initial import from bash_3.1dfsg.orig.tar.gz

1 files changed, 4067 insertions, 0 deletions

diff --git a/execute_cmd.c b/execute_cmd.c
new file mode 100644
index 0000000..ce90d25
--- /dev/null
+++ b/execute_cmd.c
@@ -0,0 +1,4067 @@
+/* execute_command.c -- Execute a COMMAND structure. */
+
+/* Copyright (C) 1987-2005 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 2, 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, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
+#include "config.h"
+
+#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
+  #pragma alloca
+#endif /* _AIX && RISC6000 && !__GNUC__ */
+
+#include <stdio.h>
+#include "chartypes.h"
+#include "bashtypes.h"
+#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
+#  include <sys/file.h>
+#endif
+#include "filecntl.h"
+#include "posixstat.h"
+#include <signal.h>
+#ifndef _MINIX
+#  include <sys/param.h>
+#endif
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "posixtime.h"
+
+#if defined (HAVE_SYS_RESOURCE_H) && !defined (RLIMTYPE)
+#  include <sys/resource.h>
+#endif
+
+#if defined (HAVE_SYS_TIMES_H) && defined (HAVE_TIMES)
+#  include <sys/times.h>
+#endif
+
+#include <errno.h>
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#include "bashansi.h"
+#include "bashintl.h"
+
+#include "memalloc.h"
+#include "shell.h"
+#include <y.tab.h>	/* use <...> so we pick it up from the build directory */
+#include "flags.h"
+#include "builtins.h"
+#include "hashlib.h"
+#include "jobs.h"
+#include "execute_cmd.h"
+#include "findcmd.h"
+#include "redir.h"
+#include "trap.h"
+#include "pathexp.h"
+#include "hashcmd.h"
+
+#if defined (COND_COMMAND)
+#  include "test.h"
+#endif
+
+#include "builtins/common.h"
+#include "builtins/builtext.h"	/* list of builtins */
+
+#include <glob/strmatch.h>
+#include <tilde/tilde.h>
+
+#if defined (BUFFERED_INPUT)
+#  include "input.h"
+#endif
+
+#if defined (ALIAS)
+#  include "alias.h"
+#endif
+
+#if defined (HISTORY)
+#  include "bashhist.h"
+#endif
+
+extern int posixly_correct;
+extern int breaking, continuing, loop_level;
+extern int expand_aliases;
+extern int parse_and_execute_level, running_trap;
+extern int command_string_index, line_number;
+extern int dot_found_in_search;
+extern int already_making_children;
+extern int tempenv_assign_error;
+extern char *the_printed_command, *shell_name;
+extern pid_t last_command_subst_pid;
+extern sh_builtin_func_t *last_shell_builtin, *this_shell_builtin;
+extern char **subshell_argv, **subshell_envp;
+extern int subshell_argc;
+#if 0
+extern char *glob_argv_flags;
+#endif
+
+extern int close __P((int));
+
+/* Static functions defined and used in this file. */
+static void close_pipes __P((int, int));
+static void do_piping __P((int, int));
+static void bind_lastarg __P((char *));
+static int shell_control_structure __P((enum command_type));
+static void cleanup_redirects __P((REDIRECT *));
+
+#if defined (JOB_CONTROL)
+static int restore_signal_mask __P((sigset_t *));
+#endif
+
+static void async_redirect_stdin __P((void));
+
+static int builtin_status __P((int));
+
+static int execute_for_command __P((FOR_COM *));
+#if defined (SELECT_COMMAND)
+static int print_index_and_element __P((int, int, WORD_LIST *));
+static void indent __P((int, int));
+static void print_select_list __P((WORD_LIST *, int, int, int));
+static char *select_query __P((WORD_LIST *, int, char *, int));
+static int execute_select_command __P((SELECT_COM *));
+#endif
+#if defined (DPAREN_ARITHMETIC)
+static int execute_arith_command __P((ARITH_COM *));
+#endif
+#if defined (COND_COMMAND)
+static int execute_cond_node __P((COND_COM *));
+static int execute_cond_command __P((COND_COM *));
+#endif
+#if defined (COMMAND_TIMING)
+static int mkfmt __P((char *, int, int, time_t, int));
+static void print_formatted_time __P((FILE *, char *,
+				      time_t, int, time_t, int,
+				      time_t, int, int));
+static int time_command __P((COMMAND *, int, int, int, struct fd_bitmap *));
+#endif
+#if defined (ARITH_FOR_COMMAND)
+static intmax_t eval_arith_for_expr __P((WORD_LIST *, int *));
+static int execute_arith_for_command __P((ARITH_FOR_COM *));
+#endif
+static int execute_case_command __P((CASE_COM *));
+static int execute_while_command __P((WHILE_COM *));
+static int execute_until_command __P((WHILE_COM *));
+static int execute_while_or_until __P((WHILE_COM *, int));
+static int execute_if_command __P((IF_COM *));
+static int execute_null_command __P((REDIRECT *, int, int, int));
+static void fix_assignment_words __P((WORD_LIST *));
+static int execute_simple_command __P((SIMPLE_COM *, int, int, int, struct fd_bitmap *));
+static int execute_builtin __P((sh_builtin_func_t *, WORD_LIST *, int, int));
+static int execute_function __P((SHELL_VAR *, WORD_LIST *, int, struct fd_bitmap *, int, int));
+static int execute_builtin_or_function __P((WORD_LIST *, sh_builtin_func_t *,
+					    SHELL_VAR *,
+					    REDIRECT *, struct fd_bitmap *, int));
+static void execute_subshell_builtin_or_function __P((WORD_LIST *, REDIRECT *,
+						      sh_builtin_func_t *,
+						      SHELL_VAR *,
+						      int, int, int,
+						      struct fd_bitmap *,
+						      int));
+static void execute_disk_command __P((WORD_LIST *, REDIRECT *, char *,
+				      int, int, int, struct fd_bitmap *, int));
+
+static char *getinterp __P((char *, int, int *));
+static void initialize_subshell __P((void));
+static int execute_in_subshell __P((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_pipeline __P((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_connection __P((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_intern_function __P((WORD_DESC *, COMMAND *));
+
+/* The line number that the currently executing function starts on. */
+static int function_line_number;
+
+/* Set to 1 if fd 0 was the subject of redirection to a subshell.  Global
+   so that reader_loop can set it to zero before executing a command. */
+int stdin_redir;
+
+/* The name of the command that is currently being executed.
