diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/getcwd.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/getcwd.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/getcwd.c b/sysdeps/unix/sysv/linux/getcwd.c new file mode 100644 index 0000000000..eea0b469e1 --- /dev/null +++ b/sysdeps/unix/sysv/linux/getcwd.c @@ -0,0 +1,94 @@ +/* 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> + +/* #define NDEBUG 1 */ +#include <assert.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); + +char * +__getcwd (char *buf, size_t size) +{ + int save_errno; + char *path; + int n; + char *result; + + if (size == 0) + { + if (buf != NULL) + { + __set_errno (EINVAL); + return NULL; + } + + size = PATH_MAX + 1; + } + + if (buf != NULL) + path = buf; + else + { + path = malloc (size); + if (path == NULL) + return NULL; + } + + save_errno = errno; + n = __readlink ("/proc/self/cwd", path, size); + if (n != -1) + { + if (n >= size) + { + /* This should never happen when we allocate the buffer here. */ + assert (buf == NULL); + __set_errno (ERANGE); + return NULL; + } + path[n] = '\0'; + return buf ?: (char *) realloc (path, (size_t) n + 1); + } + + /* Something went wrong. Restore the error number and use the generic + version. */ + __set_errno (save_errno); + result = generic_getcwd (path, size); + + if (result == NULL && buf == NULL) + free (path); + + return result; +} +weak_alias (__getcwd, getcwd) + +/* Get the code for the generic version. */ +#define GETCWD_STORAGE_CLASS static +#define __getcwd generic_getcwd +#include <sysdeps/posix/getcwd.c> |