocked ,
5b2abdfb A	48	.Nm putw
5b2abdfb A	49	.Nd output a character or word to a stream
e9ce8d39 A	50	.Sh LIBRARY
	51	.Lb libc
	52	.Sh SYNOPSIS
5b2abdfb A	53	.In stdio.h
	54	.Ft int
	55	.Fn fputc "int c" "FILE *stream"
	56	.Ft int
	57	.Fn putc "int c" "FILE *stream"
e9ce8d39	58	.Ft int
9385eb3d A	59	.Fn putc_unlocked "int c" "FILE *stream"
9385eb3d A	60	.Ft int
5b2abdfb A	61	.Fn putchar "int c"
5b2abdfb A	62	.Ft int
9385eb3d A	63	.Fn putchar_unlocked "int c"
9385eb3d A	64	.Ft int
5b2abdfb	65	.Fn putw "int w" "FILE *stream"
e9ce8d39 A	66	.Sh DESCRIPTION
e9ce8d39 A	67	The
5b2abdfb A	68	.Fn fputc
	69	function
	70	writes the character
	71	.Fa c
	72	(converted to an ``unsigned char'')
	73	to the output stream pointed to by
	74	.Fa stream .
	75	.Pp
	76	The
	77	.Fn putc
3d9156a7 A	78	macro acts essentially identically to
	79	.Fn fputc ,
	80	but is a macro that expands in-line.
	81	It may evaluate
	82	.Fa stream
	83	more than once, so arguments given to
	84	.Fn putc
	85	should not be expressions with potential side effects.
5b2abdfb	86	.Pp
e9ce8d39	87	The
5b2abdfb	88	.Fn putchar
9385eb3d	89	function
5b2abdfb A	90	is identical to
	91	.Fn putc
	92	with an output stream of
9385eb3d	93	.Dv stdout .
5b2abdfb A	94	.Pp
	95	The
	96	.Fn putw
	97	function
	98	writes the specified
9385eb3d	99	.Vt int
5b2abdfb A	100	to the named output
5b2abdfb A	101	.Fa stream .
9385eb3d A	102	.Pp
	103	The
	104	.Fn putc_unlocked
	105	and
	106	.Fn putchar_unlocked
	107	functions are equivalent to
	108	.Fn putc
	109	and
	110	.Fn putchar
	111	respectively,
	112	except that the caller is responsible for locking the stream
	113	with
	114	.Xr flockfile 3
	115	before calling them.
	116	These functions may be used to avoid the overhead of locking the stream
	117	for each character, and to avoid output being interspersed from multiple
	118	threads writing to the same stream.
e9ce8d39	119	.Sh RETURN VALUES
5b2abdfb A	120	The functions,
5b2abdfb A	121	.Fn fputc ,
9385eb3d A	122	.Fn putc ,
	123	.Fn putchar ,
	124	.Fn putc_unlocked
5b2abdfb	125	and
9385eb3d	126	.Fn putchar_unlocked
5b2abdfb A	127	return the character written.
	128	If an error occurs, the value
	129	.Dv EOF
	130	is returned.
e9ce8d39	131	The
5b2abdfb A	132	.Fn putw
	133	function
	134	returns 0 on success;
	135	.Dv EOF
	136	is returned if
	137	a write error occurs,
	138	or if an attempt is made to write a read-only stream.
	139	.Sh SEE ALSO
	140	.Xr ferror 3 ,
9385eb3d	141	.Xr flockfile 3 ,
5b2abdfb A	142	.Xr fopen 3 ,
5b2abdfb A	143	.Xr getc 3 ,
9385eb3d	144	.Xr putwc 3 ,
5b2abdfb A	145	.Xr stdio 3
	146	.Sh STANDARDS
	147	The functions
	148	.Fn fputc ,
	149	.Fn putc ,
	150	and
	151	.Fn putchar ,
	152	conform to
	153	.St -isoC .
9385eb3d A	154	The
	155	.Fn putc_unlocked
	156	and
	157	.Fn putchar_unlocked
	158	functions conform to
	159	.St -p1003.1-2001 .
5b2abdfb A	160	A function
	161	.Fn putw
	162	function appeared in
	163	.At v6 .
	164	.Sh BUGS
	165	The size and byte order of an
9385eb3d	166	.Vt int
5b2abdfb A	167	varies from one machine to another, and
	168	.Fn putw
	169	is not recommended for portable applications.