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.Dd January 23, 2020 33.Dt PUTC 3 34.Os 35.Sh NAME 36.Nm fputc , 37.Nm fputc_unlocked , 38.Nm putc , 39.Nm putc_unlocked , 40.Nm putchar , 41.Nm putchar_unlocked , 42.Nm putw 43.Nd output a character or word to a stream 44.Sh LIBRARY 45.Lb libc 46.Sh SYNOPSIS 47.In stdio.h 48.Ft int 49.Fn fputc "int c" "FILE *stream" 50.Ft int 51.Fn fputc_unlocked "int c" "FILE *stream" 52.Ft int 53.Fn putc "int c" "FILE *stream" 54.Ft int 55.Fn putc_unlocked "int c" "FILE *stream" 56.Ft int 57.Fn putchar "int c" 58.Ft int 59.Fn putchar_unlocked "int c" 60.Ft int 61.Fn putw "int w" "FILE *stream" 62.Sh DESCRIPTION 63The 64.Fn fputc 65function 66writes the character 67.Fa c 68(converted to an ``unsigned char'') 69to the output stream pointed to by 70.Fa stream . 71.Pp 72The 73.Fn putc 74macro acts essentially identically to 75.Fn fputc , 76but is a macro that expands in-line. 77It may evaluate 78.Fa stream 79more than once, so arguments given to 80.Fn putc 81should not be expressions with potential side effects. 82.Pp 83The 84.Fn putchar 85function 86is identical to 87.Fn putc 88with an output stream of 89.Dv stdout . 90.Pp 91The 92.Fn putw 93function 94writes the specified 95.Vt int 96to the named output 97.Fa stream . 98.Pp 99The 100.Fn fputc_unlocked , 101.Fn putc_unlocked , 102and 103.Fn putchar_unlocked 104functions are equivalent to 105.Fn fputc , 106.Fn putc , 107and 108.Fn putchar 109respectively, 110except that the caller is responsible for locking the stream 111with 112.Xr flockfile 3 113before calling them. 114These functions may be used to avoid the overhead of locking the stream 115for each character, and to avoid output being interspersed from multiple 116threads writing to the same stream. 117.Sh RETURN VALUES 118The functions, 119.Fn fputc , 120.Fn putc , 121.Fn putchar , 122.Fn putc_unlocked 123and 124.Fn putchar_unlocked 125return the character written. 126If an error occurs, the value 127.Dv EOF 128is returned. 129The 130.Fn putw 131function 132returns 0 on success; 133.Dv EOF 134is returned if 135a write error occurs, 136or if an attempt is made to write a read-only stream. 137.Sh SEE ALSO 138.Xr ferror 3 , 139.Xr flockfile 3 , 140.Xr fopen 3 , 141.Xr getc 3 , 142.Xr putwc 3 , 143.Xr stdio 3 144.Sh STANDARDS 145The functions 146.Fn fputc , 147.Fn putc , 148and 149.Fn putchar , 150conform to 151.St -isoC . 152The 153.Fn putc_unlocked 154and 155.Fn putchar_unlocked 156functions conform to 157.St -p1003.1-2001 . 158A function 159.Fn putw 160function appeared in 161.At v6 . 162.Sh BUGS 163The size and byte order of an 164.Vt int 165varies from one machine to another, and 166.Fn putw 167is not recommended for portable applications. 168