Name

ungetc − push character back into input stream

Syntax

#include <stdio.h>

ungetc(c, stream)
FILE *stream;

Description

The ungetc routine pushes the character c back on an input stream.  That character will be returned by the next getc call on that stream.  The ungetc routine returns c.  One character of pushback is guaranteed in all cases. 

The fseek() routine erases all memory of pushed back characters.

Diagnostics

The ungetc routine returns EOF if it cannot push a character back.

Environment

In POSIX mode, the file’s EOF indicator is cleared. 

See Also

fseek(3s), getc(3s), setbuf(3s)