NAME    [Toc]    [Back]

     ungetc - un-get character from input stream

SYNOPSIS    [Toc]    [Back]

     #include <stdio.h>

     int
     ungetc(int c, FILE *stream);

DESCRIPTION    [Toc]    [Back]

     The ungetc() function pushes the character c  (converted  to
an unsigned
     char)  back onto the input stream pointed to by stream.  The
pushed-backed
     characters will be  returned  by  subsequent  reads  on  the
stream (in reverse
     order).   A  successful  intervening  call,  using  the same
stream, to one of
     the file positioning  functions  (fseek(3),  fsetpos(3),  or
rewind(3)) will
     discard the pushed back characters.

     One  character  of  push-back  is guaranteed, but as long as
there is sufficient
 memory, an effectively infinite amount of pushback  is
allowed.

     If  a character is successfully pushed-back, the end-of-file
indicator for
     the stream is cleared.

RETURN VALUES    [Toc]    [Back]

     The ungetc() function returns the character pushed-back  after the conversion,
  or  EOF  if the operation fails.  If the value of the
argument c
     character equals EOF, the operation will fail and the stream
will remain
     unchanged.

SEE ALSO    [Toc]    [Back]

     fseek(3), getc(3), setvbuf(3)

STANDARDS    [Toc]    [Back]

     The  ungetc()  function conforms to ANSI X3.159-1989 (``ANSI
C'').

OpenBSD      3.6                           June      4,      1993