xref: /freebsd/lib/libc/stdio/putc.3 (revision c24891e9e29efd394a35e48062b9dbda31bc8359)

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.\"     @(#)putc.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd January 10, 2003
.Dt PUTC 3
.Os
.Sh NAME
.Nm fputc ,
.Nm putc ,
.Nm putchar ,
.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
function acts essentially identically to
.Fn fputc .
.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
.Fn flockfile
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.