+++ /dev/null
-/* Copyright (C) 1991-1999, 2004-2008 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- This program 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.
-
- This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
-
-#if !_LIBC
-# include <config.h>
-# include <unistd.h>
-#endif
-
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <stdbool.h>
-#include <stddef.h>
-
-#include <fcntl.h> /* For AT_FDCWD on Solaris 9. */
-
-/* If this host provides the openat function, then enable
- code below to make getcwd more efficient and robust. */
-#ifdef HAVE_OPENAT
-# define HAVE_OPENAT_SUPPORT 1
-#else
-# define HAVE_OPENAT_SUPPORT 0
-#endif
-
-#ifndef __set_errno
-# define __set_errno(val) (errno = (val))
-#endif
-
-#include <dirent.h>
-#ifndef _D_EXACT_NAMLEN
-# define _D_EXACT_NAMLEN(d) strlen ((d)->d_name)
-#endif
-#ifndef _D_ALLOC_NAMLEN
-# define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
-#endif
-
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-
-#if _LIBC
-# ifndef mempcpy
-# define mempcpy __mempcpy
-# endif
-#endif
-
-#include <limits.h>
-
-/* Work around a bug in Solaris 9 and 10: AT_FDCWD is positive. Its
- value exceeds INT_MAX, so its use as an int doesn't conform to the
- C standard, and GCC and Sun C complain in some cases. */
-#if 0 < AT_FDCWD && AT_FDCWD == 0xffd19553
-# undef AT_FDCWD
-# define AT_FDCWD (-3041965)
-#endif
-
-#ifdef ENAMETOOLONG
-# define is_ENAMETOOLONG(x) ((x) == ENAMETOOLONG)
-#else
-# define is_ENAMETOOLONG(x) 0
-#endif
-
-#ifndef MAX
-# define MAX(a, b) ((a) < (b) ? (b) : (a))
-#endif
-#ifndef MIN
-# define MIN(a, b) ((a) < (b) ? (a) : (b))
-#endif
-
-#ifndef PATH_MAX
-# ifdef MAXPATHLEN
-# define PATH_MAX MAXPATHLEN
-# else
-# define PATH_MAX 1024
-# endif
-#endif
-
-#if D_INO_IN_DIRENT
-# define MATCHING_INO(dp, ino) ((dp)->d_ino == (ino))
-#else
-# define MATCHING_INO(dp, ino) true
-#endif
-
-#if !_LIBC
-# define __getcwd rpl_getcwd
-# define __lstat lstat
-# define __closedir closedir
-# define __opendir opendir
-# define __readdir readdir
-#endif
-
-/* The results of opendir() in this file are not used with dirfd and fchdir,
- therefore save some unnecessary recursion in fchdir.c. */
-#undef opendir
-#undef closedir
-\f
-/* Get the name of the current working directory, and put it in SIZE
- bytes of BUF. Returns NULL if the directory couldn't be determined or
- SIZE was too small. If successful, returns BUF. In GNU, if BUF is
- NULL, an array is allocated with `malloc'; the array is SIZE bytes long,
- unless SIZE == 0, in which case it is as big as necessary. */
-
-char *
-__getcwd (char *buf, size_t size)
-{
- /* Lengths of big file name components and entire file names, and a
- deep level of file name nesting. These numbers are not upper
- bounds; they are merely large values suitable for initial
- allocations, designed to be large enough for most real-world
- uses. */
- enum
- {
- BIG_FILE_NAME_COMPONENT_LENGTH = 255,
- BIG_FILE_NAME_LENGTH = MIN (4095, PATH_MAX - 1),
- DEEP_NESTING = 100
- };
-
-#if HAVE_OPENAT_SUPPORT
- int fd = AT_FDCWD;
- bool fd_needs_closing = false;
-#else
- char dots[DEEP_NESTING * sizeof ".." + BIG_FILE_NAME_COMPONENT_LENGTH + 1];
- char *dotlist = dots;
- size_t dotsize = sizeof dots;
- size_t dotlen = 0;
-#endif
- DIR *dirstream = NULL;
- dev_t rootdev, thisdev;
- ino_t rootino, thisino;
- char *dir;
- register char *dirp;
- struct stat st;
- size_t allocated = size;
- size_t used;
-
-#if HAVE_PARTLY_WORKING_GETCWD
- /* The system getcwd works, except it sometimes fails when it
- shouldn't, setting errno to ERANGE, ENAMETOOLONG, or ENOENT. If
- AT_FDCWD is not defined, the algorithm below is O(N**2) and this
- is much slower than the system getcwd (at least on GNU/Linux).
