1/*
2 * Copyright (C) 2010 Cyril Hrubis chrubis@suse.cz
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like.  Any license provided herein, whether implied or
15 * otherwise, applies only to this software file.  Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 */
23
24 /*
25  * Looks for binary prog_name in $PATH.
26  *
27  * If such file exists and if you are able at least to read it, zero is
28  * returned and absolute path to the file is filled into buf. In case buf is
29  * too short to hold the absolute path + prog_name for the file we are looking
30  * for -1 is returned as well as when there is no such file in all paths in
31  * $PATH.
32  */
33
34#include "test.h"
35
36#include <stdio.h>
37#include <string.h>
38#include <stdlib.h>
39#include <unistd.h>
40#include <sys/types.h>
41#include <sys/stat.h>
42
43#ifndef MIN
44#define MIN(a, b) ((a)<(b)?(a):(b))
45#endif
46
47static int file_exist(const char *path)
48{
49	struct stat st;
50
51	if (!access(path, R_OK) && !stat(path, &st) && S_ISREG(st.st_mode))
52		return 1;
53
54	return 0;
55}
56
57int tst_get_path(const char *prog_name, char *buf, size_t buf_len)
58{
59	const char *path = (const char *)getenv("PATH");
60	const char *start = path;
61	const char *end;
62	size_t size, ret;
63
64	if (path == NULL)
65		return -1;
66
67	do {
68		end = strchr(start, ':');
69
70		if (end != NULL)
71			snprintf(buf, MIN(buf_len, (size_t) (end - start + 1)),
72				 "%s", start);
73		else
74			snprintf(buf, buf_len, "%s", start);
75
76		size = strlen(buf);
77
78		/*
79		 * "::" inside $PATH, $PATH ending with ':' or $PATH starting
80		 * with ':' should be expanded into current working directory.
81		 */
82		if (size == 0) {
83			snprintf(buf, buf_len, ".");
84			size = strlen(buf);
85		}
86
87		/*
88		 * If there is no '/' ad the end of path from $PATH add it.
89		 */
90		if (buf[size - 1] != '/')
91			ret =
92			    snprintf(buf + size, buf_len - size, "/%s",
93				     prog_name);
94		else
95			ret =
96			    snprintf(buf + size, buf_len - size, "%s",
97				     prog_name);
98
99		if (buf_len - size > ret && file_exist(buf))
100			return 0;
101
102		start = end + 1;
103
104	} while (end != NULL);
105
106	return -1;
107}
108