cosmopolitan/libc/calls/fstatat.c

49 lines
2.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/errno.h"
#include "libc/sysv/consts/at.h"
/**
* Performs stat() w/ features for threaded apps.
*
* @param dirfd can be AT_FDCWD or an open directory descriptor, and is
* ignored if pathname is absolute
* @param flags can have AT_{EMPTY_PATH,NO_AUTOMOUNT,SYMLINK_NOFOLLOW}
* @return 0 on success, or -1 w/ errno
* @asyncsignalsafe
*/
int fstatat(int dirfd, const char *pathname, struct stat *st, uint32_t flags) {
int olderr = errno;
int rc = fstatat$sysv(dirfd, pathname, st, flags);
if (rc != -1) {
stat2linux(st);
} else if (errno == ENOSYS && dirfd == AT_FDCWD) {
if (!flags) {
errno = olderr;
rc = stat(pathname, st);
} else if (flags == AT_SYMLINK_NOFOLLOW) {
errno = olderr;
rc = lstat(pathname, st);
}
}
return rc;
}