- So trust the system getcwd's results unless they look
- suspicious.
-
- Use the system getcwd even if we have openat support, since the
- system getcwd works even when a parent is unreadable, while the
- openat-based approach does not. */
-
-# undef getcwd
- dir = getcwd (buf, size);
- if (dir || (errno != ERANGE && !is_ENAMETOOLONG (errno) && errno != ENOENT))
- return dir;
-#endif
-
- if (size == 0)
- {
- if (buf != NULL)
- {
- __set_errno (EINVAL);
- return NULL;
- }
-
- allocated = BIG_FILE_NAME_LENGTH + 1;
- }
-
- if (buf == NULL)
- {
- dir = malloc (allocated);
- if (dir == NULL)
- return NULL;
- }
- else
- dir = buf;
-
- dirp = dir + allocated;
- *--dirp = '\0';
-
- if (__lstat (".", &st) < 0)
- goto lose;
- thisdev = st.st_dev;
- thisino = st.st_ino;
-
- if (__lstat ("/", &st) < 0)
- goto lose;
- rootdev = st.st_dev;
- rootino = st.st_ino;
-
- while (!(thisdev == rootdev && thisino == rootino))
- {
- struct dirent *d;
- dev_t dotdev;
- ino_t dotino;
- bool mount_point;
- int parent_status;
- size_t dirroom;
- size_t namlen;
- bool use_d_ino = true;
-
- /* Look at the parent directory. */
-#if HAVE_OPENAT_SUPPORT
- fd = openat (fd, "..", O_RDONLY);
- if (fd < 0)
- goto lose;
- fd_needs_closing = true;
- parent_status = fstat (fd, &st);
-#else
- dotlist[dotlen++] = '.';
- dotlist[dotlen++] = '.';
- dotlist[dotlen] = '\0';
- parent_status = __lstat (dotlist, &st);
-#endif
- if (parent_status != 0)
- goto lose;
-
- if (dirstream && __closedir (dirstream) != 0)
- {
- dirstream = NULL;
- goto lose;
- }
-
- /* Figure out if this directory is a mount point. */
- dotdev = st.st_dev;
- dotino = st.st_ino;
- mount_point = dotdev != thisdev;
-
- /* Search for the last directory. */
-#if HAVE_OPENAT_SUPPORT
- dirstream = fdopendir (fd);
- if (dirstream == NULL)
- goto lose;
- /* Reset fd. It may have been closed by fdopendir. */
- fd = dirfd (dirstream);
- fd_needs_closing = false;
-#else
- dirstream = __opendir (dotlist);
- if (dirstream == NULL)
- goto lose;
- dotlist[dotlen++] = '/';
-#endif
- for (;;)
- {
- /* Clear errno to distinguish EOF from error if readdir returns
- NULL. */
- __set_errno (0);
- d = __readdir (dirstream);
-
- /* When we've iterated through all directory entries without finding
- one with a matching d_ino, rewind the stream and consider each
- name again, but this time, using lstat. This is necessary in a
- chroot on at least one system (glibc-2.3.6 + linux 2.6.12), where
- .., ../.., ../../.., etc. all had the same device number, yet the
- d_ino values for entries in / did not match those obtained
- via lstat. */
- if (d == NULL && errno == 0 && use_d_ino)
- {
- use_d_ino = false;
- rewinddir (dirstream);
- d = __readdir (dirstream);
- }
-
- if (d == NULL)
- {
- if (errno == 0)
- /* EOF on dirstream, which can mean e.g., that the current
- directory has been removed. */
- __set_errno (ENOENT);
- goto lose;
- }
- if (d->d_name[0] == '.' &&
- (d->d_name[1] == '\0' ||
- (d->d_name[1] == '.' && d->d_name[2] == '\0')))
- continue;
-
- if (use_d_ino)
- {
- bool match = (MATCHING_INO (d, thisino) || mount_point);
- if (! match)
- continue;
- }
-
- {
- int entry_status;
-#if HAVE_OPENAT_SUPPORT
- entry_status = fstatat (fd, d->d_name, &st, AT_SYMLINK_NOFOLLOW);
-#else
- /* Compute size needed for this file name, or for the file
- name ".." in the same directory, whichever is larger.
