UNGETC(3)                 OpenBSD Programmer's Manual                UNGETC(3)

NAME
     ungetc - un-get character from input stream



SYNOPSIS
     #include <stdio.h>

     int
     ungetc(int c, FILE *stream);

DESCRIPTION
     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 suffi-
     cient 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
     The ungetc() function returns the character pushed-back after the conver-
     sion, 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
     fseek(3),  getc(3),  setvbuf(3)

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

OpenBSD 2.6                      June 4, 1993                                1