NAME
putc — put a byte
on a stream
SYNOPSIS
#include
<stdio.h>
int putc(int c, FILE *stream);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2017 defers to the ISO C standard.
The putc () function shall be equivalent
to fputc(3), except that if it is implemented as a macro
it may evaluate stream more than once, so the argument
should never be an expression with side-effects.
RETURN VALUE
Refer to fputc(3).
ERRORS
Refer to fputc(3).
EXAMPLES
None.
APPLICATION USAGE
Since it may be implemented as a macro,
putc () may treat a stream
argument with side-effects incorrectly. In particular,
putc (
c, *
f ++) does not
necessarily work correctly. Therefore, use of this function is not
recommended in such situations; fputc(3) should be used
instead.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD <stdio.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 7
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0470 [14] is applied.