4.3BSD - /usr/man/cat3/ungetc.0

UNGETC(3S)                                                          UNGETC(3S)


NAME
       ungetc - push character back into input stream

SYNOPSIS
       #include <stdio.h>

       ungetc(c, stream)
       FILE *stream;

DESCRIPTION
       Ungetc  pushes the character c 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) erases all memory of pushed back characters.

SEE ALSO
       getc(3S), setbuf(3S), fseek(3S)

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


7th Edition                      May 15, 1985                       UNGETC(3S)