.\"	$OpenBSD: putc.3,v 1.10 2007/05/31 19:19:31 jmc Exp $
.\"
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.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
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.Dd $Mdocdate: May 31 2007 $
.Dt PUTC 3
.Os
.Sh NAME
.Nm fputc ,
.Nm putc ,
.Nm putchar ,
.Nm putw
.Nd output a character or word to a stream
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Ft int
.Fn fputc "int c" "FILE *stream"
.Ft int
.Fn putc "int c" "FILE *stream"
.Ft int
.Fn putchar "int c"
.Ft int
.Fn putw "int w" "FILE *stream"
.Sh DESCRIPTION
The
.Fn fputc
function writes the character
.Fa c
(converted to an
.Li unsigned char )
to the output stream pointed to by
.Fa stream .
.Pp
.Fn putc
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
.Fn putchar
is identical to
.Fn putc
with an output stream of
.Em stdout .
.Pp
The
.Fn putw
function writes the specified
.Li int
.Fa w
to the named output
.Fa stream .
.Sh RETURN VALUES
The functions
.Fn fputc ,
.Fn putc ,
and
.Fn putchar
return the character written.
If an error occurs, the value
.Dv EOF
is returned and the global variable
.Va errno
is set to indicate the error.
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.
The global variable
.Va errno
may be set to indicate the error.
.Sh ERRORS
The function
.Fn putw
may also fail and set
.Va errno
for any of the errors specified for the routines
.Xr write 2
or
.Xr realloc 3 .
.Sh SEE ALSO
.Xr ferror 3 ,
.Xr fopen 3 ,
.Xr getc 3 ,
.Xr stdio 3
.Sh STANDARDS
The functions
.Fn fputc ,
.Fn putc ,
and
.Fn putchar ,
conform to
.St -ansiC .
A function
.Fn putw
function appeared in
.At v6 .
.Sh BUGS
Since the size and byte order of an
.Li int
may vary from one machine to another,
.Fn putw
is not recommended for portable applications.