MirBSD manpage: ungetc(3)

UNGETC(3)                  BSD 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 char-
     acter equals EOF, the operation will fail and the stream will remain un-
     changed.

SEE ALSO

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

STANDARDS

     The ungetc() function conforms to ANSI X3.159-1989 ("ANSI C89").

MirBSD #10-current               June 4, 1993                                1