+   `test' needs this, for example. */
+char *this_command_name;
+
+/* The printed representation of the currently-executing command (same as
+   the_printed_command), except when a trap is being executed.  Useful for
+   a debugger to know where exactly the program is currently executing. */
+char *the_printed_command_except_trap;
+
+static COMMAND *currently_executing_command;
+
+struct stat SB;		/* used for debugging */
+
+static int special_builtin_failed;
+
+/* XXX - set to 1 if we're running the DEBUG trap and we want to show the line
+   number containing the function name.  Used by executing_line_number to
+   report the correct line number.  Kind of a hack. */
+static int showing_function_line;
+
+/* For catching RETURN in a function. */
+int return_catch_flag;
+int return_catch_value;
+procenv_t return_catch;
+
+/* The value returned by the last synchronous command. */
+int last_command_exit_value;
+
+/* Whether or not the last command (corresponding to last_command_exit_value)
+   was terminated by a signal, and, if so, which one. */
+int last_command_exit_signal;
+
+/* The list of redirections to perform which will undo the redirections
+   that I made in the shell. */
+REDIRECT *redirection_undo_list = (REDIRECT *)NULL;
+
+/* The list of redirections to perform which will undo the internal
+   redirections performed by the `exec' builtin.  These are redirections
+   that must be undone even when exec discards redirection_undo_list. */
+REDIRECT *exec_redirection_undo_list = (REDIRECT *)NULL;
+
+/* Non-zero if we have just forked and are currently running in a subshell
+   environment. */
+int subshell_environment;
+
+/* Count of nested subshells, like SHLVL.  Available via $BASH_SUBSHELL */
+int subshell_level = 0;
+
+/* Currently-executing shell function. */
+SHELL_VAR *this_shell_function;
+
+/* If non-zero, matches in case and [[ ... ]] are case-insensitive */
+int match_ignore_case = 0;
+
+struct fd_bitmap *current_fds_to_close = (struct fd_bitmap *)NULL;
+
+#define FD_BITMAP_DEFAULT_SIZE 32
+
+/* Functions to allocate and deallocate the structures used to pass
+   information from the shell to its children about file descriptors
+   to close. */
+struct fd_bitmap *
+new_fd_bitmap (size)
+     int size;
+{
+  struct fd_bitmap *ret;
+
+  ret = (struct fd_bitmap *)xmalloc (sizeof (struct fd_bitmap));
+
+  ret->size = size;
+
+  if (size)
+    {
+      ret->bitmap = (char *)xmalloc (size);
+      memset (ret->bitmap, '\0', size);
+    }
+  else
+    ret->bitmap = (char *)NULL;
+  return (ret);
+}
+
+void
+dispose_fd_bitmap (fdbp)
+     struct fd_bitmap *fdbp;
+{
+  FREE (fdbp->bitmap);
+  free (fdbp);
+}
+
+void
+close_fd_bitmap (fdbp)
+     struct fd_bitmap *fdbp;
+{
+  register int i;
+
+  if (fdbp)
+    {
+      for (i = 0; i < fdbp->size; i++)
+	if (fdbp->bitmap[i])
+	  {
+	    close (i);
+	    fdbp->bitmap[i] = 0;
+	  }
+    }
+}
+
+/* Return the line number of the currently executing command. */
+int
+executing_line_number ()
+{
+  if (executing && showing_function_line == 0 &&
+      (variable_context == 0 || interactive_shell == 0) &&
+      currently_executing_command)
+    {
+#if defined (COND_COMMAND)
+      if (currently_executing_command->type == cm_cond)
+	return currently_executing_command->value.Cond->line;
+#endif
+#if defined (DPAREN_ARITHMETIC)
+      else if (currently_executing_command->type == cm_arith)
+	return currently_executing_command->value.Arith->line;
+#endif
+#if defined (ARITH_FOR_COMMAND)
+      else if (currently_executing_command->type == cm_arith_for)
+	return currently_executing_command->value.ArithFor->line;
+#endif
+
+	return line_number;
+    }
+  else
+    return line_number;
+}
+
+/* Execute the command passed in COMMAND.  COMMAND is exactly what
+   read_command () places into GLOBAL_COMMAND.  See "command.h" for the
+   details of the command structure.
