cosmopolitan/libc/calls/hefty/get_current_dir_name.c

41 lines
2.5 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 │
│ │
│ 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/bits/safemacros.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/calls/calls.h"
#include "libc/sysv/errfuns.h"
/**
* Returns current working directory.
*
* If the PWD environment variable is set, that'll be returned (since
* it's faster than issuing a system call).
*
* @return pointer that must be free()'d, or NULL w/ errno
*/
nodiscard char *get_current_dir_name(void) {
char *buf, *res;
if ((res = getenv("PWD"))) return strdup(res);
if (!(buf = malloc(PATH_MAX))) return NULL;
if (!(res = (getcwd)(buf, PATH_MAX))) free(buf);
return res;
}