--- /dev/null
+/* xgetcwd.c -- return current directory with unlimited length
+ Copyright (C) 1992 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* Written by David MacKenzie, djm@gnu.ai.mit.edu. */
+
+#include <errno.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#if defined(_POSIX_VERSION) || defined(STDC_HEADERS) || defined(HAVE_LIMITS_H)
+#include <limits.h>
+#endif /* !_POSIX_VERSION && !STDC_HEADERS && !HAVE_LIMITS_H */
+
+#ifndef _POSIX_SOURCE
+#include <sys/param.h>
+#endif
+
+#ifndef _POSIX_PATH_MAX
+#define _POSIX_PATH_MAX 255
+#endif
+
+#ifndef PATH_MAX
+#ifdef _PC_PATH_MAX
+#define PATH_MAX pathconf ("/", _PC_PATH_MAX)
+#else /* !_PC_PATH_MAX */
+#ifdef MAXPATHLEN
+#define PATH_MAX MAXPATHLEN
+#else /* not MAXPATHLEN */
+#define PATH_MAX _POSIX_PATH_MAX
+#endif /* MAXPATHLEN */
+#endif /* !_PC_PATH_MAX */
+#endif /* !PATH_MAX */
+
+#if !defined(_POSIX_VERSION) && !defined(USG)
+char *getwd ();
+#define getcwd(buf, max) getwd (buf)
+#else
+char *getcwd ();
+#endif
+
+/* Amount to increase buffer size by in each try. */
+#define PATH_INCR 32
+
+char *xmalloc ();
+char *xrealloc ();
+
+/* Return the current directory, newly allocated, arbitrarily long.
+ Return NULL and set errno on error. */
+
+char *
+xgetcwd ()
+{
+ char *cwd;
+ char *ret;
+ long path_max;
+
+ errno = 0;
+#ifdef _POSIX_VERSION
+ path_max = PATH_MAX;
+ if (path_max < 0)
+ {
+ if (errno)
+ return NULL;
+ path_max = _POSIX_PATH_MAX;
+ }
+#else /* !_POSIX_VERSION */
+ path_max = PATH_MAX;
+#endif /* !_POSIX_VERSION */
+ path_max += 2; /* The getcwd docs say to do this. */
+
+ cwd = (char *) xmalloc (path_max);
+
+ errno = 0;
+ while ((ret = getcwd (cwd, path_max)) == NULL && errno == ERANGE)
+ {
+ path_max += PATH_INCR;
+ cwd = xrealloc (cwd, path_max);
+ errno = 0;
+ }
+
+ if (ret == NULL)
+ {
+ int save_errno = errno;
+ free (cwd);
+ errno = save_errno;
+ return NULL;
+ }
+ return cwd;
+}