+
+   EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
+   return values.  Executing a command with nothing in it returns
+   EXECUTION_SUCCESS. */
+int
+execute_command (command)
+     COMMAND *command;
+{
+  struct fd_bitmap *bitmap;
+  int result;
+
+  current_fds_to_close = (struct fd_bitmap *)NULL;
+  bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
+  begin_unwind_frame ("execute-command");
+  add_unwind_protect (dispose_fd_bitmap, (char *)bitmap);
+
+  /* Just do the command, but not asynchronously. */
+  result = execute_command_internal (command, 0, NO_PIPE, NO_PIPE, bitmap);
+
+  dispose_fd_bitmap (bitmap);
+  discard_unwind_frame ("execute-command");
+
+#if defined (PROCESS_SUBSTITUTION)
+  /* don't unlink fifos if we're in a shell function; wait until the function
+     returns. */
+  if (variable_context == 0)
+    unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+
+  return (result);
+}
+
+/* Return 1 if TYPE is a shell control structure type. */
+static int
+shell_control_structure (type)
+     enum command_type type;
+{
+  switch (type)
+    {
+#if defined (ARITH_FOR_COMMAND)
+    case cm_arith_for:
+#endif
+#if defined (SELECT_COMMAND)
+    case cm_select:
+#endif
+#if defined (DPAREN_ARITHMETIC)
+    case cm_arith:
+#endif
+#if defined (COND_COMMAND)
+    case cm_cond:
+#endif
+    case cm_case:
+    case cm_while:
+    case cm_until:
+    case cm_if:
+    case cm_for:
+    case cm_group:
+    case cm_function_def:
+      return (1);
+
+    default:
+      return (0);
+    }
+}
+
+/* A function to use to unwind_protect the redirection undo list
+   for loops. */
+static void
+cleanup_redirects (list)
+     REDIRECT *list;
+{
+  do_redirections (list, RX_ACTIVE);
+  dispose_redirects (list);
+}
+
+#if 0
+/* Function to unwind_protect the redirections for functions and builtins. */
+static void
+cleanup_func_redirects (list)
+     REDIRECT *list;
+{
+  do_redirections (list, RX_ACTIVE);
+}
+#endif
+
+void
+dispose_exec_redirects ()
+{
+  if (exec_redirection_undo_list)
+    {
+      dispose_redirects (exec_redirection_undo_list);
+      exec_redirection_undo_list = (REDIRECT *)NULL;
+    }
+}
+
+#if defined (JOB_CONTROL)
+/* A function to restore the signal mask to its proper value when the shell
+   is interrupted or errors occur while creating a pipeline. */
+static int
+restore_signal_mask (set)
+     sigset_t *set;
+{
+  return (sigprocmask (SIG_SETMASK, set, (sigset_t *)NULL));
+}
+#endif /* JOB_CONTROL */
+
+#ifdef DEBUG
+/* A debugging function that can be called from gdb, for instance. */
+void
+open_files ()
+{
+  register int i;
+  int f, fd_table_size;
+
+  fd_table_size = getdtablesize ();
+
+  fprintf (stderr, "pid %ld open files:", (long)getpid ());
+  for (i = 3; i < fd_table_size; i++)
+    {
+      if ((f = fcntl (i, F_GETFD, 0)) != -1)
+	fprintf (stderr, " %d (%s)", i, f ? "close" : "open");
+    }
+  fprintf (stderr, "\n");
+}
+#endif
+
+static void
+async_redirect_stdin ()
+{
+  int fd;
+
+  fd = open ("/dev/null", O_RDONLY);
+  if (fd > 0)
+    {
+      dup2 (fd, 0);
+      close (fd);
+    }
+  else if (fd < 0)
+    internal_error (_("cannot redirect standard input from /dev/null: %s"), strerror (errno));
+}
+
+#define DESCRIBE_PID(pid) do { if (interactive) describe_pid (pid); } while (0)
+
+/* Execute the command passed in COMMAND, perhaps doing it asynchrounously.
+   COMMAND is exactly what read_command () places into GLOBAL_COMMAND.
+   ASYNCHROUNOUS, if non-zero, says to do this command in the background.
+   PIPE_IN and PIPE_OUT are file descriptors saying where input comes
+   from and where it goes.  They can have the value of NO_PIPE, which means
+   I/O is stdin/stdout.
+   FDS_TO_CLOSE is a list of file descriptors to close once the child has
+   been forked.  This list often contains the unusable sides of pipes, etc.
