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3185942a | 1 | /* pathcanon.c -- canonicalize and manipulate pathnames. */ |
28ef6c31 JA |
2 | |
3 | /* Copyright (C) 2000 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GNU Bash, the Bourne Again SHell. | |
6 | ||
3185942a JA |
7 | Bash is free software: you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation, either version 3 of the License, or | |
10 | (at your option) any later version. | |
28ef6c31 | 11 | |
3185942a JA |
12 | Bash is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
28ef6c31 | 16 | |
3185942a JA |
17 | You should have received a copy of the GNU General Public License |
18 | along with Bash. If not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
28ef6c31 | 20 | |
f73dda09 | 21 | #include <config.h> |
28ef6c31 | 22 | |
f73dda09 | 23 | #include <bashtypes.h> |
ac50fbac | 24 | #if defined (HAVE_SYS_PARAM_H) |
28ef6c31 JA |
25 | # include <sys/param.h> |
26 | #endif | |
f73dda09 | 27 | #include <posixstat.h> |
28ef6c31 JA |
28 | |
29 | #if defined (HAVE_UNISTD_H) | |
30 | # include <unistd.h> | |
31 | #endif | |
32 | ||
f73dda09 JA |
33 | #include <filecntl.h> |
34 | #include <bashansi.h> | |
28ef6c31 | 35 | #include <stdio.h> |
f73dda09 | 36 | #include <chartypes.h> |
b80f6443 | 37 | #include <errno.h> |
28ef6c31 JA |
38 | |
39 | #include "shell.h" | |
40 | ||
b80f6443 JA |
41 | #if !defined (errno) |
42 | extern int errno; | |
43 | #endif | |
44 | ||
7117c2d2 JA |
45 | #if defined (__CYGWIN__) |
46 | #include <sys/cygwin.h> | |
47 | ||
48 | static int | |
49 | _is_cygdrive (path) | |
50 | char *path; | |
51 | { | |
52 | static char user[MAXPATHLEN]; | |
53 | static char system[MAXPATHLEN]; | |
54 | static int first_time = 1; | |
55 | ||
56 | /* If the path is the first part of a network path, treat it as | |
57 | existing. */ | |
58 | if (path[0] == '/' && path[1] == '/' && !strchr (path + 2, '/')) | |
59 | return 1; | |
60 | /* Otherwise check for /cygdrive prefix. */ | |
61 | if (first_time) | |
62 | { | |
63 | char user_flags[MAXPATHLEN]; | |
64 | char system_flags[MAXPATHLEN]; | |
65 | /* Get the cygdrive info */ | |
66 | cygwin_internal (CW_GET_CYGDRIVE_INFO, user, system, user_flags, system_flags); | |
67 | first_time = 0; | |
68 | } | |
69 | return !strcasecmp (path, user) || !strcasecmp (path, system); | |
70 | } | |
71 | #endif /* __CYGWIN__ */ | |
72 | ||
28ef6c31 JA |
73 | /* Return 1 if PATH corresponds to a directory. A function for debugging. */ |
74 | static int | |
75 | _path_isdir (path) | |
76 | char *path; | |
77 | { | |
95732b49 | 78 | int l; |
28ef6c31 JA |
79 | struct stat sb; |
80 | ||
b80f6443 | 81 | /* This should leave errno set to the correct value. */ |
95732b49 | 82 | errno = 0; |
28ef6c31 | 83 | l = stat (path, &sb) == 0 && S_ISDIR (sb.st_mode); |
7117c2d2 JA |
84 | #if defined (__CYGWIN__) |
85 | if (l == 0) | |
86 | l = _is_cygdrive (path); | |
87 | #endif | |
28ef6c31 JA |
88 | return l; |
89 | } | |
90 | ||
91 | /* Canonicalize PATH, and return a new path. The new path differs from PATH | |
92 | in that: | |
8868edaf | 93 | Multiple `/'s are collapsed to a single `/'. |
28ef6c31 JA |
94 | Leading `./'s and trailing `/.'s are removed. |
95 | Trailing `/'s are removed. | |
96 | Non-leading `../'s and trailing `..'s are handled by removing | |
97 | portions of the path. */ | |
98 | ||
99 | /* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */ | |
100 | ||
101 | #define DOUBLE_SLASH(p) ((p[0] == '/') && (p[1] == '/') && p[2] != '/') | |
102 | ||
103 | char * | |
104 | sh_canonpath (path, flags) | |
105 | char *path; | |
106 | int flags; | |
107 | { | |
108 | char stub_char; | |
109 | char *result, *p, *q, *base, *dotdot; | |
110 | int rooted, double_slash_path; | |
111 | ||
112 | /* The result cannot be larger than the input PATH. */ | |
113 | result = (flags & PATH_NOALLOC) ? path : savestring (path); | |