- Room for ".." might be needed the next time through
- the outer loop. */
- size_t name_alloc = _D_ALLOC_NAMLEN (d);
- size_t filesize = dotlen + MAX (sizeof "..", name_alloc);
-
- if (filesize < dotlen)
- goto memory_exhausted;
-
- if (dotsize < filesize)
- {
- /* My, what a deep directory tree you have, Grandma. */
- size_t newsize = MAX (filesize, dotsize * 2);
- size_t i;
- if (newsize < dotsize)
- goto memory_exhausted;
- if (dotlist != dots)
- free (dotlist);
- dotlist = malloc (newsize);
- if (dotlist == NULL)
- goto lose;
- dotsize = newsize;
-
- i = 0;
- do
- {
- dotlist[i++] = '.';
- dotlist[i++] = '.';
- dotlist[i++] = '/';
- }
- while (i < dotlen);
- }
-
- memcpy (dotlist + dotlen, d->d_name, _D_ALLOC_NAMLEN (d));
- entry_status = __lstat (dotlist, &st);
-#endif
- /* We don't fail here if we cannot stat() a directory entry.
- This can happen when (network) file systems fail. If this
- entry is in fact the one we are looking for we will find
- out soon as we reach the end of the directory without
- having found anything. */
- if (entry_status == 0 && S_ISDIR (st.st_mode)
- && st.st_dev == thisdev && st.st_ino == thisino)
- break;
- }
- }
-
- dirroom = dirp - dir;
- namlen = _D_EXACT_NAMLEN (d);
-
- if (dirroom <= namlen)
- {
- if (size != 0)
- {
- __set_errno (ERANGE);
- goto lose;
- }
- else
- {
- char *tmp;
- size_t oldsize = allocated;
-
- allocated += MAX (allocated, namlen);
- if (allocated < oldsize
- || ! (tmp = realloc (dir, allocated)))
- goto memory_exhausted;
-
- /* Move current contents up to the end of the buffer.
- This is guaranteed to be non-overlapping. */
- dirp = memcpy (tmp + allocated - (oldsize - dirroom),
- tmp + dirroom,
- oldsize - dirroom);
- dir = tmp;
- }
- }
- dirp -= namlen;
- memcpy (dirp, d->d_name, namlen);
- *--dirp = '/';
-
- thisdev = dotdev;
- thisino = dotino;
- }
-
- if (dirstream && __closedir (dirstream) != 0)
- {
- dirstream = NULL;
- goto lose;
- }
-
- if (dirp == &dir[allocated - 1])
- *--dirp = '/';
-
-#if ! HAVE_OPENAT_SUPPORT
- if (dotlist != dots)
- free (dotlist);
-#endif
-
- used = dir + allocated - dirp;
- memmove (dir, dirp, used);
-
- if (size == 0)
- /* Ensure that the buffer is only as large as necessary. */
- buf = realloc (dir, used);
-
- if (buf == NULL)
- /* Either buf was NULL all along, or `realloc' failed but
- we still have the original string. */
- buf = dir;
-
- return buf;
-
- memory_exhausted:
- __set_errno (ENOMEM);
- lose:
- {
- int save = errno;
- if (dirstream)
- __closedir (dirstream);
-#if HAVE_OPENAT_SUPPORT
- if (fd_needs_closing)
- close (fd);
-#else
- if (dotlist != dots)
- free (dotlist);
-#endif
- if (buf == NULL)
- free (dir);
- __set_errno (save);
- }
- return NULL;
-}
-
-#ifdef weak_alias
-weak_alias (__getcwd, getcwd)
-#endif
projects / tar / blobdiff