PUTC(3) Library Functions Manual PUTC(3)
NAME
putc — put byte on
a stream
SYNOPSIS
#include <stdio.h> int putc(int c, FILE *stream);
DESCRIPTION
The putc() function is 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
Because it may be implemented as a macro, putc() may treat a
stream argument with side-effects incorrectly. In particular,
putc ( c , * f ++) will not necessarily work
correctly. Therefore, use of this interface is not recommended in such
situations; fputc(3) should be used instead.
FUTURE DIRECTIONS
None.
SEE ALSO
DERIVATION
Derived from Issue 1 of the SVID.
February 1997 posix.fail