posix-io/access.c

/*	A part of the Windows CE C Extra Library (celibc)
	Copyright 2007-2015 PC GO Ld.

	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; either version 2 of the License, or (at your option) any later version.

	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.
*/

#include <unistd.h>
#include <sys/stat.h>
#include <errno.h>

int access(const char *pathname, int mode) {
	if(mode & ~(R_OK | W_OK | X_OK | F_OK)) {
		errno = EINVAL;
		return -1;
	}
	if(!pathname) {
		errno = EFAULT;
		return -1;
	}
	if(!*pathname) {
		errno = ENOENT;
		return -1;
	}

	struct stat st;
	if(stat(pathname, &st) < 0) return -1;

	if((mode & W_OK) && !(st.st_mode & S_IWRITE)) {
		errno = EACCES;
		return -1;
	}

	return 0;
}