-/* Copyright (C) 1991-1999, 2004-2009 Free Software Foundation, Inc.
+/* Copyright (C) 1991-1999, 2004-2014 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
#include <fcntl.h> /* For AT_FDCWD on Solaris 9. */
-/* If this host provides the openat function, then enable
+/* If this host provides the openat function or if we're using the
+ gnulib replacement function with a native fdopendir, then enable
code below to make getcwd more efficient and robust. */
-#ifdef HAVE_OPENAT
+#if defined HAVE_OPENAT || (defined GNULIB_OPENAT && defined HAVE_FDOPENDIR)
# define HAVE_OPENAT_SUPPORT 1
#else
# define HAVE_OPENAT_SUPPORT 0
# endif
#endif
-#include <limits.h>
-
#ifndef MAX
# define MAX(a, b) ((a) < (b) ? (b) : (a))
#endif
# define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif
+#include "pathmax.h"
+
+/* In this file, PATH_MAX only serves as a threshold for choosing among two
+ algorithms. */
#ifndef PATH_MAX
-# ifdef MAXPATHLEN
-# define PATH_MAX MAXPATHLEN
-# else
-# define PATH_MAX 1024
-# endif
+# define PATH_MAX 8192
#endif
#if D_INO_IN_DIRENT
/* 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,
+ 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 *
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.
+#if HAVE_MINIMALLY_WORKING_GETCWD
+ /* 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. */
+ openat-based approach does not.
+
+ But on AIX 5.1..7.1, the system getcwd is not even minimally
+ working: If the current directory name is slightly longer than
+ PATH_MAX, it omits the first directory component and returns
+ this wrong result with errno = 0. */
# undef getcwd
dir = getcwd (buf, size);
- if (dir || (errno != ERANGE && errno != ENAMETOOLONG && errno != ENOENT))
+ if (dir || (size && errno == ERANGE))
return dir;
+
+ /* Solaris getcwd (NULL, 0) fails with errno == EINVAL, but it has
+ internal magic that lets it work even if an ancestor directory is
+ inaccessible, which is better in many cases. So in this case try
+ again with a buffer that's almost always big enough. */
+ if (errno == EINVAL && buf == NULL && size == 0)
+ {
+ char big_buffer[BIG_FILE_NAME_LENGTH + 1];
+ dir = getcwd (big_buffer, sizeof big_buffer);
+ if (dir)
+ return strdup (dir);
+ }
+
+# 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 (errno != ERANGE && errno != ENAMETOOLONG && errno != ENOENT)
+ return NULL;
+# endif
#endif
if (size == 0)
{
if (buf != NULL)
- {
- __set_errno (EINVAL);
- return NULL;
- }
+ {
+ __set_errno (EINVAL);
+ return NULL;
+ }
allocated = BIG_FILE_NAME_LENGTH + 1;
}
{
dir = malloc (allocated);
if (dir == NULL)
- return NULL;
+ return NULL;
}
else
dir = buf;
#if HAVE_OPENAT_SUPPORT
fd = openat (fd, "..", O_RDONLY);
if (fd < 0)
- goto lose;
+ goto lose;
fd_needs_closing = true;
parent_status = fstat (fd, &st);
#else
parent_status = __lstat (dotlist, &st);
#endif
if (parent_status != 0)
- goto lose;
+ goto lose;
if (dirstream && __closedir (dirstream) != 0)
- {
- dirstream = NULL;
- goto lose;
- }
+ {
+ dirstream = NULL;
+ goto lose;
+ }
/* Figure out if this directory is a mount point. */
dotdev = st.st_dev;
#if HAVE_OPENAT_SUPPORT
dirstream = fdopendir (fd);
if (dirstream == NULL)
- goto lose;
- /* Reset fd. It may have been closed by fdopendir. */
- fd = dirfd (dirstream);
+ goto lose;
fd_needs_closing = false;
#else
dirstream = __opendir (dotlist);
if (dirstream == NULL)
- goto lose;
+ 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;
+ {
+ /* 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);
+ 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);
+ /* 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;
- }
- }
+ /* 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;
- }
- }
+ {
+ 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 = '/';
buf = realloc (dir, used);
if (buf == NULL)
- /* Either buf was NULL all along, or `realloc' failed but
+ /* Either buf was NULL all along, or 'realloc' failed but
we still have the original string. */
buf = dir;
projects / gnulib.git / blobdiff