NAME

putc, putchar, fputc, putw − put character or word on a stream

SYNOPSIS

#include <stdio.h>

int putc (c, stream)
char c;
FILE ∗stream;

putchar (c)

fputc (c, stream)
FILE ∗stream;

putw (w, stream)
int w;
FILE ∗stream;

DESCRIPTION

Putc appends the character c to the named output stream. It returns the character written.

Putchar(c) is defined as putc(c, stdout).

Fputc behaves like putc, but is a genuine function rather than a macro; it may therefore be used as an argument. Fputc runs more slowly than putc, but takes less space per invocation.

Putw appends the word (i.e., integer) w to the output stream. Putw neither assumes nor causes special alignment in the file. 

The standard stream stdout is normally buffered if and only if the output does not refer to a terminal; this default may be changed by setbuf(3S). The standard stream stderr is by default unbuffered unconditionally, but use of freopen(3S) will cause it to become unbuffered; setbuf, again, will set the state to whatever is desired. When an output stream is unbuffered information appears on the destination file or terminal as soon as written; when it is buffered many characters are saved up and written as a block. See also fflush(3S).

SEE ALSO

ferror(3S), fopen(3S), fwrite(3S), getc(3S), printf(3S), puts(3S). 

DIAGNOSTICS

These functions return the constant EOF upon error.  Since this is a good integer, ferror(3S) should be used to detect putw errors. 

BUGS

Because it is implemented as a macro, putc treats incorrectly a stream argument with side effects.  In particular, putc(c, ∗f++); doesn’t work sensibly. 

May 16, 1980