[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.
.\" 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 1.16 2007/01/09 00:28:07 imp 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
.Fo fputc
.Fa "int c"
.Fa "FILE *stream"
.Fc
.Ft int
.Fo putc
.Fa "int c"
.Fa "FILE *stream"
.Fc
.Ft int
.Fo putc_unlocked
.Fa "int c"
.Fa "FILE *stream"
.Fc
.Ft int
.Fo putchar
.Fa "int c"
.Fc
.Ft int
.Fo putchar_unlocked
.Fa "int c"
.Fc
.Ft int
.Fo putw
.Fa "int w"
.Fa "FILE *stream"
.Fc
.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.
e9ce8d39 A	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
5b2abdfb	32	.\" @(#)putc.3 8.1 (Berkeley) 6/4/93
1f2f436a	33	.\" $FreeBSD: src/lib/libc/stdio/putc.3,v 1.16 2007/01/09 00:28:07 imp Exp $
e9ce8d39	34	.\"
9385eb3d	35	.Dd January 10, 2003
5b2abdfb	36	.Dt PUTC 3
e9ce8d39 A	37	.Os
e9ce8d39 A	38	.Sh NAME
5b2abdfb A	39	.Nm fputc ,
5b2abdfb A	40	.Nm putc ,
9385eb3d	41	.Nm putc_unlocked ,
5b2abdfb	42	.Nm putchar ,
9385eb3d	43	.Nm putchar_unlocked ,
5b2abdfb A	44	.Nm putw
5b2abdfb A	45	.Nd output a character or word to a stream
e9ce8d39 A	46	.Sh LIBRARY
	47	.Lb libc
	48	.Sh SYNOPSIS
5b2abdfb A	49	.In stdio.h
5b2abdfb A	50	.Ft int
ad3c9f2a A	51	.Fo fputc
	52	.Fa "int c"
	53	.Fa "FILE *stream"
	54	.Fc
5b2abdfb	55	.Ft int
ad3c9f2a A	56	.Fo putc
	57	.Fa "int c"
	58	.Fa "FILE *stream"
	59	.Fc
e9ce8d39	60	.Ft int
ad3c9f2a A	61	.Fo putc_unlocked
	62	.Fa "int c"
	63	.Fa "FILE *stream"
	64	.Fc
9385eb3d	65	.Ft int
ad3c9f2a A	66	.Fo putchar
	67	.Fa "int c"
	68	.Fc
5b2abdfb	69	.Ft int
ad3c9f2a A	70	.Fo putchar_unlocked
	71	.Fa "int c"
	72	.Fc
9385eb3d	73	.Ft int
ad3c9f2a A	74	.Fo putw
	75	.Fa "int w"
	76	.Fa "FILE *stream"
	77	.Fc
e9ce8d39 A	78	.Sh DESCRIPTION
e9ce8d39 A	79	The
5b2abdfb A	80	.Fn fputc
	81	function
	82	writes the character
	83	.Fa c
	84	(converted to an ``unsigned char'')
	85	to the output stream pointed to by
	86	.Fa stream .
	87	.Pp
	88	The
	89	.Fn putc
3d9156a7 A	90	macro acts essentially identically to
	91	.Fn fputc ,
	92	but is a macro that expands in-line.
	93	It may evaluate
	94	.Fa stream
	95	more than once, so arguments given to
	96	.Fn putc
	97	should not be expressions with potential side effects.
5b2abdfb	98	.Pp
e9ce8d39	99	The
5b2abdfb	100	.Fn putchar
9385eb3d	101	function
5b2abdfb A	102	is identical to
	103	.Fn putc
	104	with an output stream of
9385eb3d	105	.Dv stdout .
5b2abdfb A	106	.Pp
	107	The
	108	.Fn putw
	109	function
	110	writes the specified
9385eb3d	111	.Vt int
5b2abdfb A	112	to the named output
5b2abdfb A	113	.Fa stream .
9385eb3d A	114	.Pp
	115	The
	116	.Fn putc_unlocked
	117	and
	118	.Fn putchar_unlocked
	119	functions are equivalent to
	120	.Fn putc
	121	and
	122	.Fn putchar
	123	respectively,
	124	except that the caller is responsible for locking the stream
	125	with
	126	.Xr flockfile 3
	127	before calling them.
	128	These functions may be used to avoid the overhead of locking the stream
	129	for each character, and to avoid output being interspersed from multiple
	130	threads writing to the same stream.
e9ce8d39	131	.Sh RETURN VALUES
5b2abdfb A	132	The functions,
5b2abdfb A	133	.Fn fputc ,
9385eb3d A	134	.Fn putc ,
9385eb3d A	135	.Fn putchar ,
ad3c9f2a	136	.Fn putc_unlocked ,
5b2abdfb	137	and
9385eb3d	138	.Fn putchar_unlocked
5b2abdfb A	139	return the character written.
	140	If an error occurs, the value
	141	.Dv EOF
	142	is returned.
e9ce8d39	143	The
5b2abdfb A	144	.Fn putw
	145	function
	146	returns 0 on success;
	147	.Dv EOF
	148	is returned if
	149	a write error occurs,
	150	or if an attempt is made to write a read-only stream.
	151	.Sh SEE ALSO
	152	.Xr ferror 3 ,
9385eb3d	153	.Xr flockfile 3 ,
5b2abdfb A	154	.Xr fopen 3 ,
5b2abdfb A	155	.Xr getc 3 ,
9385eb3d	156	.Xr putwc 3 ,
5b2abdfb A	157	.Xr stdio 3
	158	.Sh STANDARDS
	159	The functions
	160	.Fn fputc ,
	161	.Fn putc ,
	162	and
	163	.Fn putchar ,
	164	conform to
	165	.St -isoC .
9385eb3d A	166	The
	167	.Fn putc_unlocked
	168	and
	169	.Fn putchar_unlocked
	170	functions conform to
	171	.St -p1003.1-2001 .
5b2abdfb A	172	A function
	173	.Fn putw
	174	function appeared in
	175	.At v6 .
	176	.Sh BUGS
	177	The size and byte order of an
9385eb3d	178	.Vt int
5b2abdfb A	179	varies from one machine to another, and
	180	.Fn putw
	181	is not recommended for portable applications.