1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1988 AT&T */
23 /* All Rights Reserved */
24
25
26 /*
27 * Copyright (c) 1999 by Sun Microsystems, Inc.
28 * All rights reserved.
29 */
30
31 /*
32 * compath(pathname)
33 *
34 * This compresses pathnames. All strings of multiple slashes are
35 * changed to a single slash. All occurrences of "./" are removed.
36 * Whenever possible, strings of "/.." are removed together with
37 * the directory names that they follow.
38 *
39 * WARNING: since pathname is altered by this function, it should
40 * be located in a temporary buffer. This avoids the problem
41 * of accidently changing strings obtained from makefiles
42 * and stored in global structures.
43 */
44
45 #include <string.h>
46
47 char *
compath(char * pathname)48 compath(char *pathname)
49 {
50 char *nextchar;
51 char *lastchar;
52 char *sofar;
53 char *pnend;
54
55 int pnlen;
56
57 /*
58 * do not change the path if it has no "/"
59 */
60
61 if (strchr(pathname, '/') == 0)
62 return (pathname);
63
64 /*
65 * find all strings consisting of more than one '/'
66 */
67
68 for (lastchar = pathname + 1; *lastchar != '\0'; lastchar++)
69 if ((*lastchar == '/') && (*(lastchar - 1) == '/')) {
70
71 /*
72 * find the character after the last slash
73 */
74
75 nextchar = lastchar;
76 while (*++lastchar == '/') {
77 }
78
79 /*
80 * eliminate the extra slashes by copying
81 * everything after the slashes over the slashes
82 */
83
84 sofar = nextchar;
85 while ((*nextchar++ = *lastchar++) != '\0')
86 ;
87 lastchar = sofar;
88 }
89
90 /*
91 * find all strings of "./"
92 */
93
94 for (lastchar = pathname + 1; *lastchar != '\0'; lastchar++)
95 if ((*lastchar == '/') && (*(lastchar - 1) == '.') &&
96 ((lastchar - 1 == pathname) || (*(lastchar - 2) == '/'))) {
97
98 /*
99 * copy everything after the "./" over the "./"
100 */
101
102 nextchar = lastchar - 1;
103 sofar = nextchar;
104 while ((*nextchar++ = *++lastchar) != '\0')
105 ;
106 lastchar = sofar;
107 }
108
109 /*
110 * find each occurrence of "/.."
111 */
112
113 for (lastchar = pathname + 1; *lastchar != '\0'; lastchar++)
114 if ((lastchar != pathname) && (*lastchar == '/') &&
115 (*(lastchar + 1) == '.') && (*(lastchar + 2) == '.') &&
116 ((*(lastchar + 3) == '/') || (*(lastchar + 3) == '\0'))) {
117
118 /*
119 * find the directory name preceding the "/.."
120 */
121
122 nextchar = lastchar - 1;
123 while ((nextchar != pathname) &&
124 (*(nextchar - 1) != '/'))
125 --nextchar;
126
127 /*
128 * make sure the preceding directory's name
129 * is not "." or ".."
130 */
131
132 if ((*nextchar == '.') &&
133 (*(nextchar + 1) == '/') ||
134 ((*(nextchar + 1) == '.') &&
135 (*(nextchar + 2) == '/'))) {
136 /* EMPTY */;
137 } else {
138
139 /*
140 * prepare to eliminate either
141 * "dir_name/../" or "dir_name/.."
142 */
143
144 if (*(lastchar + 3) == '/')
145 lastchar += 4;
146 else
147 lastchar += 3;
148
149 /*
150 * copy everything after the "/.." to
151 * before the preceding directory name
152 */
153
154 sofar = nextchar - 1;
155 while ((*nextchar++ = *lastchar++) != '\0');
156
157 lastchar = sofar;
158
159 /*
160 * if the character before what was taken
161 * out is '/', set up to check if the
162 * slash is part of "/.."
163 */
164
165 if ((sofar + 1 != pathname) && (*sofar == '/'))
166 --lastchar;
167 }
168 }
169
170 /*
171 * if the string is more than a character long and ends
172 * in '/', eliminate the '/'.
173 */
174
175 pnlen = strlen(pathname);
176 pnend = strchr(pathname, '\0') - 1;
177
178 if ((pnlen > 1) && (*pnend == '/')) {
179 *pnend-- = '\0';
180 pnlen--;
181 }
182
183 /*
184 * if the string has more than two characters and ends in
185 * "/.", remove the "/.".
186 */
187
188 if ((pnlen > 2) && (*(pnend - 1) == '/') && (*pnend == '.'))
189 *--pnend = '\0';
190
191 /*
192 * if all characters were deleted, return ".";
193 * otherwise return pathname
194 */
195
196 if (*pathname == '\0')
197 (void) strcpy(pathname, ".");
198
199 return (pathname);
200 }
201