putc
[write a character (macro)]
SYNOPSIS
#include
<stdio.h>
int putc(int
ch, FILE
*fp);
DESCRIPTION
putc
is a macro, defined in stdio.h.
putc
writes the argument, ch,
to the file or stream identified by
fp,
after converting it from an int
to an unsigned
char.
If the file was opened with append mode (or if the stream cannot support positioning), then the new character goes at the end of the file or stream. Otherwise, the new character is written at the current value of the position indicator, and the position indicator advances by one.
For a subroutine version of this macro, see fputc.
RETURNS
If successful, putc
returns its argument, ch.
If an error intervenes, the result is EOF.
You can use ferror(fp)
to query for errors.
COMPLIANCE
ANSI C requires
by putc;
it suggests, but does not require, that putc
be implemented as a macro. The standard
explicitly permits macro implementations of putc
to use the fp
argument more than once; therefore,
in a portable program, you should not use an expression with side effects
as this argument.
Supporting OS subroutines required: close, fstat, isatty, lseek, read, sbrk, write.
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