minix/lib/stdio/fillbuf.c
2005-04-21 14:53:53 +00:00

69 lines
1.5 KiB
C
Executable file

/*
* fillbuf.c - fill a buffer
*/
/* $Header$ */
#if defined(_POSIX_SOURCE)
#include <sys/types.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include "loc_incl.h"
ssize_t _read(ssize_t d, char *buf, size_t 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++;
}