114 | ||
115 | /* POSIX.2 says to leave a leading `//' alone. On cygwin, we skip over any | |
116 | leading `x:' (dos drive name). */ | |
117 | if (rooted = ROOTEDPATH(path)) | |
118 | { | |
119 | stub_char = DIRSEP; | |
120 | #if defined (__CYGWIN__) | |
f73dda09 | 121 | base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 3 : result + 1; |
28ef6c31 JA |
122 | #else |
123 | base = result + 1; | |
124 | #endif | |
125 | double_slash_path = DOUBLE_SLASH (path); | |
126 | base += double_slash_path; | |
127 | } | |
128 | else | |
129 | { | |
130 | stub_char = '.'; | |
131 | #if defined (__CYGWIN__) | |
f73dda09 | 132 | base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 2 : result; |
28ef6c31 JA |
133 | #else |
134 | base = result; | |
135 | #endif | |
f73dda09 | 136 | double_slash_path = 0; |
28ef6c31 JA |
137 | } |
138 | ||
139 | /* | |
140 | * invariants: | |
141 | * base points to the portion of the path we want to modify | |
142 | * p points at beginning of path element we're considering. | |
143 | * q points just past the last path element we wrote (no slash). | |
144 | * dotdot points just past the point where .. cannot backtrack | |
145 | * any further (no slash). | |
146 | */ | |
147 | p = q = dotdot = base; | |
148 | ||
149 | while (*p) | |
150 | { | |
151 | if (ISDIRSEP(p[0])) /* null element */ | |
152 | p++; | |
153 | else if(p[0] == '.' && PATHSEP(p[1])) /* . and ./ */ | |
154 | p += 1; /* don't count the separator in case it is nul */ | |
155 | else if (p[0] == '.' && p[1] == '.' && PATHSEP(p[2])) /* .. and ../ */ | |
156 | { | |
157 | p += 2; /* skip `..' */ | |
158 | if (q > dotdot) /* can backtrack */ | |
159 | { | |
160 | if (flags & PATH_CHECKDOTDOT) | |
161 | { | |
162 | char c; | |
163 | ||
164 | /* Make sure what we have so far corresponds to a valid | |
165 | path before we chop some of it off. */ | |
166 | c = *q; | |
167 | *q = '\0'; | |
168 | if (_path_isdir (result) == 0) | |
169 | { | |
170 | if ((flags & PATH_NOALLOC) == 0) | |
171 | free (result); | |
172 | return ((char *)NULL); | |
173 | } | |
174 | *q = c; | |
175 | } | |
176 | ||
177 | while (--q > dotdot && ISDIRSEP(*q) == 0) | |
178 | ; | |
179 | } | |
180 | else if (rooted == 0) | |
181 | { | |
182 | /* /.. is / but ./../ is .. */ | |
183 | if (q != base) | |
184 | *q++ = DIRSEP; | |
185 | *q++ = '.'; | |
186 | *q++ = '.'; | |
187 | dotdot = q; | |
188 | } | |
189 | } | |
190 | else /* real path element */ | |
191 | { | |
192 | /* add separator if not at start of work portion of result */ | |
193 | if (q != base) | |
194 | *q++ = DIRSEP; | |
195 | while (*p && (ISDIRSEP(*p) == 0)) | |
196 | *q++ = *p++; | |
197 | /* Check here for a valid directory with _path_isdir. */ | |
198 | if (flags & PATH_CHECKEXISTS) | |
199 | { | |
200 | char c; | |
201 | ||
202 | /* Make sure what we have so far corresponds to a valid | |
203 | path before we chop some of it off. */ | |
204 | c = *q; | |
205 | *q = '\0'; | |
206 | if (_path_isdir (result) == 0) | |
207 | { | |
208 | if ((flags & PATH_NOALLOC) == 0) | |
209 | free (result); | |
210 | return ((char *)NULL); | |
211 | } | |
212 | *q = c; | |
213 | } | |
214 | } | |
215 | } | |
216 | ||
217 | /* Empty string is really ``.'' or `/', depending on what we started with. */ | |
218 | if (q == result) | |
219 | *q++ = stub_char; | |
220 | *q = '\0'; | |
221 | ||
222 | /* If the result starts with `//', but the original path does not, we | |
223 | can turn the // into /. Because of how we set `base', this should never | |
224 | be true, but it's a sanity check. */ | |
225 | if (DOUBLE_SLASH(result) && double_slash_path == 0) | |
226 | { | |
227 | if (result[2] == '\0') /* short-circuit for bare `//' */ | |
228 | result[1] = '\0'; | |
229 | else | |
d233b485 | 230 | memmove (result, result + 1, strlen (result + 1) + 1); |
28ef6c31 JA |
231 | } |
232 | ||
233 | return (result); | |
234 | } |