minix/lib/libc/stdio/flushbuf.c

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2005-04-21 16:53:53 +02:00
/*
* flushbuf.c - flush a buffer
*/
/* $Id$ */
#include <stdio.h>
#include <stdlib.h>
#include "loc_incl.h"
#include <sys/types.h>
off_t _lseek(int fildes, off_t offset, int whence);
ssize_t _write(int d, const char *buf, int nbytes);
int _isatty(int d);
extern void (*_clean)(void);
static int
do_write(int d, char *buf, int nbytes)
{
int c;
/* POSIX actually allows write() to return a positive value less
than nbytes, so loop ...
*/
while ((c = _write(d, buf, nbytes)) > 0 && c < nbytes) {
nbytes -= c;
buf += c;
}
return c > 0;
}
int
__flushbuf(int c, FILE * stream)
{
_clean = __cleanup;
if (fileno(stream) < 0) return (unsigned char) c;
if (!io_testflag(stream, _IOWRITE)) return EOF;
if (io_testflag(stream, _IOREADING) && !feof(stream)) return EOF;
stream->_flags &= ~_IOREADING;
stream->_flags |= _IOWRITING;
if (!io_testflag(stream, _IONBF)) {
if (!stream->_buf) {
if (stream == stdout && _isatty(fileno(stdout))) {
if (!(stream->_buf =
(unsigned char *) malloc(BUFSIZ))) {
stream->_flags |= _IONBF;
} else {
stream->_flags |= _IOLBF|_IOMYBUF;
stream->_bufsiz = BUFSIZ;
stream->_count = -1;
}
} else {
if (!(stream->_buf =
(unsigned char *) malloc(BUFSIZ))) {
stream->_flags |= _IONBF;
} else {
stream->_flags |= _IOMYBUF;
stream->_bufsiz = BUFSIZ;
if (!io_testflag(stream, _IOLBF))
stream->_count = BUFSIZ - 1;
else stream->_count = -1;
}
}
stream->_ptr = stream->_buf;
}
}
if (io_testflag(stream, _IONBF)) {
char c1 = c;
stream->_count = 0;
if (io_testflag(stream, _IOAPPEND)) {
if (_lseek(fileno(stream), 0L, SEEK_END) == -1) {
stream->_flags |= _IOERR;
return EOF;
}
}
if (_write(fileno(stream), &c1, 1) != 1) {
stream->_flags |= _IOERR;
return EOF;
}
return (unsigned char) c;
} else if (io_testflag(stream, _IOLBF)) {
*stream->_ptr++ = c;
/* stream->_count has been updated in putc macro. */
if (c == '\n' || stream->_count == -stream->_bufsiz) {
int count = -stream->_count;
stream->_ptr = stream->_buf;
stream->_count = 0;
if (io_testflag(stream, _IOAPPEND)) {
if (_lseek(fileno(stream), 0L, SEEK_END) == -1) {
stream->_flags |= _IOERR;
return EOF;
}
}
if (! do_write(fileno(stream), (char *)stream->_buf,
count)) {
stream->_flags |= _IOERR;
return EOF;
}
}
} else {
int count = stream->_ptr - stream->_buf;
stream->_count = stream->_bufsiz - 1;
stream->_ptr = stream->_buf + 1;
if (count > 0) {
if (io_testflag(stream, _IOAPPEND)) {
if (_lseek(fileno(stream), 0L, SEEK_END) == -1) {
stream->_flags |= _IOERR;
return EOF;
}
}
if (! do_write(fileno(stream), (char *)stream->_buf, count)) {
*(stream->_buf) = c;
stream->_flags |= _IOERR;
return EOF;
}
}
*(stream->_buf) = c;
}
return (unsigned char) c;
}