# Copyright (C) 2006 Alessandro Di Marco
#
# LazyCD 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; version 2 of the License.
#
# LazyCD 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 LazyCD; if not, write to the Free Software Foundation, Inc., 51
# Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
--- old/bash-3.1/execute_cmd.c	2005-11-05 20:37:21.000000000 +0100
+++ new/bash-3.1/execute_cmd.c	2006-12-18 15:45:03.000000000 +0100
@@ -3511,6 +3511,99 @@
     }
 }

+#define IN_TRIG "/.getin"
+#define OUT_TRIG "/.getout"
+
+#define ADD_TRIGGER(buf, path, name)		\
+  strcpy ((buf), "( builtin cd \"");		\
+  strcat ((buf), (path));			\
+  strcat ((buf), "\" ; .");			\
+  strcat ((buf), (name));			\
+  strcat ((buf), " )");
+
+static char *
+build_trigger_list (old, olde, new, newe)
+     char *old, *olde, *new, *newe;
+{
+  char *buf, *pos, *pos1;
+
+  buf = (char *)xmalloc (strlen (olde) + sizeof IN_TRIG +
+			 strlen (newe) + sizeof OUT_TRIG + 49);
+
+  strcpy (buf, "( ");
+  pos1 = pos = buf + 2;
+
+  strcpy (pos, old);
+  strcat (pos, OUT_TRIG);
+
+  if (executable_file (pos))
+    {
+      ADD_TRIGGER(pos, olde, OUT_TRIG);
+      pos1 = pos + strlen (pos);
+
+      strcat (pos, " && ");
+      pos = pos1 + 4;
+    }
+
+  strcpy (pos, new);
+  strcat (pos, IN_TRIG);
+
+  if (executable_file (pos))
+    {
+      ADD_TRIGGER(pos, newe, IN_TRIG);
+      pos1 = pos + strlen (pos);
+    }
+
+  strcpy (pos1, " )");
+
+  if (strlen (buf) == 4)
+    {
+      xfree (buf);
+      buf = NULL;
+    }
+
+  xfree(olde);
+  xfree(newe);
+
+  return buf;
+}
+
+static char *
+escape_string (string)
+     char *string;
+{
+  char *result;
+  int i, j;
+
+  for (j = i = 0; string[i]; i++)
+    switch (string[i])
+      {
+      case '$':
+      case '`':
+      case '"':
+      case '\\':
+	j++;
+      }
+
+  result = (char *)xmalloc (i + j + 1);
+
+  for (j = i = 0; string[i]; j++, i++)
+    switch (string[i])
+      {
+      case '$':
+      case '`':
+      case '"':
+      case '\\':
+	result[j++] = '\\';
+      default:
+	result[j] = string[i];
+      }
+
+  result[j] = string[i];
+
+  return result;
+}
+
 /* Execute a simple command that is hopefully defined in a disk file
    somewhere.

@@ -3539,8 +3632,8 @@
      struct fd_bitmap *fds_to_close;
      int cmdflags;
 {
-  char *pathname, *command, **args;
-  int nofork;
+  char *lazycd_name, *pathname, *command, **args;
+  int nofork, lazycd_result = 0, lazycd = 0;
   pid_t pid;

   nofork = (cmdflags & CMD_NO_FORK);  /* Don't fork, just exec, if no pipes */
@@ -3569,6 +3662,59 @@
     {
       maybe_make_export_env ();
       put_command_name_into_env (command);
+      lazycd_name = command;
+    }
+  else
+    lazycd_name = pathname;
+
+  if (!find_variable ("LAZY_DISABLE") && is_directory (lazycd_name))
+    {
+      sh_builtin_func_t *builtin;
+      char *oldpwd;
+
+      /* lazycd patch by Alessandro Di Marco <dmr@c0nc3pt.com>
+       * for Amiga (and some Mac) nostalgics only! ;)
+       */
+
+      lazycd = 1;
+      oldpwd = getcwd (0,0);
+
+      builtin = find_shell_builtin ("cd");
+      words = make_word_list (make_bare_word ("cd"),
+			      make_word_list (make_bare_word (lazycd_name),
+					      NULL));
+
+      lazycd_result = execute_builtin (builtin, words, 0, 0);
+      dispose_words (words);
+
+      if (!lazycd_result)
+	{
+	  char *newpwd = getcwd (0,0);
+
+	  if (!oldpwd || !newpwd)
+	    lazycd_result = 1;
+	  else
+	    {
+	      char *cmd = build_trigger_list (oldpwd,
+					      escape_string(oldpwd),
+					      newpwd,
+					      escape_string(newpwd));
+	      if (cmd)
+		{
+		  words = make_word_list (make_bare_word ("sh"),
+				make_word_list (make_bare_word ("-c"),
+					make_word_list (make_bare_word (cmd),
+							NULL)));
+		  xfree (cmd);
+		}
+	      else /* trig nothing */
+		lazycd = 2;
+	    }
+
+	  xfree (newpwd);
+	}
+
+      xfree (oldpwd);
     }

   /* We have to make the child before we check for the non-existence
@@ -3636,6 +3782,14 @@
       if (async)
 	interactive = old_interactive;

+      if (lazycd)
+	{
+	  if (lazycd_result || lazycd == 2)
+	    exit (lazycd_result);
+
+	  command = "/bin/sh";
+	}
+
       if (command == 0)
 	{
 	  internal_error (_("%s: command not found"), pathname);
@@ -3651,6 +3805,10 @@
   else
     {
 parent_return:
+
+      if (lazycd == 1 && !lazycd_result)
+	dispose_words (words);
+
       /* Make sure that the pipes are closed in the parent. */
       close_pipes (pipe_in, pipe_out);
 #if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)