add directory gnu

gnu/glibc/glibc-1.03/sysdeps/posix/getcwd.c

@@ -0,0 +1,194 @@
+/* Copyright (C) 1991 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.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* 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 *
+DEFUN(getcwd, (buf, size), char *buf AND size_t size)
+{
+  static CONST char dots[]
+    = "../../../../../../../../../../../../../../../../../../../../../../../\
+../../../../../../../../../../../../../../../../../../../../../../../../../../\
+../../../../../../../../../../../../../../../../../../../../../../../../../..";
+  CONST char *dotp, *dotlist;
+  size_t dotsize;
+  dev_t rootdev, thisdev;
+  ino_t rootino, thisino;
+  char path[PATH_MAX + 1];
+  register char *pathp;
+  struct stat st;
+
+  if (buf != NULL && size == 0)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+  pathp = &path[sizeof(path)];
+  *--pathp = '\0';
+
+  if (stat (".", &st) < 0)
+    return NULL;
+  thisdev = st.st_dev;
+  thisino = st.st_ino;
+
+  if (stat ("/", &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) 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 (stat (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_fileno == 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 (stat (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
+	{
+	  pathp -= d->d_namlen;
+	  (void) memcpy (pathp, d->d_name, d->d_namlen);
+	  *--pathp = '/';
+	  (void) closedir (dirstream);
+	}
+
+      thisdev = dotdev;
+      thisino = dotino;
+    }
+
+  if (pathp == &path[sizeof(path) - 1])
+    *--pathp = '/';
+
+  if (dotlist != dots)
+    free ((PTR) dotlist);
+
+  {
+    size_t len = &path[sizeof(path)] - pathp;
+    if (buf == NULL)
+      {
+	if (len < (size_t) size)
+	  len = size;
+	buf = (char *) malloc(len);
+	if (buf == NULL)
+	  return NULL;
+      }
+    else if ((size_t) size < len)
+      {
+	errno = ERANGE;
+	return NULL;
+      }
+    (void) memcpy((PTR) buf, (PTR) pathp, len);
+  }
+
+  return buf;
+
+ lose:
+  if (dotlist != dots)
+    free ((PTR) dotlist);
+  return NULL;
+}