ack/lang/cem/libcc.ansi/stdio/fillbuf.c
1994-06-24 14:02:31 +00:00

71 lines
1.4 KiB
C

/*
* fillbuf.c - fill a buffer
*/
/* $Id$ */
#include <stdio.h>
#include <stdlib.h>
#include "loc_incl.h"
int _read(int d, char *buf, int nbytes);
int
__fillbuf(register FILE *stream)
{
static unsigned char ch[FOPEN_MAX];
register int i;
stream->_count = 0;
if (fileno(stream) < 0) return EOF;
if (io_testflag(stream, (_IOEOF | _IOERR ))) return EOF;
if (!io_testflag(stream, _IOREAD)) {
stream->_flags |= _IOERR;
return EOF;
}
if (io_testflag(stream, _IOWRITING)) {
stream->_flags |= _IOERR;
return EOF;
}
if (!io_testflag(stream, _IOREADING))
stream->_flags |= _IOREADING;
if (!io_testflag(stream, _IONBF) && !stream->_buf) {
stream->_buf = (unsigned char *) malloc(BUFSIZ);
if (!stream->_buf) {
stream->_flags |= _IONBF;
}
else {
stream->_flags |= _IOMYBUF;
stream->_bufsiz = BUFSIZ;
}
}
/* flush line-buffered output when filling an input buffer */
for (i = 0; i < FOPEN_MAX; i++) {
if (__iotab[i] && io_testflag(__iotab[i], _IOLBF))
if (io_testflag(__iotab[i], _IOWRITING))
(void) fflush(__iotab[i]);
}
if (!stream->_buf) {
stream->_buf = &ch[fileno(stream)];
stream->_bufsiz = 1;
}
stream->_ptr = stream->_buf;
stream->_count = _read(stream->_fd, (char *)stream->_buf, stream->_bufsiz);
if (stream->_count <= 0){
if (stream->_count == 0) {
stream->_flags |= _IOEOF;
}
else
stream->_flags |= _IOERR;
return EOF;
}
stream->_count--;
return *stream->_ptr++;
}