char *
__realpath (const char *name, char *resolved)
{
char *rpath, *dest, *extra_buf = NULL;
const char *start, *end, *rpath_limit;
long int path_max;
int num_links = 0;
size_t prefix_len;
if (name == NULL)
{
/* As per Single Unix Specification V2 we must return an error if
either parameter is a null pointer. We extend this to allow
the RESOLVED parameter to be NULL in case the we are expected to
allocate the room for the return value. */
__set_errno (EINVAL);
return NULL;
}
if (name[0] == '\0')
{
/* As per Single Unix Specification V2 we must return an error if
the name argument points to an empty string. */
__set_errno (ENOENT);
return NULL;
}
#ifdef PATH_MAX
path_max = PATH_MAX;
#else
path_max = pathconf (name, _PC_PATH_MAX);
if (path_max <= 0)
path_max = 8192;
#endif
if (resolved == NULL)
{
rpath = malloc (path_max);
if (rpath == NULL)
{
/* It's easier to set errno to ENOMEM than to rely on the
'malloc-posix' gnulib module. */
errno = ENOMEM;
return NULL;
}
}
else
rpath = resolved;
rpath_limit = rpath + path_max;
/* This is always zero for Posix hosts, but can be 2 for MS-Windows
and MS-DOS X:/foo/bar file names. */
prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
if (!IS_ABSOLUTE_FILE_NAME (name))
{
if (!__getcwd (rpath, path_max))
{
rpath[0] = '\0';
goto error;
}
dest = strchr (rpath, '\0');
start = name;
prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath);
}
else
{
dest = rpath;
if (prefix_len)
{
memcpy (rpath, name, prefix_len);
dest += prefix_len;
}
*dest++ = '/';
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
*dest++ = '/';
*dest = '\0';
}
start = name + prefix_len;
}
for (end = start; *start; start = end)
{
#ifdef _LIBC
struct stat64 st;
#else
struct stat st;
#endif
int n;
/* Skip sequence of multiple path-separators. */
while (ISSLASH (*start))
++start;
/* Find end of path component. */
for (end = start; *end && !ISSLASH (*end); ++end)
/* Nothing. */;
if (end - start == 0)
break;
else if (end - start == 1 && start[0] == '.')
/* nothing */;
else if (end - start == 2 && start[0] == '.' && start[1] == '.')
{
/* Back up to previous component, ignore if at root already. */
if (dest > rpath + prefix_len + 1)
for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT
&& dest == rpath + 1 && !prefix_len
&& ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
}
else
{
size_t new_size;
if (!ISSLASH (dest[-1]))
*dest++ = '/';
if (dest + (end - start) >= rpath_limit)
{
ptrdiff_t dest_offset = dest - rpath;
char *new_rpath;
if (resolved)
{
__set_errno (ENAMETOOLONG);
if (dest > rpath + prefix_len + 1)
dest--;
*dest = '\0';
goto error;
}
new_size = rpath_limit - rpath;
if (end - start + 1 > path_max)
new_size += end - start + 1;
else
new_size += path_max;
new_rpath = (char *) realloc (rpath, new_size);
if (new_rpath == NULL)
{
/* It's easier to set errno to ENOMEM than to rely on the
'realloc-posix' gnulib module. */
errno = ENOMEM;
goto error;
}
rpath = new_rpath;
rpath_limit = rpath + new_size;
dest = rpath + dest_offset;
}
#ifdef _LIBC
dest = __mempcpy (dest, start, end - start);
#else
memcpy (dest, start, end - start);
dest += end - start;
#endif
*dest = '\0';
#ifdef _LIBC
if (__lxstat64 (_STAT_VER, rpath, &st) < 0)
#else
if (lstat (rpath, &st) < 0)
#endif
goto error;
if (S_ISLNK (st.st_mode))
{
char *buf;
size_t len;
if (++num_links > MAXSYMLINKS)
{
__set_errno (ELOOP);
goto error;
}
buf = malloca (path_max);
if (!buf)
{
errno = ENOMEM;
goto error;
}
n = __readlink (rpath, buf, path_max - 1);
if (n < 0)
{
int saved_errno = errno;
freea (buf);
errno = saved_errno;
goto error;
}
buf[n] = '\0';
if (!extra_buf)
{
extra_buf = malloca (path_max);
if (!extra_buf)
{
freea (buf);
errno = ENOMEM;
goto error;
}
}
len = strlen (end);
if ((long int) (n + len) >= path_max)
{
freea (buf);
__set_errno (ENAMETOOLONG);
goto error;
}
/* Careful here, end may be a pointer into extra_buf... */
memmove (&extra_buf[n], end, len + 1);
name = end = memcpy (extra_buf, buf, n);
if (IS_ABSOLUTE_FILE_NAME (buf))
{
size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
if (pfxlen)
memcpy (rpath, buf, pfxlen);
dest = rpath + pfxlen;
*dest++ = '/'; /* It's an absolute symlink */
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
*dest++ = '/';
*dest = '\0';
}
/* Install the new prefix to be in effect hereafter. */
prefix_len = pfxlen;
}
else
{
/* Back up to previous component, ignore if at root
already: */
if (dest > rpath + prefix_len + 1)
for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1
&& ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
dest++;
}
}
else if (!S_ISDIR (st.st_mode) && *end != '\0')
{
__set_errno (ENOTDIR);
goto error;
}
}
}
if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1]))
--dest;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len
&& ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
*dest = '\0';
if (extra_buf)
freea (extra_buf);
return rpath;
error:
{
int saved_errno = errno;
if (extra_buf)
freea (extra_buf);
if (resolved == NULL)
free (rpath);
errno = saved_errno;
}
return NULL;
}
static
#endif
char *
compute_curr_prefix (const char *orig_installprefix,
const char *orig_installdir,
const char *curr_pathname)
{
char *curr_installdir;
const char *rel_installdir;
if (curr_pathname == NULL)
return NULL;
/* Determine the relative installation directory, relative to the prefix.
