1 /* pathcanon.c -- canonicalize and manipulate pathnames. */
3 /* Copyright (C) 2000 Free Software Foundation, Inc.
5 This file is part of GNU Bash, the Bourne Again SHell.
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.
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.
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/>.
23 #include <bashtypes.h>
25 # include <sys/param.h>
27 #include <posixstat.h>
29 #if defined (HAVE_UNISTD_H)
36 #include <chartypes.h>
45 #if defined (__CYGWIN__)
46 #include <sys/cygwin.h>
52 static char user[MAXPATHLEN];
53 static char system[MAXPATHLEN];
54 static int first_time = 1;
56 /* If the path is the first part of a network path, treat it as
58 if (path[0] == '/' && path[1] == '/' && !strchr (path + 2, '/'))
60 /* Otherwise check for /cygdrive prefix. */
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);
69 return !strcasecmp (path, user) || !strcasecmp (path, system);
71 #endif /* __CYGWIN__ */
73 /* Return 1 if PATH corresponds to a directory. A function for debugging. */
81 /* This should leave errno set to the correct value. */
83 l = stat (path, &sb) == 0 && S_ISDIR (sb.st_mode);
84 #if defined (__CYGWIN__)
86 l = _is_cygdrive (path);
91 /* Canonicalize PATH, and return a new path. The new path differs from PATH
93 Multple `/'s are collapsed to a single `/'.
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. */
99 /* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */
101 #define DOUBLE_SLASH(p) ((p[0] == '/') && (p[1] == '/') && p[2] != '/')
104 sh_canonpath (path, flags)
109 char *result, *p, *q, *base, *dotdot;
110 int rooted, double_slash_path;
112 /* The result cannot be larger than the input PATH. */
113 result = (flags & PATH_NOALLOC) ? path : savestring (path);
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))
120 #if defined (__CYGWIN__)
121 base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 3 : result + 1;
125 double_slash_path = DOUBLE_SLASH (path);
126 base += double_slash_path;
131 #if defined (__CYGWIN__)
132 base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 2 : result;
136 double_slash_path = 0;
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).
147 p = q = dotdot = base;
151 if (ISDIRSEP(p[0])) /* null element */
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 ../ */
157 p += 2; /* skip `..' */
158 if (q > dotdot) /* can backtrack */
160 if (flags & PATH_CHECKDOTDOT)
164 /* Make sure what we have so far corresponds to a valid
165 path before we chop some of it off. */
168 if (_path_isdir (result) == 0)
170 if ((flags & PATH_NOALLOC) == 0)
172 return ((char *)NULL);
177 while (--q > dotdot && ISDIRSEP(*q) == 0)
180 else if (rooted == 0)
182 /* /.. is / but ./../ is .. */
190 else /* real path element */
192 /* add separator if not at start of work portion of result */
195 while (*p && (ISDIRSEP(*p) == 0))
197 /* Check here for a valid directory with _path_isdir. */
198 if (flags & PATH_CHECKEXISTS)
202 /* Make sure what we have so far corresponds to a valid
203 path before we chop some of it off. */
206 if (_path_isdir (result) == 0)
208 if ((flags & PATH_NOALLOC) == 0)
210 return ((char *)NULL);
217 /* Empty string is really ``.'' or `/', depending on what we started with. */
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)
227 if (result[2] == '\0') /* short-circuit for bare `//' */
230 strcpy (result, result + 1);