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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/posix/getcwd.c
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initial import
Diffstat (limited to 'sysdeps/posix/getcwd.c')
-rw-r--r--sysdeps/posix/getcwd.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/sysdeps/posix/getcwd.c b/sysdeps/posix/getcwd.c
new file mode 100644
index 0000000..7b992a9
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+++ b/sysdeps/posix/getcwd.c
@@ -0,0 +1,366 @@
+/* Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+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., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+/* Wants:
+ AC_STDC_HEADERS
+ AC_DIR_HEADER
+ AC_UNISTD_H
+ AC_MEMORY_H
+ AC_CONST
+ AC_ALLOCA
+ */
+
+/* AIX requires this to be the first thing in the file. */
+#if defined (_AIX) && !defined (__GNUC__)
+ #pragma alloca
+#endif
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifdef STDC_HEADERS
+#include <stddef.h>
+#endif
+
+#if !defined(__GNU_LIBRARY__) && !defined(STDC_HEADERS)
+extern int errno;
+#endif
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+#if defined (USGr3) && !defined (DIRENT)
+#define DIRENT
+#endif /* USGr3 */
+#if defined (Xenix) && !defined (SYSNDIR)
+#define SYSNDIR
+#endif /* Xenix */
+
+#if defined (POSIX) || defined (DIRENT) || defined (__GNU_LIBRARY__)
+#include <dirent.h>
+#ifndef __GNU_LIBRARY__
+#define D_NAMLEN(d) strlen((d)->d_name)
+#else
+#define HAVE_D_NAMLEN
+#define D_NAMLEN(d) ((d)->d_namlen)
+#endif
+#else /* not POSIX or DIRENT */
+#define dirent direct
+#define D_NAMLEN(d) ((d)->d_namlen)
+#define HAVE_D_NAMLEN
+#if defined (USG) && !defined (sgi)
+#if defined (SYSNDIR)
+#include <sys/ndir.h>
+#else /* Not SYSNDIR */
+#include "ndir.h"
+#endif /* SYSNDIR */
+#else /* not USG */
+#include <sys/dir.h>
+#endif /* USG */
+#endif /* POSIX or DIRENT or __GNU_LIBRARY__ */
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#if (defined (STDC_HEADERS) || defined (__GNU_LIBRARY__) \
+ || defined (POSIX))
+#include <stdlib.h>
+#include <string.h>
+#define ANSI_STRING
+#else /* No standard headers. */
+
+#ifdef USG
+
+#include <string.h>
+#ifdef NEED_MEMORY_H
+#include <memory.h>
+#endif
+#define ANSI_STRING
+
+#else /* Not USG. */
+
+#ifdef NeXT
+
+#include <string.h>
+
+#else /* Not NeXT. */
+
+#include <strings.h>
+
+#ifndef bcmp
+extern int bcmp ();
+#endif
+#ifndef bzero
+extern void bzero ();
+#endif
+#ifndef bcopy
+extern void bcopy ();
+#endif
+
+#endif /* NeXT. */
+
+#endif /* USG. */
+
+extern char *malloc (), *realloc ();
+extern void free ();
+
+#endif /* Standard headers. */
+
+#ifndef ANSI_STRING
+#define memcpy(d, s, n) bcopy((s), (d), (n))
+#define memmove memcpy
+#endif /* Not ANSI_STRING. */
+
+#if !defined(__alloca) && !defined(__GNU_LIBRARY__)
+
+#ifdef __GNUC__
+#undef alloca
+#define alloca(n) __builtin_alloca (n)
+#else /* Not GCC. */
+#if defined (sparc) || defined (HAVE_ALLOCA_H)
+#include <alloca.h>
+#else /* Not sparc or HAVE_ALLOCA_H. */
+#ifndef _AIX
+extern char *alloca ();
+#endif /* Not _AIX. */
+#endif /* sparc or HAVE_ALLOCA_H. */
+#endif /* GCC. */
+
+#define __alloca alloca
+
+#endif
+
+#if (defined (HAVE_LIMITS_H) || defined (STDC_HEADERS) || \
+ defined (__GNU_LIBRARY__))
+#include <limits.h>
+#else
+#include <sys/param.h>
+#endif
+
+#ifndef PATH_MAX
+#ifdef MAXPATHLEN
+#define PATH_MAX MAXPATHLEN
+#else
+#define PATH_MAX 1024
+#endif
+#endif
+
+#ifndef STDC_HEADERS
+#undef size_t
+#define size_t unsigned int
+#endif
+
+#if !__STDC__ && !defined (const)
+#define const
+#endif
+
+#ifndef __GNU_LIBRARY__
