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 
file_exist(const char * path)47 static 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 
tst_get_path(const char * prog_name,char * buf,size_t buf_len)57 int 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