+
+   EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
+   return values.  Executing a command with nothing in it returns
+   EXECUTION_SUCCESS. */
+int
+execute_command_internal (command, asynchronous, pipe_in, pipe_out,
+			  fds_to_close)
+     COMMAND *command;
+     int asynchronous;
+     int pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  int exec_result, invert, ignore_return, was_error_trap;
+  REDIRECT *my_undo_list, *exec_undo_list;
+  volatile int last_pid;
+  volatile int save_line_number;
+
+  if (command == 0 || breaking || continuing || read_but_dont_execute)
+    return (EXECUTION_SUCCESS);
+
+  run_pending_traps ();
+
+#if 0
+  if (running_trap == 0)
+#endif
+    currently_executing_command = command;
+
+  invert = (command->flags & CMD_INVERT_RETURN) != 0;
+
+  /* If we're inverting the return value and `set -e' has been executed,
+     we don't want a failing command to inadvertently cause the shell
+     to exit. */
+  if (exit_immediately_on_error && invert)	/* XXX */
+    command->flags |= CMD_IGNORE_RETURN;	/* XXX */
+
+  exec_result = EXECUTION_SUCCESS;
+
+  /* If a command was being explicitly run in a subshell, or if it is
+     a shell control-structure, and it has a pipe, then we do the command
+     in a subshell. */
+  if (command->type == cm_subshell && (command->flags & CMD_NO_FORK))
+    return (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close));
+
+  if (command->type == cm_subshell ||
+      (command->flags & (CMD_WANT_SUBSHELL|CMD_FORCE_SUBSHELL)) ||
+      (shell_control_structure (command->type) &&
+       (pipe_out != NO_PIPE || pipe_in != NO_PIPE || asynchronous)))
+    {
+      pid_t paren_pid;
+
+      /* Fork a subshell, turn off the subshell bit, turn off job
+	 control and call execute_command () on the command again. */
+      paren_pid = make_child (savestring (make_command_string (command)),
+			      asynchronous);
+      if (paren_pid == 0)
+	exit (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close));
+	/* NOTREACHED */
+      else
+	{
+	  close_pipes (pipe_in, pipe_out);
+
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+	  unlink_fifo_list ();
+#endif
+	  /* If we are part of a pipeline, and not the end of the pipeline,
+	     then we should simply return and let the last command in the
+	     pipe be waited for.  If we are not in a pipeline, or are the
+	     last command in the pipeline, then we wait for the subshell
+	     and return its exit status as usual. */
+	  if (pipe_out != NO_PIPE)
+	    return (EXECUTION_SUCCESS);
+
+	  stop_pipeline (asynchronous, (COMMAND *)NULL);
+
+	  if (asynchronous == 0)
+	    {
+	      last_command_exit_value = wait_for (paren_pid);
+
+	      /* If we have to, invert the return value. */
+	      if (invert)
+		exec_result = ((last_command_exit_value == EXECUTION_SUCCESS)
+				? EXECUTION_FAILURE
+				: EXECUTION_SUCCESS);
+	      else
+		exec_result = last_command_exit_value;
+
+	      return (last_command_exit_value = exec_result);
+	    }
+	  else
+	    {
+	      DESCRIBE_PID (paren_pid);
+
+	      run_pending_traps ();
+
+	      return (EXECUTION_SUCCESS);
+	    }
+	}
+    }
+
+#if defined (COMMAND_TIMING)
+  if (command->flags & CMD_TIME_PIPELINE)
+    {
+      if (asynchronous)
+	{
+	  command->flags |= CMD_FORCE_SUBSHELL;
+	  exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
+	}
+      else
+	{
+	  exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+#if 0
+	  if (running_trap == 0)
+#endif
+	    currently_executing_command = (COMMAND *)NULL;
+	}
+      return (exec_result);
+    }
+#endif /* COMMAND_TIMING */
+
+  if (shell_control_structure (command->type) && command->redirects)
+    stdin_redir = stdin_redirects (command->redirects);
+
+  /* Handle WHILE FOR CASE etc. with redirections.  (Also '&' input
+     redirection.)  */
+  if (do_redirections (command->redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+    {
+      cleanup_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+      dispose_exec_redirects ();
+      return (EXECUTION_FAILURE);
+    }
+
+  if (redirection_undo_list)
+    {
+      my_undo_list = (REDIRECT *)copy_redirects (redirection_undo_list);
+      dispose_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+    }
+  else
+    my_undo_list = (REDIRECT *)NULL;
+
+  if (exec_redirection_undo_list)
+    {
+      exec_undo_list = (REDIRECT *)copy_redirects (exec_redirection_undo_list);
+      dispose_redirects (exec_redirection_undo_list);
+      exec_redirection_undo_list = (REDIRECT *)NULL;
+    }
+  else
+    exec_undo_list = (REDIRECT *)NULL;
+
+  if (my_undo_list || exec_undo_list)
+    begin_unwind_frame ("loop_redirections");
+
+  if (my_undo_list)
+    add_unwind_protect ((Function *)cleanup_redirects, my_undo_list);
+
+  if (exec_undo_list)
+    add_unwind_protect ((Function *)dispose_redirects, exec_undo_list);
+