This is simply the difference between orig_installprefix and
orig_installdir. */
if (strncmp (orig_installprefix, orig_installdir, strlen (orig_installprefix))
!= 0)
/* Shouldn't happen - nothing should be installed outside $(prefix). */
return NULL;
rel_installdir = orig_installdir + strlen (orig_installprefix);
/* Determine the current installation directory. */
{
const char *p_base = curr_pathname + FILE_SYSTEM_PREFIX_LEN (curr_pathname);
const char *p = curr_pathname + strlen (curr_pathname);
char *q;
while (p > p_base)
{
p--;
if (ISSLASH (*p))
break;
}
q = (char *) xmalloc (p - curr_pathname + 1);
#ifdef NO_XMALLOC
if (q == NULL)
return NULL;
#endif
memcpy (q, curr_pathname, p - curr_pathname);
q[p - curr_pathname] = '\0';
curr_installdir = q;
}
/* Compute the current installation prefix by removing the trailing
rel_installdir from it. */
{
const char *rp = rel_installdir + strlen (rel_installdir);
const char *cp = curr_installdir + strlen (curr_installdir);
const char *cp_base =
curr_installdir + FILE_SYSTEM_PREFIX_LEN (curr_installdir);
while (rp > rel_installdir && cp > cp_base)
{
bool same = false;
const char *rpi = rp;
const char *cpi = cp;
while (rpi > rel_installdir && cpi > cp_base)
{
rpi--;
cpi--;
if (ISSLASH (*rpi) || ISSLASH (*cpi))
{
if (ISSLASH (*rpi) && ISSLASH (*cpi))
same = true;
break;
}
/* Do case-insensitive comparison if the file system is always or
often case-insensitive. It's better to accept the comparison
if the difference is only in case, rather than to fail. */
#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__ || defined __EMX__ || defined __DJGPP__
/* Native Windows, Cygwin, OS/2, DOS - case insignificant file system */
if ((*rpi >= 'a' && *rpi <= 'z' ? *rpi - 'a' + 'A' : *rpi)
!= (*cpi >= 'a' && *cpi <= 'z' ? *cpi - 'a' + 'A' : *cpi))
break;
#else
if (*rpi != *cpi)
break;
#endif
}
if (!same)
break;
/* The last pathname component was the same. opi and cpi now point
to the slash before it. */
rp = rpi;
cp = cpi;
}
if (rp > rel_installdir)
{
/* Unexpected: The curr_installdir does not end with rel_installdir. */
free (curr_installdir);
return NULL;
}
{
size_t curr_prefix_len = cp - curr_installdir;
char *curr_prefix;
curr_prefix = (char *) xmalloc (curr_prefix_len + 1);
#ifdef NO_XMALLOC
if (curr_prefix == NULL)
{
free (curr_installdir);
return NULL;
}
#endif
memcpy (curr_prefix, curr_installdir, curr_prefix_len);
curr_prefix[curr_prefix_len] = '\0';
free (curr_installdir);
return curr_prefix;
}
}
}
char *
canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode)
{
char *rname, *dest, *extra_buf = NULL;
char const *start;
char const *end;
char const *rname_limit;
size_t extra_len = 0;
Hash_table *ht = NULL;
int saved_errno;
int can_flags = can_mode & ~CAN_MODE_MASK;
bool logical = can_flags & CAN_NOLINKS;
size_t prefix_len;
can_mode &= CAN_MODE_MASK;
if (MULTIPLE_BITS_SET (can_mode))
{
errno = EINVAL;
return NULL;
}
if (name == NULL)
{
errno = EINVAL;
return NULL;
}
if (name[0] == '\0')
{
errno = ENOENT;
return NULL;
}
/* This is always zero for Posix hosts, but can be 2 for MS-Windows
and MS-DOS X:/foo/bar file names. */
prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
if (!IS_ABSOLUTE_FILE_NAME (name))
{
rname = xgetcwd ();
if (!rname)
return NULL;
dest = strchr (rname, '\0');
if (dest - rname < PATH_MAX)
{
char *p = xrealloc (rname, PATH_MAX);
dest = p + (dest - rname);
rname = p;
rname_limit = rname + PATH_MAX;
}
else
{
rname_limit = dest;
}
start = name;
prefix_len = FILE_SYSTEM_PREFIX_LEN (rname);
}
else
{
rname = xmalloc (PATH_MAX);
rname_limit = rname + PATH_MAX;
dest = rname;
if (prefix_len)
{
memcpy (rname, name, prefix_len);
dest += prefix_len;
}
*dest++ = '/';
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len)
*dest++ = '/';
*dest = '\0';
}
start = name + prefix_len;
}
for ( ; *start; start = end)
{
/* Skip sequence of multiple file name separators. */
while (ISSLASH (*start))
++start;
/* Find end of component. */
for (end = start; *end && !ISSLASH (*end); ++end)
/* Nothing. */;
if (end - start == 0)
break;
else if (end - start == 1 && start[0] == '.')
