1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 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.\" 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. 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.\" 32.\" @(#)putc.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/stdio/putc.3,v 1.16 2007/01/09 00:28:07 imp Exp $ 34.\" $DragonFly: src/lib/libc/stdio/putc.3,v 1.2 2003/06/17 04:26:46 dillon Exp $ 35.\" 36.Dd March 22, 2009 37.Dt PUTC 3 38.Os 39.Sh NAME 40.Nm fputc , 41.Nm putc , 42.Nm putc_unlocked , 43.Nm putchar , 44.Nm putchar_unlocked , 45.Nm putw 46.Nd output a character or word to a stream 47.Sh LIBRARY 48.Lb libc 49.Sh SYNOPSIS 50.In stdio.h 51.Ft int 52.Fn fputc "int c" "FILE *stream" 53.Ft int 54.Fn putc "int c" "FILE *stream" 55.Ft int 56.Fn putc_unlocked "int c" "FILE *stream" 57.Ft int 58.Fn putchar "int c" 59.Ft int 60.Fn putchar_unlocked "int c" 61.Ft int 62.Fn putw "int w" "FILE *stream" 63.Sh DESCRIPTION 64The 65.Fn fputc 66function 67writes the character 68.Fa c 69(converted to an ``unsigned char'') 70to the output stream pointed to by 71.Fa stream . 72.Pp 73The 74.Fn putc 75macro acts essentially identically to 76.Fn fputc , 77but is a macro that expands in-line. 78It may evaluate 79.Fa stream 80more than once, so arguments given to 81.Fn putc 82should not be expressions with potential side effects. 83.Pp 84The 85.Fn putchar 86function 87is identical to 88.Fn putc 89with an output stream of 90.Dv stdout . 91.Pp 92The 93.Fn putw 94function 95writes the specified 96.Vt int 97to the named output 98.Fa stream . 99.Pp 100The 101.Fn putc_unlocked 102and 103.Fn putchar_unlocked 104functions are equivalent to 105.Fn putc 106and 107.Fn putchar 108respectively, 109except that the caller is responsible for locking the stream 110with 111.Xr flockfile 3 112before calling them. 113These functions may be used to avoid the overhead of locking the stream 114for each character, and to avoid output being interspersed from multiple 115threads writing to the same stream. 116.Sh RETURN VALUES 117The functions, 118.Fn fputc , 119.Fn putc , 120.Fn putchar , 121.Fn putc_unlocked 122and 123.Fn putchar_unlocked 124return the character written. 125If an error occurs, the value 126.Dv EOF 127is returned. 128The 129.Fn putw 130function 131returns 0 on success; 132.Dv EOF 133is returned if 134a write error occurs, 135or if an attempt is made to write a read-only stream. 136.Sh SEE ALSO 137.Xr ferror 3 , 138.Xr flockfile 3 , 139.Xr fopen 3 , 140.Xr getc 3 , 141.Xr putwc 3 , 142.Xr stdio 3 143.Sh STANDARDS 144The functions 145.Fn fputc , 146.Fn putc , 147and 148.Fn putchar , 149conform to 150.St -isoC . 151The 152.Fn putc_unlocked 153and 154.Fn putchar_unlocked 155functions conform to 156.St -p1003.1-2001 . 157A function 158.Fn putw 159function appeared in 160.At v6 . 161.Sh BUGS 162The size and byte order of an 163.Vt int 164varies from one machine to another, and 165.Fn putw 166is not recommended for portable applications. 167