1 files changed, 131 insertions, 82 deletions

diff --git a/builtins/exec.def b/builtins/exec.def
index f950afc6..c14af75f 100644
--- a/builtins/exec.def
+++ b/builtins/exec.def
@@ -23,141 +23,190 @@ $PRODUCES exec.c
 
 $BUILTIN exec
 $FUNCTION exec_builtin
-$SHORT_DOC exec [ [-] file [redirection ...]]
+$SHORT_DOC exec [-cl] [-a name] file [redirection ...]
 Exec FILE, replacing this shell with the specified program.
 If FILE is not specified, the redirections take effect in this
-shell.  If the first argument is `-', then place a dash in the
-zeroth arg passed to FILE.  If the file cannot be exec'ed and
-the shell is not interactive, then the shell exits, unless the
-shell variable "no_exit_on_failed_exec" exists.
+shell.  If the first argument is `-l', then place a dash in the
+zeroth arg passed to FILE, as login does.  If the `-c' option
+is supplied, FILE is executed with a null environment.  The `-a'
+option means to make set argv[0] of the executed process to NAME.
+If the file cannot be executed and the shell is not interactive,
+then the shell exits, unless the shell option `execfail' is set.
 $END
 
-#include "../shell.h"
+#include <config.h>
+
 #include <sys/types.h>
 #include "../posixstat.h"
 #include <signal.h>
 #include <errno.h>
 
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "../bashansi.h"
+
+#include "../shell.h"
 #include "../execute_cmd.h"
-#include "common.h"
+#if defined (JOB_CONTROL)
+#  include "../jobs.h"
+#endif
 #include "../flags.h"
+#include "../trap.h"
+#if defined (HISTORY)
+#  include "../bashhist.h"
+#endif
+#include "common.h"
+#include "bashgetopt.h"
 
 /* Not all systems declare ERRNO in errno.h... and some systems #define it! */
 #if !defined (errno)
 extern int errno;
 #endif /* !errno */
+
 extern int interactive, subshell_environment;
 extern REDIRECT *redirection_undo_list;
 
+int no_exit_on_failed_exec;
+
+/* If the user wants this to look like a login shell, then
+   prepend a `-' onto NAME and return the new name. */
+static char *
+mkdashname (name)
+     char *name;
+{
+  char *ret;
+
+  ret = xmalloc (2 + strlen (name));
+  ret[0] = '-';
+  strcpy (ret + 1, name);
+  return ret;
+}
+
 int
 exec_builtin (list)
      WORD_LIST *list;
 {
   int exit_value = EXECUTION_FAILURE;
+  int cleanenv, login, opt;
+  char *argv0, *command, **args, **env, *newname;
 
-  maybe_make_export_env ();
+  cleanenv = login = 0;
+  argv0 = (char *)NULL;
+
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "cla:")) != -1)
+    {
+      switch (opt)
+	{
+	case 'c':
+	  cleanenv = 1;
+	  break;
+	case 'l':
+	  login = 1;
+	  break;
+	case 'a':
+	  argv0 = list_optarg;
+	  break;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
 
   /* First, let the redirections remain. */
   dispose_redirects (redirection_undo_list);
   redirection_undo_list = (REDIRECT *)NULL;
 
-  if (!list)
+  if (list == 0)
     return (EXECUTION_SUCCESS);
-  else
+
+#if defined (RESTRICTED_SHELL)
+  if (restricted)
     {
-      /* Otherwise, execve the new command with args. */
-      char *command, **args;
-      int dash_name = 0;
+      builtin_error ("restricted");
+      return (EXECUTION_FAILURE);
+    }
+#endif /* RESTRICTED_SHELL */
 
-      if (list->word->word[0] == '-' && !list->word->word[1])
-	{
-	  /* The user would like to exec this command as if it was a
-	     login command.  Do so. */
-	  list = list->next;
-	  dash_name++;
-	}
+  args = word_list_to_argv (list, 1, 0, (int *)NULL);
 
-      if (!list)
-	return (EXECUTION_SUCCESS);
+  /* A command with a slash anywhere in its name is not looked up in $PATH. */
+  command = absolute_program (args[0]) ? args[0] : search_for_command (args[0]);
 
