NAME

ungetc − push character back into input stream

SYNOPSIS

#include <stdio.h>

int ungetc(int c, FILE ∗stream)

DESCRIPTION

Ungetc pushes the character c (converted to an unsigned char) back on an input stream.  That character will be returned by the next getc call on that stream.  Ungetc returns c.

One character of pushback is guaranteed provided something has been read from the stream and the stream is actually buffered.  Attempts to push EOF are rejected. 

Fseek(3S), fsetpos(3S), or rewind(3S) erases all memory of pushed back characters.

SEE ALSO

getc(3S), setbuf(3S), fseek(3S), fsetpos(3S), rewind(3S)

DIAGNOSTICS

Ungetc returns EOF if it can’t push a character back. 

ANSI C  —  June 23, 1989