+  ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+  QUIT;
+
+  switch (command->type)
+    {
+    case cm_simple:
+      {
+	save_line_number = line_number;
+	/* We can't rely on variables retaining their values across a
+	   call to execute_simple_command if a longjmp occurs as the
+	   result of a `return' builtin.  This is true for sure with gcc. */
+#if defined (RECYCLES_PIDS)
+	last_made_pid = NO_PID;
+#endif
+	last_pid = last_made_pid;
+	was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+
+	if (ignore_return && command->value.Simple)
+	  command->value.Simple->flags |= CMD_IGNORE_RETURN;
+	if (command->flags & CMD_STDIN_REDIR)
+	  command->value.Simple->flags |= CMD_STDIN_REDIR;
+
+	line_number = command->value.Simple->line;
+	exec_result =
+	  execute_simple_command (command->value.Simple, pipe_in, pipe_out,
+				  asynchronous, fds_to_close);
+	line_number = save_line_number;
+
+	/* The temporary environment should be used for only the simple
+	   command immediately following its definition. */
+	dispose_used_env_vars ();
+
+#if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA)
+	/* Reclaim memory allocated with alloca () on machines which
+	   may be using the alloca emulation code. */
+	(void) alloca (0);
+#endif /* (ultrix && mips) || C_ALLOCA */
+
+	/* If we forked to do the command, then we must wait_for ()
+	   the child. */
+
+	/* XXX - this is something to watch out for if there are problems
+	   when the shell is compiled without job control. */
+	if (already_making_children && pipe_out == NO_PIPE &&
+	    last_made_pid != last_pid)
+	  {
+	    stop_pipeline (asynchronous, (COMMAND *)NULL);
+
+	    if (asynchronous)
+	      {
+		DESCRIBE_PID (last_made_pid);
+	      }
+	    else
+#if !defined (JOB_CONTROL)
+	      /* Do not wait for asynchronous processes started from
+		 startup files. */
+	    if (last_made_pid != last_asynchronous_pid)
+#endif
+	    /* When executing a shell function that executes other
+	       commands, this causes the last simple command in
+	       the function to be waited for twice.  This also causes
+	       subshells forked to execute builtin commands (e.g., in
+	       pipelines) to be waited for twice. */
+	      exec_result = wait_for (last_made_pid);
+	  }
+      }
+
+      if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  run_error_trap ();
+	}
+
+      if (ignore_return == 0 && invert == 0 &&
+	  ((posixly_correct && interactive == 0 && special_builtin_failed) ||
+	   (exit_immediately_on_error && (exec_result != EXECUTION_SUCCESS))))
+	{
+	  last_command_exit_value = exec_result;
+	  run_pending_traps ();
+	  jump_to_top_level (ERREXIT);
+	}
+
+      break;
+
+    case cm_for:
+      if (ignore_return)
+	command->value.For->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_for_command (command->value.For);
+      break;
+
+#if defined (ARITH_FOR_COMMAND)
+    case cm_arith_for:
+      if (ignore_return)
+	command->value.ArithFor->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_arith_for_command (command->value.ArithFor);
+      break;
+#endif
+
+#if defined (SELECT_COMMAND)
+    case cm_select:
+      if (ignore_return)
+	command->value.Select->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_select_command (command->value.Select);
+      break;
+#endif
+
+    case cm_case:
+      if (ignore_return)
+	command->value.Case->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_case_command (command->value.Case);
+      break;
+
+    case cm_while:
+      if (ignore_return)
+	command->value.While->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_while_command (command->value.While);
+      break;
+
+    case cm_until:
+      if (ignore_return)
+	command->value.While->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_until_command (command->value.While);
+      break;
+
+    case cm_if:
+      if (ignore_return)
+	command->value.If->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_if_command (command->value.If);
+      break;
+
+    case cm_group:
+
+      /* This code can be executed from either of two paths: an explicit
+	 '{}' command, or via a function call.  If we are executed via a
+	 function call, we have already taken care of the function being
+	 executed in the background (down there in execute_simple_command ()),
+	 and this command should *not* be marked as asynchronous.  If we
+	 are executing a regular '{}' group command, and asynchronous == 1,
+	 we must want to execute the whole command in the background, so we
+	 need a subshell, and we want the stuff executed in that subshell
+	 (this group command) to be executed in the foreground of that
+	 subshell (i.e. there will not be *another* subshell forked).
+
+	 What we do is to force a subshell if asynchronous, and then call
+	 execute_command_internal again with asynchronous still set to 1,
+	 but with the original group command, so the printed command will
+	 look right.
