ack/lang/cem/libcc.ansi/sys/stdio/fillbuf.c
David Given 9109d7af7f First stage in modularising FILE*. Refactor so that printf/scanf don't rely on
FILE* innards; allow plats to replace the entire emulated FILE* system.
2019-06-15 13:07:10 +02:00

84 lines
1.5 KiB
C

/*
* fillbuf.c - fill a buffer
*/
/* $Id$ */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "loc_incl.h"
#if ACKCONF_WANT_STDIO && ACKCONF_WANT_EMULATED_FILE
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))
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++;
}
#endif