import newlib-2000-02-17 snapshot

1 files changed, 265 insertions, 0 deletions

diff --git a/newlib/libc/unix/getcwd.c b/newlib/libc/unix/getcwd.c
new file mode 100644
index 000000000..ee53536ed
--- /dev/null
+++ b/newlib/libc/unix/getcwd.c
@@ -0,0 +1,265 @@
+/*
+ * Copyright (c) 1989, 1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)getcwd.c	5.11 (Berkeley) 2/24/91";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <reent.h>
+#include <_syslist.h>
+
+#define bcopy(a,b,c)	memmove (b,a,c)
+
+#define	ISDOT(dp) \
+	(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
+	    dp->d_name[1] == '.' && dp->d_name[2] == '\0'))
+
+#ifndef _REENT_ONLY
+
+char *
+getcwd (pt, size)
+     char *pt;
+     size_t size;
+{
+  register struct dirent *dp;
+  register DIR *dir;
+  register dev_t dev;
+  register ino_t ino;
+  register int first;
+  register char *bpt, *bup;
+  struct stat s;
+  dev_t root_dev;
+  ino_t root_ino;
+  size_t ptsize, upsize;
+  int save_errno;
+  char *ept, *eup, *up;
+
+  /*
+   * If no buffer specified by the user, allocate one as necessary.
+   * If a buffer is specified, the size has to be non-zero.  The path
+   * is built from the end of the buffer backwards.
+   */
+
+  if (pt)
+    {
+      ptsize = 0;
+      if (!size)
+	{
+	  errno = EINVAL;
+	  return (char *) NULL;
+	}
+      ept = pt + size;
+    }
+  else
+    {
+      if (!(pt = (char *) malloc (ptsize = 1024 - 4)))
+	{
+	  return (char *) NULL;
+	}
+      ept = pt + ptsize;
+    }
+  bpt = ept - 1;
+  *bpt = '\0';
+
+  /*
+   * Allocate bytes (1024 - malloc space) for the string of "../"'s.
+   * Should always be enough (it's 340 levels).  If it's not, allocate
+   * as necessary.  Special * case the first stat, it's ".", not "..".
+   */
+
+  if (!(up = (char *) malloc (upsize = 1024 - 4)))
+    {
+      goto err;
+    }
+  eup = up + MAXPATHLEN;
+  bup = up;
+  up[0] = '.';
+  up[1] = '\0';
+
+  /* Save root values, so know when to stop. */
+  if (stat ("/", &s))
+    goto err;
+  root_dev = s.st_dev;
+  root_ino = s.st_ino;
+
+  errno = 0;			/* XXX readdir has no error return. */
+
+  for (first = 1;; first = 0)
+    {
+      /* Stat the current level. */
+      if (_stat (up, &s))
+	goto err;
+
+      /* Save current node values. */
+      ino = s.st_ino;
+      dev = s.st_dev;
+
+      /* Check for reaching root. */
+      if (root_dev == dev && root_ino == ino)
+	{
+	  *--bpt = '/';
+	  /*
+	   * It's unclear that it's a requirement to copy the
+	   * path to the beginning of the buffer, but it's always
+	   * been that way and stuff would probably break.
+	   */
+	  (void) bcopy (bpt, pt, ept - bpt);
+	  free (up);
+	  return pt;
+	}
+
+      /*
+       * Build pointer to the parent directory, allocating memory
+       * as necessary.  Max length is 3 for "../", the largest
+       * possible component name, plus a trailing NULL.
+       */
+
+      if (bup + 3 + MAXNAMLEN + 1 >= eup)
+	{
+	  if (!(up = (char *) realloc (up, upsize *= 2)))
+	    {
+	      goto err;
+	    }
+	  bup = up;
+	  eup = up + upsize;
+	}
+      *bup++ = '.';
+      *bup++ = '.';
+      *bup = '\0';
+
+      /* Open and stat parent directory. */
+      if (!(dir = _opendir (up)) || _fstat (__dirfd (dir), &s))
+	goto err;
+
+      /* Add trailing slash for next directory. */
+      *bup++ = '/';
+
+      /*
+       * If it's a mount point, have to stat each element because
+       * the inode number in the directory is for the entry in the
+       * parent directory, not the inode number of the mounted file.
+       */
+
+      save_errno = 0;
+      if (s.st_dev == dev)
+	{
+	  for (;;)
+	    {
+	      if (!(dp = _readdir (dir)))
+		goto notfound;
+	      if (dp->d_ino == ino)
+		break;
+	    }
+	}
+      else
+	for (;;)
+	  {
+	    if (!(dp = _readdir (dir)))
+	      goto notfound;
+	    if (ISDOT (dp))
+	      continue;
+	    bcopy (dp->d_name, bup, strlen (dp->d_name) + 1);
+
+	    /* Save the first error for later. */
+	    if (stat (up, &s))
+	      {
+		if (!save_errno)
+		  save_errno = errno;
+		errno = 0;
+		continue;
+	      }
+	    if (s.st_dev == dev && s.st_ino == ino)
+	      break;
+	  }
+
+      /*
+       * Check for length of the current name, preceding slash,
+       * leading slash.
+       */
+
+      if (bpt - pt <= strlen (dp->d_name) + (first ? 1 : 2))
+	{
+	  size_t len, off;
+
+	  if (!ptsize)
+	    {
+	      errno = ERANGE;
+	      goto err;
+	    }
+	  off = bpt - pt;
+	  len = ept - bpt;
+	  if (!(pt = (char *) realloc (pt, ptsize *= 2)))
+	    {
+	      goto err;
+	    }
+	  bpt = pt + off;
+	  ept = pt + ptsize;
+	  (void) bcopy (bpt, ept - len, len);
+	  bpt = ept - len;
+	}
+      if (!first)
+	*--bpt = '/';
+      bpt -= strlen (dp->d_name);
+      bcopy (dp->d_name, bpt, strlen (dp->d_name));
+      (void) _closedir (dir);
+
+      /* Truncate any file name. */
+      *bup = '\0';
+    }
+
+notfound:
+  /*
+   * If readdir set errno, use it, not any saved error; otherwise,
+   * didn't find the current directory in its parent directory, set
+   * errno to ENOENT.
+   */
+
+  if (!errno)
+    errno = save_errno ? save_errno : ENOENT;
+  /* FALLTHROUGH */
+
+err:
+  if (ptsize)
+    free (pt);
+  free (up);
+  return (char *) NULL;
+}
+
+#endif /* _REENT_ONLY */