+
+	 The code above that handles forking off subshells will note that
+	 both subshell and async are on, and turn off async in the child
+	 after forking the subshell (but leave async set in the parent, so
+	 the normal call to describe_pid is made).  This turning off
+	 async is *crucial*; if it is not done, this will fall into an
+	 infinite loop of executions through this spot in subshell after
+	 subshell until the process limit is exhausted. */
+
+      if (asynchronous)
+	{
+	  command->flags |= CMD_FORCE_SUBSHELL;
+	  exec_result =
+	    execute_command_internal (command, 1, pipe_in, pipe_out,
+				      fds_to_close);
+	}
+      else
+	{
+	  if (ignore_return && command->value.Group->command)
+	    command->value.Group->command->flags |= CMD_IGNORE_RETURN;
+	  exec_result =
+	    execute_command_internal (command->value.Group->command,
+				      asynchronous, pipe_in, pipe_out,
+				      fds_to_close);
+	}
+      break;
+
+    case cm_connection:
+      exec_result = execute_connection (command, asynchronous,
+					pipe_in, pipe_out, fds_to_close);
+      break;
+
+#if defined (DPAREN_ARITHMETIC)
+    case cm_arith:
+      if (ignore_return)
+	command->value.Arith->flags |= CMD_IGNORE_RETURN;
+      exec_result = execute_arith_command (command->value.Arith);
+      break;
+#endif
+
+#if defined (COND_COMMAND)
+    case cm_cond:
+      if (ignore_return)
+	command->value.Cond->flags |= CMD_IGNORE_RETURN;
+      save_line_number = line_number;
+      exec_result = execute_cond_command (command->value.Cond);
+      line_number = save_line_number;
+      break;
+#endif
+    
+    case cm_function_def:
+      exec_result = execute_intern_function (command->value.Function_def->name,
+					     command->value.Function_def->command);
+      break;
+
+    default:
+      command_error ("execute_command", CMDERR_BADTYPE, command->type, 0);
+    }
+
+  if (my_undo_list)
+    {
+      do_redirections (my_undo_list, RX_ACTIVE);
+      dispose_redirects (my_undo_list);
+    }
+
+  if (exec_undo_list)
+    dispose_redirects (exec_undo_list);
+
+  if (my_undo_list || exec_undo_list)
+    discard_unwind_frame ("loop_redirections");
+
+  /* Invert the return value if we have to */
+  if (invert)
+    exec_result = (exec_result == EXECUTION_SUCCESS)
+		    ? EXECUTION_FAILURE
+		    : EXECUTION_SUCCESS;
+
+  last_command_exit_value = exec_result;
+  run_pending_traps ();
+#if 0
+  if (running_trap == 0)
+#endif
+    currently_executing_command = (COMMAND *)NULL;
+  return (last_command_exit_value);
+}
+
+#if defined (COMMAND_TIMING)
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+extern struct timeval *difftimeval __P((struct timeval *, struct timeval *, struct timeval *));
+extern struct timeval *addtimeval __P((struct timeval *, struct timeval *, struct timeval *));
+extern int timeval_to_cpu __P((struct timeval *, struct timeval *, struct timeval *));
+#endif
+
+#define POSIX_TIMEFORMAT "real %2R\nuser %2U\nsys %2S"
+#define BASH_TIMEFORMAT  "\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS"
+
+static int precs[] = { 0, 100, 10, 1 };
+
+/* Expand one `%'-prefixed escape sequence from a time format string. */
+static int
+mkfmt (buf, prec, lng, sec, sec_fraction)
+     char *buf;
+     int prec, lng;
+     time_t sec;
+     int sec_fraction;
+{
+  time_t min;
+  char abuf[INT_STRLEN_BOUND(time_t) + 1];
+  int ind, aind;
+
+  ind = 0;
+  abuf[sizeof(abuf) - 1] = '\0';
+
+  /* If LNG is non-zero, we want to decompose SEC into minutes and seconds. */
+  if (lng)
+    {
+      min = sec / 60;
+      sec %= 60;
+      aind = sizeof(abuf) - 2;
+      do
+	abuf[aind--] = (min % 10) + '0';
+      while (min /= 10);
+      aind++;
+      while (abuf[aind])
+	buf[ind++] = abuf[aind++];
+      buf[ind++] = 'm';
+    }
+
+  /* Now add the seconds. */
+  aind = sizeof (abuf) - 2;
+  do
+    abuf[aind--] = (sec % 10) + '0';
+  while (sec /= 10);
+  aind++;
+  while (abuf[aind])
+    buf[ind++] = abuf[aind++];
+
+  /* We want to add a decimal point and PREC places after it if PREC is
+     nonzero.  PREC is not greater than 3.  SEC_FRACTION is between 0
+     and 999. */
+  if (prec != 0)
+    {
+      buf[ind++] = '.';
+      for (aind = 1; aind <= prec; aind++)
+	{
+	  buf[ind++] = (sec_fraction / precs[aind]) + '0';
+	  sec_fraction %= precs[aind];
+	}
+    }
+
+  if (lng)
+    buf[ind++] = 's';
+  buf[ind] = '\0';
+
+  return (ind);
+}
+
+/* Interpret the format string FORMAT, interpolating the following escape
+   sequences:
+		%[prec][l][RUS]
+
