NAME
fputc, putc,
putc_unlocked, putchar,
putchar_unlocked, putw
— output a character or word to
a stream
LIBRARY
library “libc”
SYNOPSIS
#include
<stdio.h>
int
fputc(int
c, FILE
*stream);
int
putc(int
c, FILE
*stream);
int
putc_unlocked(int
c, FILE
*stream);
int
putchar(int
c);
int
putchar_unlocked(int
c);
int
putw(int
w, FILE
*stream);
DESCRIPTION
Thefputc()
function writes the character c (converted to an
``unsigned char'') to the output stream pointed to by
stream.
The
putc() macro
acts essentially identically to fputc(), but is a
macro that expands in-line. It may evaluate stream
more than once, so arguments given to putc() should
not be expressions with potential side effects.
The
putchar()
function is identical to putc() with an output
stream of stdout.
The
putw()
function writes the specified int to the named output
stream.
The
putc_unlocked()
and
putchar_unlocked()
functions are equivalent to putc() and
putchar() respectively, except that the caller is
responsible for locking the stream with
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.
RETURN VALUES
The functions, fputc(),
putc(), putchar(),
putc_unlocked() and
putchar_unlocked() return the character written. If
an error occurs, the value EOF is returned. The
putw() function returns 0 on success;
EOF is returned if a write error occurs, or if an
attempt is made to write a read-only stream.
SEE ALSO
ferror(3), flockfile(3), fopen(3), getc(3), putwc(3), stdio(3)
STANDARDS
The functions fputc(),
putc(), and putchar(),
conform to ISO/IEC 9899:1990
(“ISO C90”). The
putc_unlocked() and
putchar_unlocked() functions conform to
IEEE Std 1003.1-2001 (“POSIX.1”). A
function putw() function appeared in
Version 6 AT&T UNIX.
BUGS
The size and byte order of an int varies
from one machine to another, and putw() is not
recommended for portable applications.