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/* pathcanon.c -- canonicalize and manipulate pathnames. */
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/* Copyright (C) 2000 Free Software Foundation, Inc.
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This file is part of GNU Bash, the Bourne Again SHell.
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Bash is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Bash is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Bash. If not, see <http://www.gnu.org/licenses/>.
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#include <bashtypes.h>
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#if defined (HAVE_SYS_PARAM_H)
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# include <sys/param.h>
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#include <posixstat.h>
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#if defined (HAVE_UNISTD_H)
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#include <chartypes.h>
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#if defined (__CYGWIN__)
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#include <sys/cygwin.h>
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static char user[MAXPATHLEN];
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static char system[MAXPATHLEN];
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static int first_time = 1;
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/* If the path is the first part of a network path, treat it as
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if (path[0] == '/' && path[1] == '/' && !strchr (path + 2, '/'))
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/* Otherwise check for /cygdrive prefix. */
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char user_flags[MAXPATHLEN];
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char system_flags[MAXPATHLEN];
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/* Get the cygdrive info */
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cygwin_internal (CW_GET_CYGDRIVE_INFO, user, system, user_flags, system_flags);
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return !strcasecmp (path, user) || !strcasecmp (path, system);
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#endif /* __CYGWIN__ */
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/* Return 1 if PATH corresponds to a directory. A function for debugging. */
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/* This should leave errno set to the correct value. */
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l = stat (path, &sb) == 0 && S_ISDIR (sb.st_mode);
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#if defined (__CYGWIN__)
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l = _is_cygdrive (path);
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/* Canonicalize PATH, and return a new path. The new path differs from PATH
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Multple `/'s are collapsed to a single `/'.
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Leading `./'s and trailing `/.'s are removed.
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Trailing `/'s are removed.
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Non-leading `../'s and trailing `..'s are handled by removing
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portions of the path. */
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/* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */
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#define DOUBLE_SLASH(p) ((p[0] == '/') && (p[1] == '/') && p[2] != '/')
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sh_canonpath (path, flags)
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char *result, *p, *q, *base, *dotdot;
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int rooted, double_slash_path;
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/* The result cannot be larger than the input PATH. */
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result = (flags & PATH_NOALLOC) ? path : savestring (path);
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/* POSIX.2 says to leave a leading `//' alone. On cygwin, we skip over any
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leading `x:' (dos drive name). */
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if (rooted = ROOTEDPATH(path))
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#if defined (__CYGWIN__)
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base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 3 : result + 1;
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double_slash_path = DOUBLE_SLASH (path);
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base += double_slash_path;
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#if defined (__CYGWIN__)
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base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 2 : result;
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double_slash_path = 0;
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* base points to the portion of the path we want to modify
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* p points at beginning of path element we're considering.
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* q points just past the last path element we wrote (no slash).
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* dotdot points just past the point where .. cannot backtrack
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* any further (no slash).
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p = q = dotdot = base;
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if (ISDIRSEP(p[0])) /* null element */
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else if(p[0] == '.' && PATHSEP(p[1])) /* . and ./ */
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p += 1; /* don't count the separator in case it is nul */
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else if (p[0] == '.' && p[1] == '.' && PATHSEP(p[2])) /* .. and ../ */
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p += 2; /* skip `..' */
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if (q > dotdot) /* can backtrack */
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if (flags & PATH_CHECKDOTDOT)
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/* Make sure what we have so far corresponds to a valid
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path before we chop some of it off. */
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if (_path_isdir (result) == 0)
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if ((flags & PATH_NOALLOC) == 0)
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return ((char *)NULL);
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while (--q > dotdot && ISDIRSEP(*q) == 0)
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else if (rooted == 0)
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/* /.. is / but ./../ is .. */
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else /* real path element */
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/* add separator if not at start of work portion of result */
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while (*p && (ISDIRSEP(*p) == 0))
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/* Check here for a valid directory with _path_isdir. */
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if (flags & PATH_CHECKEXISTS)
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/* Make sure what we have so far corresponds to a valid
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path before we chop some of it off. */
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if (_path_isdir (result) == 0)
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if ((flags & PATH_NOALLOC) == 0)
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return ((char *)NULL);
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/* Empty string is really ``.'' or `/', depending on what we started with. */
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/* If the result starts with `//', but the original path does not, we
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can turn the // into /. Because of how we set `base', this should never
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be true, but it's a sanity check. */
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if (DOUBLE_SLASH(result) && double_slash_path == 0)
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if (result[2] == '\0') /* short-circuit for bare `//' */
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strcpy (result, result + 1);