+   where the optional `prec' is a precision, meaning the number of
+   characters after the decimal point, the optional `l' means to format
+   using minutes and seconds (MMmNN[.FF]s), like the `times' builtin',
+   and the last character is one of
+   
+		R	number of seconds of `real' time
+		U	number of seconds of `user' time
+		S	number of seconds of `system' time
+
+   An occurrence of `%%' in the format string is translated to a `%'.  The
+   result is printed to FP, a pointer to a FILE.  The other variables are
+   the seconds and thousandths of a second of real, user, and system time,
+   resectively. */
+static void
+print_formatted_time (fp, format, rs, rsf, us, usf, ss, ssf, cpu)
+     FILE *fp;
+     char *format;
+     time_t rs;
+     int rsf;
+     time_t us;
+     int usf;
+     time_t ss;
+     int ssf, cpu;
+{
+  int prec, lng, len;
+  char *str, *s, ts[INT_STRLEN_BOUND (time_t) + sizeof ("mSS.FFFF")];
+  time_t sum;
+  int sum_frac;
+  int sindex, ssize;
+
+  len = strlen (format);
+  ssize = (len + 64) - (len % 64);
+  str = (char *)xmalloc (ssize);
+  sindex = 0;
+
+  for (s = format; *s; s++)
+    {
+      if (*s != '%' || s[1] == '\0')
+	{
+	  RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
+	  str[sindex++] = *s;
+	}
+      else if (s[1] == '%')
+	{
+	  s++;
+	  RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
+	  str[sindex++] = *s;
+	}
+      else if (s[1] == 'P')
+	{
+	  s++;
+	  if (cpu > 10000)
+	    cpu = 10000;
+	  sum = cpu / 100;
+	  sum_frac = (cpu % 100) * 10;
+	  len = mkfmt (ts, 2, 0, sum, sum_frac);
+	  RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
+	  strcpy (str + sindex, ts);
+	  sindex += len;
+	}
+      else
+	{
+	  prec = 3;	/* default is three places past the decimal point. */
+	  lng = 0;	/* default is to not use minutes or append `s' */
+	  s++;
+	  if (DIGIT (*s))		/* `precision' */
+	    {
+	      prec = *s++ - '0';
+	      if (prec > 3) prec = 3;
+	    }
+	  if (*s == 'l')		/* `length extender' */
+	    {
+	      lng = 1;
+	      s++;
+	    }
+	  if (*s == 'R' || *s == 'E')
+	    len = mkfmt (ts, prec, lng, rs, rsf);
+	  else if (*s == 'U')
+	    len = mkfmt (ts, prec, lng, us, usf);
+	  else if (*s == 'S')
+	    len = mkfmt (ts, prec, lng, ss, ssf);
+	  else
+	    {
+	      internal_error (_("TIMEFORMAT: `%c': invalid format character"), *s);
+	      free (str);
+	      return;
+	    }
+	  RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
+	  strcpy (str + sindex, ts);
+	  sindex += len;
+	}
+    }
+
+  str[sindex] = '\0';
+  fprintf (fp, "%s\n", str);
+  fflush (fp);
+
+  free (str);
+}
+
+static int
+time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+     COMMAND *command;
+     int asynchronous, pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  int rv, posix_time, old_flags;
+  time_t rs, us, ss;
+  int rsf, usf, ssf;
+  int cpu;
+  char *time_format;
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+  struct timeval real, user, sys;
+  struct timeval before, after;
+#  if defined (HAVE_STRUCT_TIMEZONE)
+  struct timezone dtz;				/* posix doesn't define this */
+#  endif
+  struct rusage selfb, selfa, kidsb, kidsa;	/* a = after, b = before */
+#else
+#  if defined (HAVE_TIMES)
+  clock_t tbefore, tafter, real, user, sys;
+  struct tms before, after;
+#  endif
+#endif
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+#  if defined (HAVE_STRUCT_TIMEZONE)
+  gettimeofday (&before, &dtz);
+#  else
+  gettimeofday (&before, (void *)NULL);
+#  endif /* !HAVE_STRUCT_TIMEZONE */
+  getrusage (RUSAGE_SELF, &selfb);
+  getrusage (RUSAGE_CHILDREN, &kidsb);
+#else
+#  if defined (HAVE_TIMES)
+  tbefore = times (&before);
+#  endif
+#endif
+
+  posix_time = (command->flags & CMD_TIME_POSIX);
+
+  old_flags = command->flags;
+  command->flags &= ~(CMD_TIME_PIPELINE|CMD_TIME_POSIX);
+  rv = execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+  command->flags = old_flags;
+
+  rs = us = ss = 0;
+  rsf = usf = ssf = cpu = 0;
+
+#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
+#  if defined (HAVE_STRUCT_TIMEZONE)
+  gettimeofday (&after, &dtz);
+#  else
+  gettimeofday (&after, (void *)NULL);
+#  endif /* !HAVE_STRUCT_TIMEZONE */
+  getrusage (RUSAGE_SELF, &selfa);
+  getrusage (RUSAGE_CHILDREN, &kidsa);
+
+  difftimeval (&real, &before, &after);
+  timeval_to_secs (&real, &rs, &rsf);
+
+  addtimeval (&user, difftimeval(&after, &selfb.ru_utime, &selfa.ru_utime),
+		     difftimeval(&before, &kidsb.ru_utime, &kidsa.ru_utime));
+  timeval_to_secs (&user, &us, &usf);
+
