cosmopolitan/libc/calls/getcwd.c

62 lines
2.9 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/dce.h"
#include "libc/errno.h"
#include "libc/sysv/errfuns.h"
/**
* Returns current working directory.
*
* @param buf is where UTF-8 NUL-terminated path string gets written,
* which may be NULL to ask this function to malloc a buffer
* @param size is number of bytes available in buf, e.g. PATH_MAX,
* which may be 0 if buf NULL
* @return buf containing system-normative path or NULL w/ errno
* @see get_current_dir_name() which is better
* @error ERANGE, EINVAL
*/
char *(getcwd)(char *buf, size_t size) {
if (buf) {
buf[0] = '\0';
if (!IsWindows()) {
int olderr = errno;
if (getcwd$sysv(buf, size) != NULL) {
return buf;
} else if (IsXnu() && errno == ENOSYS) {
if (size >= 2) {
buf[0] = '.'; /* XXX: could put forth more effort */
buf[1] = '\0';
errno = olderr;
return buf;
} else {
erange();
}
}
return NULL;
} else {
return getcwd$nt(buf, size);
}
} else {
efault();
return NULL;
}
}