-#if defined (RESTRICTED_SHELL)
-      if (restricted)
-	{
-	  builtin_error ("restricted");
-	  return (EXECUTION_FAILURE);
-	}
-#endif /* RESTRICTED_SHELL */
+  if (command == 0)
+    {
+      builtin_error ("%s: not found", args[0]);
+      exit_value = EX_NOTFOUND;	/* As per Posix.2, 3.14.6 */
+      goto failed_exec;
+    }
 
-      args = make_word_array (list);
+  command = full_pathname (command);
 
-      /* A command with a slash anywhere in its name is not looked up in
-	 the search path. */
-      if (absolute_program (args[0]))
-	command = args[0];
-      else
-	command = find_user_command (args[0]);
-      if (!command)
-	{
-	  builtin_error ("%s: not found", args[0]);
-	  exit_value = EX_NOTFOUND;	/* As per Posix.2, 3.14.6 */
-	  goto failed_exec;
-	}
+  if (argv0)
+    {
+      free (args[0]);
+      args[0] = login ? mkdashname (argv0) : savestring (argv0);
+    }
+  else if (login)
+    {
+      newname = mkdashname (args[0]);
+      free (args[0]);
+      args[0] = newname;
+    }
 
-      command = full_pathname (command);
-      /* If the user wants this to look like a login shell, then
-	 prepend a `-' onto the first argument (argv[0]). */
-      if (dash_name)
-	{
-	  char *new_name = xmalloc (2 + strlen (args[0]));
-	  new_name[0] = '-';
-	  strcpy (new_name + 1, args[0]);
-	  free (args[0]);
-	  args[0] = new_name;
-	}
+  /* Decrement SHLVL by 1 so a new shell started here has the same value,
+     preserving the appearance.  After we do that, we need to change the
+     exported environment to include the new value. */
+  if (cleanenv == 0)
+    adjust_shell_level (-1);
 
-      /* Decrement SHLVL by 1 so a new shell started here has the same value,
-	 preserving the appearance.  After we do that, we need to change the
-	 exported environment to include the new value. */
-      adjust_shell_level (-1);
+  if (cleanenv)
+    env = (char **)NULL;
+  else
+    {	
       maybe_make_export_env ();
+      env = export_env;
+    }
 
 #if defined (HISTORY)
-      maybe_save_shell_history ();
+  maybe_save_shell_history ();
 #endif /* HISTORY */
-      restore_original_signals ();
+
+  restore_original_signals ();
 
 #if defined (JOB_CONTROL)
-      if (subshell_environment == 0)
-	end_job_control ();
+  if (subshell_environment == 0)
+    end_job_control ();
 #endif /* JOB_CONTROL */
 
-      shell_execve (command, args, export_env);
-
-      adjust_shell_level (1);
+  shell_execve (command, args, env);
+  if (cleanenv == 0)
+    adjust_shell_level (1);
 
-      if (!executable_file (command))
-	{
-	  builtin_error ("%s: cannot execute: %s", command, strerror (errno));
-	  exit_value = EX_NOEXEC;	/* As per Posix.2, 3.14.6 */
-	}
-      else
-	file_error (command);
+  if (executable_file (command) == 0)
+    {
+      builtin_error ("%s: cannot execute: %s", command, strerror (errno));
+      exit_value = EX_NOEXEC;	/* As per Posix.2, 3.14.6 */
+    }
+  else
+    file_error (command);
 
-  failed_exec:
-      if (command)
-	free (command);
+failed_exec:
+  if (command)
+    free (command);
 
-      if (subshell_environment ||
-	  (!interactive && !find_variable ("no_exit_on_failed_exec")))
-	exit (exit_value);
+  if (subshell_environment || (interactive == 0 && no_exit_on_failed_exec == 0))
+    exit_shell (exit_value);
 
-      initialize_traps ();
-      reinitialize_signals ();
+  initialize_traps ();
+  reinitialize_signals ();
 
 #if defined (JOB_CONTROL)
-      restart_job_control ();
+  restart_job_control ();
 #endif /* JOB_CONTROL */
 
-      return (exit_value);
-    }
+  return (exit_value);
 }