xref: /titanic_41/usr/src/lib/libast/common/path/pathpath.c (revision 9e86db79b7d1bbc5f2f04e99954cbd5eae0e22bb)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2008 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24  * Glenn Fowler
25  * AT&T Research
26  *
27  * return full path to p with mode access using $PATH
28  * a!=0 enables related root search
29  * a!=0 && a!="" searches a dir first
30  * the related root must have a bin subdir
31  * p==0 sets the cached relative dir to a
32  * full path returned in path buffer
33  * if path==0 then the space is malloc'd
34  */
35 
36 #include <ast.h>
37 
38 char*
39 pathpath(register char* path, const char* p, const char* a, int mode)
40 {
41 	register char*	s;
42 	char*		x;
43 	char		buf[PATH_MAX];
44 
45 	static char*	cmd;
46 
47 	if (!path)
48 		path = buf;
49 	if (!p)
50 	{
51 		if (cmd)
52 			free(cmd);
53 		cmd = a ? strdup(a) : (char*)0;
54 		return 0;
55 	}
56 	if (strlen(p) < PATH_MAX)
57 	{
58 		strcpy(path, p);
59 		if (pathexists(path, mode))
60 		{
61 			if (*p != '/' && (mode & PATH_ABSOLUTE))
62 			{
63 				getcwd(buf, sizeof(buf));
64 				s = buf + strlen(buf);
65 				sfsprintf(s, sizeof(buf) - (s - buf), "/%s", p);
66 				if (path != buf)
67 					strcpy(path, buf);
68 			}
69 			return (path == buf) ? strdup(path) : path;
70 		}
71 	}
72 	if (*p == '/')
73 		a = 0;
74 	else if (s = (char*)a)
75 	{
76 		x = s;
77 		if (strchr(p, '/'))
78 		{
79 			a = p;
80 			p = "..";
81 		}
82 		else
83 			a = 0;
84 		if ((!cmd || *cmd) && (strchr(s, '/') || (s = cmd)))
85 		{
86 			if (!cmd && *s == '/')
87 				cmd = strdup(s);
88 			if (strlen(s) < (sizeof(buf) - 6))
89 			{
90 				s = strcopy(path, s);
91 				for (;;)
92 				{
93 					do if (s <= path) goto normal; while (*--s == '/');
94 					do if (s <= path) goto normal; while (*--s != '/');
95 					strcpy(s + 1, "bin");
96 					if (pathexists(path, PATH_EXECUTE))
97 					{
98 						if (s = pathaccess(path, path, p, a, mode))
99 							return path == buf ? strdup(s) : s;
100 						goto normal;
101 					}
102 				}
103 			normal: ;
104 			}
105 		}
106 	}
107 	x = !a && strchr(p, '/') ? "" : pathbin();
108 	if (!(s = pathaccess(path, x, p, a, mode)) && !*x && (x = getenv("FPATH")))
109 		s = pathaccess(path, x, p, a, mode);
110 	return (s && path == buf) ? strdup(s) : s;
111 }
112