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Diffstat (limited to 'lib/sh/pathcanon.c')
| -rw-r--r-- | lib/sh/pathcanon.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/lib/sh/pathcanon.c b/lib/sh/pathcanon.c new file mode 100644 index 0000000..7d0df9f --- /dev/null +++ b/lib/sh/pathcanon.c @@ -0,0 +1,234 @@ +/* pathcanon.c -- canonicalize and manipulate pathnames. */ + +/* Copyright (C) 2000 Free Software Foundation, Inc. + + This file is part of GNU Bash, the Bourne Again SHell. + + Bash is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Bash is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <config.h> + +#include <bashtypes.h> +#if defined (HAVE_SYS_PARAM_H) +# include <sys/param.h> +#endif +#include <posixstat.h> + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include <filecntl.h> +#include <bashansi.h> +#include <stdio.h> +#include <chartypes.h> +#include <errno.h> + +#include "shell.h" + +#if !defined (errno) +extern int errno; +#endif + +#if defined (__CYGWIN__) +#include <sys/cygwin.h> + +static int +_is_cygdrive (path) + char *path; +{ + static char user[MAXPATHLEN]; + static char system[MAXPATHLEN]; + static int first_time = 1; + + /* If the path is the first part of a network path, treat it as + existing. */ + if (path[0] == '/' && path[1] == '/' && !strchr (path + 2, '/')) + return 1; + /* Otherwise check for /cygdrive prefix. */ + if (first_time) + { + char user_flags[MAXPATHLEN]; + char system_flags[MAXPATHLEN]; + /* Get the cygdrive info */ + cygwin_internal (CW_GET_CYGDRIVE_INFO, user, system, user_flags, system_flags); + first_time = 0; + } + return !strcasecmp (path, user) || !strcasecmp (path, system); +} +#endif /* __CYGWIN__ */ + +/* Return 1 if PATH corresponds to a directory. A function for debugging. */ +static int +_path_isdir (path) + char *path; +{ + int l; + struct stat sb; + + /* This should leave errno set to the correct value. */ + errno = 0; + l = stat (path, &sb) == 0 && S_ISDIR (sb.st_mode); +#if defined (__CYGWIN__) + if (l == 0) + l = _is_cygdrive (path); +#endif + return l; +} + +/* Canonicalize PATH, and return a new path. The new path differs from PATH + in that: + Multiple `/'s are collapsed to a single `/'. + Leading `./'s and trailing `/.'s are removed. + Trailing `/'s are removed. + Non-leading `../'s and trailing `..'s are handled by removing + portions of the path. */ + +/* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */ + +#define DOUBLE_SLASH(p) ((p[0] == '/') && (p[1] == '/') && p[2] != '/') + +char * +sh_canonpath (path, flags) + char *path; + int flags; +{ + char stub_char; + char *result, *p, *q, *base, *dotdot; + int rooted, double_slash_path; + + /* The result cannot be larger than the input PATH. */ + result = (flags & PATH_NOALLOC) ? path : savestring (path); + + /* POSIX.2 says to leave a leading `//' alone. On cygwin, we skip over any + leading `x:' (dos drive name). */ + if (rooted = ROOTEDPATH(path)) + { + stub_char = DIRSEP; +#if defined (__CYGWIN__) + base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 3 : result + 1; +#else + base = result + 1; +#endif + double_slash_path = DOUBLE_SLASH (path); + base += double_slash_path; + } + else + { + stub_char = '.'; +#if defined (__CYGWIN__) + base = (ISALPHA((unsigned char)result[0]) && result[1] == ':') ? result + 2 : result; +#else + base = result; +#endif + double_slash_path = 0; + } + + /* + * invariants: + * base points to the portion of the path we want to modify + * p points at beginning of path element we're considering. + * q points just past the last path element we wrote (no slash). + * dotdot points just past the point where .. cannot backtrack + * any further (no slash). + */ + p = q = dotdot = base; + + while (*p) + { + if (ISDIRSEP(p[0])) /* null element */ + p++; + else if(p[0] == '.' && PATHSEP(p[1])) /* . and ./ */ + p += 1; /* don't count the separator in case it is nul */ + else if (p[0] == '.' && p[1] == '.' && PATHSEP(p[2])) /* .. and ../ */ + { + p += 2; /* skip `..' */ + if (q > dotdot) /* can backtrack */ + { + if (flags & PATH_CHECKDOTDOT) + { + char c; + + /* Make sure what we have so far corresponds to a valid + path before we chop some of it off. */ + c = *q; + *q = '\0'; + if (_path_isdir (result) == 0) + { + if ((flags & PATH_NOALLOC) == 0) + free (result); + return ((char *)NULL); + } + *q = c; + } + + while (--q > dotdot && ISDIRSEP(*q) == 0) + ; + } + else if (rooted == 0) + { + /* /.. is / but ./../ is .. */ + if (q != base) + *q++ = DIRSEP; + *q++ = '.'; + *q++ = '.'; + dotdot = q; + } + } + else /* real path element */ + { + /* add separator if not at start of work portion of result */ + if (q != base) + *q++ = DIRSEP; + while (*p && (ISDIRSEP(*p) == 0)) + *q++ = *p++; + /* Check here for a valid directory with _path_isdir. */ + if (flags & PATH_CHECKEXISTS) + { + char c; + + /* Make sure what we have so far corresponds to a valid + path before we chop some of it off. */ + c = *q; + *q = '\0'; + if (_path_isdir (result) == 0) + { + if ((flags & PATH_NOALLOC) == 0) + free (result); + return ((char *)NULL); + } + *q = c; + } + } + } + + /* Empty string is really ``.'' or `/', depending on what we started with. */ + if (q == result) + *q++ = stub_char; + *q = '\0'; + + /* If the result starts with `//', but the original path does not, we + can turn the // into /. Because of how we set `base', this should never + be true, but it's a sanity check. */ + if (DOUBLE_SLASH(result) && double_slash_path == 0) + { + if (result[2] == '\0') /* short-circuit for bare `//' */ + result[1] = '\0'; + else + memmove (result, result + 1, strlen (result + 1) + 1); + } + + return (result); +} |