PUTC(3) Library Functions Manual PUTC(3)

fputc, putc, putc_unlocked, putchar, putchar_unlocked, putwoutput a character or word to a stream

Standard C Library (libc, -lc)

#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);

The () function writes the character c (converted to an ``unsigned char'') to the output stream pointed to by stream.

The () 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 () function is identical to putc() with an output stream of stdout.

The () function writes the specified int to the named output stream.

The () and () 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.

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.

ferror(3), flockfile(3), fopen(3), getc(3), putwc(3), stdio(3)

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.

The size and byte order of an int varies from one machine to another, and putw() is not recommended for portable applications.

January 10, 2003 macOS 15.2