ack/lang/cem/libcc.ansi/stdio/ungetc.c
1989-05-30 13:34:25 +00:00

25 lines
454 B
C

/*
* ungetc.c - push a character back onto an imput stream
*/
/* $Header$ */
#include <stdio.h>
#include "loc_incl.h"
int
ungetc(int ch, FILE *stream)
{
unsigned char *p;
if (ch == EOF || !io_testflag(stream,_IOREAD))
return EOF;
if (stream->_ptr == stream->_buf) {
if (stream->_count != 0) return EOF;
stream->_ptr++;
}
stream->_count++;
p = --(stream->_ptr); /* ??? Bloody vax assembler !!! */
*p = (unsigned char) ch;
return ch;
}