cosmopolitan/libc/stdio/fdopen.c

54 lines
2.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/mem/mem.h"
#include "libc/stdio/internal.h"
#include "libc/stdio/stdio.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/errfuns.h"
/**
* Allocates stream object for already-opened file descriptor.
*
* @param fd existing file descriptor or -1 for plain old buffer
* @param mode is passed to fopenflags()
* @return new stream or NULL w/ errno
* @error ENOMEM
*/
FILE *fdopen(int fd, const char *mode) {
FILE *f;
if ((f = calloc(1, sizeof(FILE)))) {
f->fd = fd;
f->reader = __freadbuf;
f->writer = __fwritebuf;
f->bufmode = ischardev(fd) ? _IOLBF : _IOFBF;
f->iomode = fopenflags(mode);
f->size = BUFSIZ;
if ((f->buf = valloc(f->size))) {
if ((f->iomode & O_ACCMODE) != O_RDONLY) {
_fflushregister(f);
}
return f;
}
free(f);
}
return NULL;
}