UNGETC(3S)                           SysV                           UNGETC(3S)



NAME
     ungetc - push character back into input stream

SYNOPSIS
     #include <stdio.h>

     int ungetc (c, stream)
     int c;
     FILE *stream;

DESCRIPTION
     ungetc inserts the character c into the buffer associated with an input
     stream.  That character, c, will be returned by the next getc(3S) call on
     that stream.  ungetc returns c, and leaves the file stream unchanged.

     One character of pushback is guaranteed, provided something has already
     been read from the stream and the stream is actually buffered.

     If c equals EOF, ungetc does nothing to the buffer and returns EOF.

     fseek(3S) erases all memory of inserted characters.

     Note that if ungetc is called after reaching EOF, the EOF indicator on
     the stream is now cleared.

SEE ALSO
     Fseek(3S), getc(3S), setbuf(3S), stdio(3S).

DIAGNOSTICS
     ungetc returns EOF if it cannot insert the character.

BUGS
     When stream is stdin, one character may be pushed back onto the buffer
     without a previous read statement.