dir.c

/*
 * ryshttpd -- simple filesharing http server.
 *
 * ryshttpd is copyrighted:
 * Copyright (C) 2018 Andrey Rys. All rights reserved.
 *
 * ryshttpd is licensed to you under the terms of std. MIT/X11 license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "httpd.h"

char *rh_realpath(const char *path)
{
	char *r, *s, *dir;

	dir = rh_malloc(PATH_MAX);
	s = realpath(path, dir);
	if (!s) {
		pfree(dir);
		return NULL;
	}

	r = rh_strdup(s);
	pfree(dir);
	return r;
}

rh_yesno is_symlink(const char *path)
{
	struct stat st;

	rh_memzero(&st, sizeof(struct stat));
	if (lstat(path, &st) == -1) return NO;
	if (S_ISLNK(st.st_mode)) return YES;
	return NO;
}

int file_or_dir(const char *path)
{
	struct stat st;

	rh_memzero(&st, sizeof(struct stat));
	if (stat(path, &st) == -1) return -1;
	if (S_ISDIR(st.st_mode)) return PATH_IS_DIR;
	/* including symlinks, specials and pseudos */
	return PATH_IS_FILE;
}

rh_yesno is_exec(const char *path)
{
	errno = 0;
	if ((file_or_dir(path) == PATH_IS_FILE) && !errno) {
		if ((access(path, X_OK) == 0) && !errno) return YES;
	}
	return NO;
}

char *rh_which(const char *envpath, const char *name)
{
	char *T, *s, *d, *t;
	const char *p;
	char *r;
	rh_yesno x;

	p = NULL;
	if (envpath == NULL) {
		envpath = rh_getenvline(environ, "PATH=");
		p = envpath+CSTR_SZ("PATH=");
	}
	if (envpath == NULL) return NULL;

	T = rh_strdup(p ? p : envpath);
	s = d = T; t = r = NULL; x = NO;
	while ((s = strtok_r(d, ":", &t))) {
		if (d) d = NULL;

		rh_asprintf(&r, "%s/%s", s, name);
		if (is_exec(r)) {
			x = YES;
			break;
		}
	}

	pfree(T);

	if (x == YES) {
		shrink_dynstr(&r);
		return r;
	}

	pfree(r);
	return NULL;
}