New file (function extracted from ln.c).

lib/same.c

@@ -0,0 +1,75 @@
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#if HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#include "same.h"
+#include "dirname.h"
+#include "error.h"
+
+#if ENABLE_NLS
+# include <libintl.h>
+# define _(Text) gettext (Text)
+#else
+# define _(Text) Text
+#endif
+
+#define STREQ(a, b) (strcmp ((a), (b)) == 0)
+
+#ifndef HAVE_DECL_FREE
+void free ();
+#endif
+
+char *base_name PARAMS ((char const *));
+
+#define SAME_INODE(Stat_buf_1, Stat_buf_2) \
+  ((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
+   && (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
+
+/* Return nonzero if SOURCE and DEST point to the same name in the same
+   directory.  */
+
+int
+same_name (const char *source, const char *dest)
+{
+  struct stat source_dir_stats;
+  struct stat dest_dir_stats;
+  char *source_dirname, *dest_dirname;
+
+  source_dirname = dir_name (source);
+  dest_dirname = dir_name (dest);
+  if (source_dirname == NULL || dest_dirname == NULL)
+    error (1, 0, _("virtual memory exhausted"));
+
+  if (stat (source_dirname, &source_dir_stats))
+    {
+      /* Shouldn't happen.  */
+      error (1, errno, "%s", source_dirname);
+    }
+
+  if (stat (dest_dirname, &dest_dir_stats))
+    {
+      /* Shouldn't happen.  */
+      error (1, errno, "%s", dest_dirname);
+    }
+
+  free (source_dirname);
+  free (dest_dirname);
+
+  return (SAME_INODE (source_dir_stats, dest_dir_stats)
+	  && STREQ (base_name (source), base_name (dest)));
+}