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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:38:56 +0000 |
commit | 6c20c8ed2cb9ab69a1a57ccb2b9b79969a808321 (patch) | |
tree | f63ce19d57fad3ac4a15bc26dbfbfa2b834111b5 /lib/sh/pathphys.c | |
parent | Initial commit. (diff) | |
download | bash-upstream/5.2.15.tar.xz bash-upstream/5.2.15.zip |
Adding upstream version 5.2.15.upstream/5.2.15upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/sh/pathphys.c')
-rw-r--r-- | lib/sh/pathphys.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/lib/sh/pathphys.c b/lib/sh/pathphys.c new file mode 100644 index 0000000..95b72f1 --- /dev/null +++ b/lib/sh/pathphys.c @@ -0,0 +1,296 @@ +/* pathphys.c -- return pathname with all symlinks expanded. */ + +/* Copyright (C) 2000-2020 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 (MAXSYMLINKS) +# define MAXSYMLINKS 32 +#endif + +#if !defined (errno) +extern int errno; +#endif /* !errno */ + +extern char *get_working_directory PARAMS((char *)); + +static int +_path_readlink (path, buf, bufsiz) + char *path; + char *buf; + int bufsiz; +{ +#ifdef HAVE_READLINK + return readlink (path, buf, bufsiz); +#else + errno = EINVAL; + return -1; +#endif +} + +/* Look for ROOTEDPATH, PATHSEP, DIRSEP, and ISDIRSEP in ../../general.h */ + +#define DOUBLE_SLASH(p) ((p[0] == '/') && (p[1] == '/') && p[2] != '/') + +/* + * Return PATH with all symlinks expanded in newly-allocated memory. + * This always gets an absolute pathname. + */ + +char * +sh_physpath (path, flags) + char *path; + int flags; +{ + char tbuf[PATH_MAX+1], linkbuf[PATH_MAX+1]; + char *result, *p, *q, *qsave, *qbase, *workpath; + int double_slash_path, linklen, nlink; + + linklen = strlen (path); + +#if 0 + /* First sanity check -- punt immediately if the name is too long. */ + if (linklen >= PATH_MAX) + return (savestring (path)); +#endif + + nlink = 0; + q = result = (char *)xmalloc (PATH_MAX + 1); + + /* Even if we get something longer than PATH_MAX, we might be able to + shorten it, so we try. */ + if (linklen >= PATH_MAX) + workpath = savestring (path); + else + { + workpath = (char *)xmalloc (PATH_MAX + 1); + strcpy (workpath, path); + } + + /* This always gets an absolute pathname. */ + + /* POSIX.2 says to leave a leading `//' alone. On cygwin, we skip over any + leading `x:' (dos drive name). */ +#if defined (__CYGWIN__) + qbase = (ISALPHA((unsigned char)workpath[0]) && workpath[1] == ':') ? workpath + 3 : workpath + 1; +#else + qbase = workpath + 1; +#endif + double_slash_path = DOUBLE_SLASH (workpath); + qbase += double_slash_path; + + for (p = workpath; p < qbase; ) + *q++ = *p++; + qbase = q; + + /* + * invariants: + * qbase points to the portion of the result 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). + * + * XXX -- need to fix error checking for too-long pathnames + */ + + 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 > qbase) + { + while (--q > qbase && ISDIRSEP(*q) == 0) + ; + } + } + else /* real path element */ + { + /* add separator if not at start of work portion of result */ + qsave = q; + if (q != qbase) + *q++ = DIRSEP; + while (*p && (ISDIRSEP(*p) == 0)) + { + if (q - result >= PATH_MAX) + { +#ifdef ENAMETOOLONG + errno = ENAMETOOLONG; +#else + errno = EINVAL; +#endif + goto error; + } + + *q++ = *p++; + } + + *q = '\0'; + + linklen = _path_readlink (result, linkbuf, PATH_MAX); + if (linklen < 0) /* if errno == EINVAL, it's not a symlink */ + { + if (errno != EINVAL) + goto error; + continue; + } + + /* It's a symlink, and the value is in LINKBUF. */ + nlink++; + if (nlink > MAXSYMLINKS) + { +#ifdef ELOOP + errno = ELOOP; +#else + errno = EINVAL; +#endif +error: + free (result); + free (workpath); + return ((char *)NULL); + } + + linkbuf[linklen] = '\0'; + + /* If the new path length would overrun PATH_MAX, punt now. */ + if ((strlen (p) + linklen + 2) >= PATH_MAX) + { +#ifdef ENAMETOOLONG + errno = ENAMETOOLONG; +#else + errno = EINVAL; +#endif + goto error; + } + + /* Form the new pathname by copying the link value to a temporary + buffer and appending the rest of `workpath'. Reset p to point + to the start of the rest of the path. If the link value is an + absolute pathname, reset p, q, and qbase. If not, reset p + and q. */ + strcpy (tbuf, linkbuf); + tbuf[linklen] = '/'; + strcpy (tbuf + linklen, p); + strcpy (workpath, tbuf); + + if (ABSPATH(linkbuf)) + { + q = result; + /* Duplicating some code here... */ +#if defined (__CYGWIN__) + qbase = (ISALPHA((unsigned char)workpath[0]) && workpath[1] == ':') ? workpath + 3 : workpath + 1; +#else + qbase = workpath + 1; +#endif + double_slash_path = DOUBLE_SLASH (workpath); + qbase += double_slash_path; + + for (p = workpath; p < qbase; ) + *q++ = *p++; + qbase = q; + } + else + { + p = workpath; + q = qsave; + } + } + } + + *q = '\0'; + free (workpath); + + /* If the result starts with `//', but the original path does not, we + can turn the // into /. Because of how we set `qbase', 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); +} + +char * +sh_realpath (pathname, resolved) + const char *pathname; + char *resolved; +{ + char *tdir, *wd; + + if (pathname == 0 || *pathname == '\0') + { + errno = (pathname == 0) ? EINVAL : ENOENT; + return ((char *)NULL); + } + + if (ABSPATH (pathname) == 0) + { + wd = get_working_directory ("sh_realpath"); + if (wd == 0) + return ((char *)NULL); + tdir = sh_makepath (wd, (char *)pathname, 0); + free (wd); + } + else + tdir = savestring (pathname); + + wd = sh_physpath (tdir, 0); + free (tdir); + + if (resolved == 0) + return (wd); + + if (wd) + { + strncpy (resolved, wd, PATH_MAX - 1); + resolved[PATH_MAX - 1] = '\0'; + free (wd); + return resolved; + } + else + { + resolved[0] = '\0'; + return wd; + } +} |