Imported from ../bash-2.01.tar.gz.

hashcmd.c

@@ -0,0 +1,191 @@
+/* hashcmd.c - functions for managing a hash table mapping command names to
+	       full pathnames. */
+
+/* Copyright (C) 1997 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+    Bash 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 1, or (at your option) any later
+    version.
+
+    Bash 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 Bash; see the file COPYING.  If not, write to the Free Software
+    Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <config.h>
+
+#include "bashtypes.h"
+#include "posixstat.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "bashansi.h"
+
+#include "shell.h"
+#include "execute_cmd.h"
+#include "hashcmd.h"
+
+extern int hashing_enabled;
+
+static int hashing_initialized = 0;
+
+HASH_TABLE *hashed_filenames;
+
+void
+initialize_filename_hashing ()
+{
+  if (hashing_initialized == 0)
+    {
+      hashed_filenames = make_hash_table (FILENAME_HASH_BUCKETS);
+      hashing_initialized = 1;
+    }
+}
+
+static void
+free_filename_data (data)
+     char *data;
+{
+  free (((PATH_DATA *)data)->path);
+  free (data);
+}
+
+void
+flush_hashed_filenames ()
+{
+  if (hashed_filenames)
+    flush_hash_table (hashed_filenames, free_filename_data);
+}
+
+/* Remove FILENAME from the table of hashed commands. */
+void
+remove_hashed_filename (filename)
+     char *filename;
+{
+  register BUCKET_CONTENTS *item;
+
+  if (hashing_enabled == 0 || hashed_filenames == 0)
+    return;
+
+  item = remove_hash_item (filename, hashed_filenames);
+  if (item)
+    {
+      if (item->data)
+	free_filename_data (item->data);
+      free (item->key);
+      free (item);
+    }
+}
+
+/* Place FILENAME (key) and FULL_PATHNAME (data->path) into the
+   hash table.  CHECK_DOT if non-null is for future calls to
+   find_hashed_filename (); it means that this file was found
+   in a directory in $PATH that is not an absolute pathname.
+   FOUND is the initial value for times_found. */
+void
+remember_filename (filename, full_pathname, check_dot, found)
+     char *filename, *full_pathname;
+     int check_dot, found;
+{
+  register BUCKET_CONTENTS *item;
+
+  if (hashing_enabled == 0)
+    return;
+
+  if (hashed_filenames == 0 || hashing_initialized == 0)
+    initialize_filename_hashing ();
+
+  item = add_hash_item (filename, hashed_filenames);
+  if (item->data)
+    free (pathdata(item)->path);
+  else
+    {
+      item->key = savestring (filename);
+      item->data = xmalloc (sizeof (PATH_DATA));
+    }
+  pathdata(item)->path = savestring (full_pathname);
+  pathdata(item)->flags = 0;
+  if (check_dot)
+    pathdata(item)->flags |= HASH_CHKDOT;
+  if (*full_pathname != '/')
+    pathdata(item)->flags |= HASH_RELPATH;
+  item->times_found = found;
+}
+
+/* Return the full pathname that FILENAME hashes to.  If FILENAME
+   is hashed, but (data->flags & HASH_CHKDOT) is non-zero, check
+   ./FILENAME and return that if it is executable.  This always
+   returns a newly-allocated string; the caller is responsible
+   for freeing it. */
+char *
+find_hashed_filename (filename)
+     char *filename;
+{
+  register BUCKET_CONTENTS *item;
+  char *path, *dotted_filename, *tail;
+  int same;
+
+  if (hashing_enabled == 0 || hashed_filenames == 0)
+    return ((char *)NULL);
+
+  item = find_hash_item (filename, hashed_filenames);
+
+  if (item == NULL)
+    return ((char *)NULL);
+
+  /* If this filename is hashed, but `.' comes before it in the path,
+     see if ./filename is executable.  If the hashed value is not an
+     absolute pathname, see if ./`hashed-value' exists. */
+  path = pathdata(item)->path;
+  if (pathdata(item)->flags & (HASH_CHKDOT|HASH_RELPATH))
+    {
+      tail = (pathdata(item)->flags & HASH_RELPATH) ? path : filename;
+      dotted_filename = xmalloc (3 + strlen (tail));
+      dotted_filename[0] = '.'; dotted_filename[1] = '/';
+      strcpy (dotted_filename + 2, tail);
+
+      if (executable_file (dotted_filename))
+	return (dotted_filename);
+
+      free (dotted_filename);
+
+#if 0
+      if (pathdata(item)->flags & HASH_RELPATH)
+	return ((char *)NULL);
+#endif
+
+      /* Watch out.  If this file was hashed to "./filename", and
+	 "./filename" is not executable, then return NULL. */
+
+      /* Since we already know "./filename" is not executable, what
+	 we're really interested in is whether or not the `path'
+	 portion of the hashed filename is equivalent to the current
+	 directory, but only if it starts with a `.'.  (This catches
+	 ./. and so on.)  same_file () tests general Unix file
+	 equivalence -- same device and inode. */
+      if (*path == '.')
+	{
+	  same = 0;
+	  tail = (char *)strrchr (path, '/');
+
+	  if (tail)
+	    {
+	      *tail = '\0';
+	      same = same_file (".", path, (struct stat *)NULL, (struct stat *)NULL);
+	      *tail = '/';
+	    }
+
+	  return same ? (char *)NULL : savestring (path);
+	}
+    }
+
+  return (savestring (path));
+}