+#define __lstat stat
+#endif
+
+/* Get the pathname 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 (buf, size)
+ char *buf;
+ size_t size;
+{
+ static const char dots[]
+ = "../../../../../../../../../../../../../../../../../../../../../../../\
+../../../../../../../../../../../../../../../../../../../../../../../../../../\
+../../../../../../../../../../../../../../../../../../../../../../../../../..";
+ const char *dotp, *dotlist;
+ size_t dotsize;
+ dev_t rootdev, thisdev;
+ ino_t rootino, thisino;
+ char *path;
+ register char *pathp;
+ struct stat st;
+
+ if (size == 0)
+ {
+ if (buf != NULL)
+ {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ size = PATH_MAX + 1;
+ }
+
+ if (buf != NULL)
+ path = buf;
+ else
+ {
+ path = malloc (size);
+ if (path == NULL)
+ return NULL;
+ }
+
+ pathp = path + size;
+ *--pathp = '\0';
+
+ if (__lstat (".", &st) < 0)
+ return NULL;
+ thisdev = st.st_dev;
+ thisino = st.st_ino;
+
+ if (__lstat ("/", &st) < 0)
+ return NULL;
+ rootdev = st.st_dev;
+ rootino = st.st_ino;
+
+ dotsize = sizeof (dots) - 1;
+ dotp = &dots[sizeof (dots)];
+ dotlist = dots;
+ while (!(thisdev == rootdev && thisino == rootino))
+ {
+ register DIR *dirstream;
+ register struct dirent *d;
+ dev_t dotdev;
+ ino_t dotino;
+ char mount_point;
+
+ /* Look at the parent directory. */
+ if (dotp == dotlist)
+ {
+ /* My, what a deep directory tree you have, Grandma. */
+ char *new;
+ if (dotlist == dots)
+ {
+ new = malloc (dotsize * 2 + 1);
+ if (new == NULL)
+ return NULL;
+ memcpy (new, dots, dotsize);
+ }
+ else
+ {
+ new = realloc ((__ptr_t) dotlist, dotsize * 2 + 1);
+ if (new == NULL)
+ goto lose;
+ }
+ memcpy (&new[dotsize], new, dotsize);
+ dotp = &new[dotsize];
+ dotsize *= 2;
+ new[dotsize] = '\0';
+ dotlist = new;
+ }
+
+ dotp -= 3;
+
+ /* Figure out if this directory is a mount point. */
+ if (__lstat (dotp, &st) < 0)
+ goto lose;
+ dotdev = st.st_dev;
+ dotino = st.st_ino;
+ mount_point = dotdev != thisdev;
+
+ /* Search for the last directory. */
+ dirstream = opendir (dotp);
+ if (dirstream == NULL)
+ goto lose;
+ while ((d = readdir (dirstream)) != NULL)
+ {
+ if (d->d_name[0] == '.' &&
+ (d->d_namlen == 1 || (d->d_namlen == 2 && d->d_name[1] == '.')))
+ continue;
+ if (mount_point || d->d_ino == thisino)
+ {
+ char *name = __alloca (dotlist + dotsize - dotp +
+ 1 + d->d_namlen + 1);
+ memcpy (name, dotp, dotlist + dotsize - dotp);
+ name[dotlist + dotsize - dotp] = '/';
+ memcpy (&name[dotlist + dotsize - dotp + 1],
+ d->d_name, d->d_namlen + 1);
+ if (__lstat (name, &st) < 0)
+ {
+ int save = errno;
+ (void) closedir (dirstream);
+ errno = save;
+ goto lose;
+ }
+ if (st.st_dev == thisdev && st.st_ino == thisino)
+ break;
+ }
+ }
+ if (d == NULL)
+ {
+ int save = errno;
+ (void) closedir (dirstream);
+ errno = save;
+ goto lose;
+ }
+ else
+ {
+ if (pathp - path < d->d_namlen + 1)
+ {
+ if (buf != NULL)
+ {
+ errno = ERANGE;
+ return NULL;
+ }
+ else
+ {
+ size *= 2;
+ buf = realloc (path, size);
+ if (buf == NULL)
+ {
+ (void) closedir (dirstream);
+ free (path);
+ errno = ENOMEM; /* closedir might have changed it. */
+ return NULL;
+ }
+ pathp = &buf[pathp - path];
+ path = buf;
+ }
+ }
+ pathp -= d->d_namlen;
+ (void) memcpy (pathp, d->d_name, d->d_namlen);
+ *--pathp = '/';
+ (void) closedir (dirstream);
+ }
+
+ thisdev = dotdev;
+ thisino = dotino;
+ }
+
+ if (pathp == &path[size - 1])
+ *--pathp = '/';
+
+ if (dotlist != dots)
+ free ((__ptr_t) dotlist);
+
+ memmove (path, pathp, path + size - pathp);
+ return path;
+
+ lose:
+ if (dotlist != dots)
+ free ((__ptr_t) dotlist);
+ return NULL;
+}