116 lines
3.0 KiB
C
116 lines
3.0 KiB
C
/* Determine current working directory. Linux version.
|
|
Copyright (C) 1997 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <errno.h>
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
|
|
/* The "proc" filesystem provides an easy method to retrieve the value.
|
|
For each process, the corresponding directory contains a symbolic link
|
|
named `cwd'. Reading the content of this link immediate gives us the
|
|
information. But we have to take care for systems which do not have
|
|
the proc filesystem mounted. Use the POSIX implementation in this case. */
|
|
static char *generic_getcwd (char *buf, size_t size) internal_function;
|
|
|
|
char *
|
|
__getcwd (char *buf, size_t size)
|
|
{
|
|
static int no_new_dcache = 0;
|
|
int save_errno;
|
|
char *path;
|
|
int n;
|
|
char *result;
|
|
size_t alloc_size = size;
|
|
|
|
if (no_new_dcache)
|
|
return generic_getcwd (buf, size);
|
|
|
|
if (size == 0)
|
|
{
|
|
if (buf != NULL)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return NULL;
|
|
}
|
|
|
|
alloc_size = PATH_MAX + 1;
|
|
}
|
|
|
|
if (buf != NULL)
|
|
path = buf;
|
|
else
|
|
{
|
|
path = malloc (alloc_size);
|
|
if (path == NULL)
|
|
return NULL;
|
|
}
|
|
|
|
save_errno = errno;
|
|
|
|
n = __readlink ("/proc/self/cwd", path, alloc_size - 1);
|
|
if (n != -1)
|
|
{
|
|
if (path[0] == '/')
|
|
{
|
|
if (n >= alloc_size - 1)
|
|
{
|
|
if (buf == NULL)
|
|
free (path);
|
|
return NULL;
|
|
}
|
|
|
|
path[n] = '\0';
|
|
return buf ?: (char *) realloc (path, (size_t) n + 1);
|
|
}
|
|
else
|
|
no_new_dcache = 1;
|
|
}
|
|
|
|
/* Set to no_new_dcache only if error indicates that proc doesn't exist. */
|
|
if (errno != EACCES && errno != ENAMETOOLONG)
|
|
no_new_dcache = 1;
|
|
|
|
/* Something went wrong. Restore the error number and use the generic
|
|
version. */
|
|
__set_errno (save_errno);
|
|
|
|
/* Don't put restrictions on the length of the path unless the user does. */
|
|
if (size == 0)
|
|
{
|
|
free (path);
|
|
path = NULL;
|
|
}
|
|
|
|
result = generic_getcwd (path, size);
|
|
|
|
if (result == NULL && buf == NULL && size != 0)
|
|
free (path);
|
|
|
|
return result;
|
|
}
|
|
weak_alias (__getcwd, getcwd)
|
|
|
|
/* Get the code for the generic version. */
|
|
#define GETCWD_STORAGE_CLASS static internal_function
|
|
#define __getcwd generic_getcwd
|
|
#include <sysdeps/posix/getcwd.c>
|