/* nothing */;
else if (end - start == 2 && start[0] == '.' && start[1] == '.')
{
/* Back up to previous component, ignore if at root already. */
if (dest > rname + prefix_len + 1)
for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
}
else
{
struct stat st;
if (!ISSLASH (dest[-1]))
*dest++ = '/';
if (dest + (end - start) >= rname_limit)
{
ptrdiff_t dest_offset = dest - rname;
size_t new_size = rname_limit - rname;
if (end - start + 1 > PATH_MAX)
new_size += end - start + 1;
else
new_size += PATH_MAX;
rname = xrealloc (rname, new_size);
rname_limit = rname + new_size;
dest = rname + dest_offset;
}
dest = memcpy (dest, start, end - start);
dest += end - start;
*dest = '\0';
if (logical && (can_mode == CAN_MISSING))
{
/* Avoid the stat in this case as it's inconsequential.
i.e. we're neither resolving symlinks or testing
component existence. */
st.st_mode = 0;
}
else if ((logical ? stat (rname, &st) : lstat (rname, &st)) != 0)
{
saved_errno = errno;
if (can_mode == CAN_EXISTING)
goto error;
if (can_mode == CAN_ALL_BUT_LAST)
{
if (end[strspn (end, SLASHES)] || saved_errno != ENOENT)
goto error;
continue;
}
st.st_mode = 0;
}
if (S_ISLNK (st.st_mode))
{
char *buf;
size_t n, len;
/* Detect loops. We cannot use the cycle-check module here,
since it's actually possible to encounter the same symlink
more than once in a given traversal. However, encountering
the same symlink,NAME pair twice does indicate a loop. */
if (seen_triple (&ht, name, &st))
{
if (can_mode == CAN_MISSING)
continue;
saved_errno = ELOOP;
goto error;
}
buf = areadlink_with_size (rname, st.st_size);
if (!buf)
{
if (can_mode == CAN_MISSING && errno != ENOMEM)
continue;
saved_errno = errno;
goto error;
}
n = strlen (buf);
len = strlen (end);
if (!extra_len)
{
extra_len =
((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX;
extra_buf = xmalloc (extra_len);
}
else if ((n + len + 1) > extra_len)
{
extra_len = n + len + 1;
extra_buf = xrealloc (extra_buf, extra_len);
}
/* Careful here, end may be a pointer into extra_buf... */
memmove (&extra_buf[n], end, len + 1);
name = end = memcpy (extra_buf, buf, n);
if (IS_ABSOLUTE_FILE_NAME (buf))
{
size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
if (pfxlen)
memcpy (rname, buf, pfxlen);
dest = rname + pfxlen;
*dest++ = '/'; /* It's an absolute symlink */
if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
{
if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen)
*dest++ = '/';
*dest = '\0';
}
/* Install the new prefix to be in effect hereafter. */
prefix_len = pfxlen;
}
else
{
/* Back up to previous component, ignore if at root
already: */
if (dest > rname + prefix_len + 1)
for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
continue;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
&& ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
dest++;
}
free (buf);
}
else
{
if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING))
{
saved_errno = ENOTDIR;
goto error;
}
}
}
}
if (dest > rname + prefix_len + 1 && ISSLASH (dest[-1]))
--dest;
if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && !prefix_len
&& ISSLASH (*dest) && !ISSLASH (dest[1]))
dest++;
*dest = '\0';
if (rname_limit != dest + 1)
rname = xrealloc (rname, dest - rname + 1);
free (extra_buf);
if (ht)
hash_free (ht);
return rname;
error:
free (extra_buf);
free (rname);
if (ht)
hash_free (ht);
errno = saved_errno;
return NULL;
}