+  addtimeval (&sys, difftimeval(&after, &selfb.ru_stime, &selfa.ru_stime),
+		    difftimeval(&before, &kidsb.ru_stime, &kidsa.ru_stime));
+  timeval_to_secs (&sys, &ss, &ssf);
+
+  cpu = timeval_to_cpu (&real, &user, &sys);
+#else
+#  if defined (HAVE_TIMES)
+  tafter = times (&after);
+
+  real = tafter - tbefore;
+  clock_t_to_secs (real, &rs, &rsf);
+
+  user = (after.tms_utime - before.tms_utime) + (after.tms_cutime - before.tms_cutime);
+  clock_t_to_secs (user, &us, &usf);
+
+  sys = (after.tms_stime - before.tms_stime) + (after.tms_cstime - before.tms_cstime);
+  clock_t_to_secs (sys, &ss, &ssf);
+
+  cpu = (real == 0) ? 0 : ((user + sys) * 10000) / real;
+
+#  else
+  rs = us = ss = 0;
+  rsf = usf = ssf = cpu = 0;
+#  endif
+#endif
+
+  if (posix_time)
+    time_format = POSIX_TIMEFORMAT;
+  else if ((time_format = get_string_value ("TIMEFORMAT")) == 0)
+    time_format = BASH_TIMEFORMAT;
+
+  if (time_format && *time_format)
+    print_formatted_time (stderr, time_format, rs, rsf, us, usf, ss, ssf, cpu);
+
+  return rv;
+}
+#endif /* COMMAND_TIMING */
+
+/* Execute a command that's supposed to be in a subshell.  This must be
+   called after make_child and we must be running in the child process.
+   The caller will return or exit() immediately with the value this returns. */
+static int
+execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+     COMMAND *command;
+     int asynchronous;
+     int pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  int user_subshell, return_code, function_value, should_redir_stdin, invert;
+  int ois;
+  COMMAND *tcom;
+
+  USE_VAR(user_subshell);
+  USE_VAR(invert);
+  USE_VAR(tcom);
+  USE_VAR(asynchronous);
+
+  subshell_level++;
+  should_redir_stdin = (asynchronous && (command->flags & CMD_STDIN_REDIR) &&
+			  pipe_in == NO_PIPE &&
+			  stdin_redirects (command->redirects) == 0);
+
+  invert = (command->flags & CMD_INVERT_RETURN) != 0;
+  user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
+
+  command->flags &= ~(CMD_FORCE_SUBSHELL | CMD_WANT_SUBSHELL | CMD_INVERT_RETURN);
+
+  /* If a command is asynchronous in a subshell (like ( foo ) & or
+     the special case of an asynchronous GROUP command where the
+     the subshell bit is turned on down in case cm_group: below),
+     turn off `asynchronous', so that two subshells aren't spawned.
+
+     This seems semantically correct to me.  For example,
+     ( foo ) & seems to say ``do the command `foo' in a subshell
+     environment, but don't wait for that subshell to finish'',
+     and "{ foo ; bar ; } &" seems to me to be like functions or
+     builtins in the background, which executed in a subshell
+     environment.  I just don't see the need to fork two subshells. */
+
+  /* Don't fork again, we are already in a subshell.  A `doubly
+     async' shell is not interactive, however. */
+  if (asynchronous)
+    {
+#if defined (JOB_CONTROL)
+      /* If a construct like ( exec xxx yyy ) & is given while job
+	 control is active, we want to prevent exec from putting the
+	 subshell back into the original process group, carefully
+	 undoing all the work we just did in make_child. */
+      original_pgrp = -1;
+#endif /* JOB_CONTROL */
+      ois = interactive_shell;
+      interactive_shell = 0;
+      /* This test is to prevent alias expansion by interactive shells that
+	 run `(command) &' but to allow scripts that have enabled alias
+	 expansion with `shopt -s expand_alias' to continue to expand
+	 aliases. */
+      if (ois != interactive_shell)
+	expand_aliases = 0;
+      asynchronous = 0;
+    }
+
+  /* Subshells are neither login nor interactive. */
+  login_shell = interactive = 0;
+
+  subshell_environment = user_subshell ? SUBSHELL_PAREN : SUBSHELL_ASYNC;
+
+  reset_terminating_signals ();		/* in sig.c */
+  /* Cancel traps, in trap.c. */
+  restore_original_signals ();
+  if (asynchronous)
+    setup_async_signals ();
+
+#if defined (JOB_CONTROL)
+  set_sigchld_handler ();
+#endif /* JOB_CONTROL */
+
+  set_sigint_handler ();
+
+#if defined (JOB_CONTROL)
+  /* Delete all traces that there were any jobs running.  This is
+     only for subshells. */
+  without_job_control ();
+#endif /* JOB_CONTROL */
+
+  if (fds_to_close)
+    close_fd_bitmap (fds_to_close);
+
+  do_piping (pipe_in, pipe_out);
+
+  /* If this is a user subshell, set a flag if stdin was redirected.
+     This is used later to decide whether to redirect fd 0 to
+     /dev/null for async commands in the subshell.  This adds more
+     sh compatibility, but I'm not sure it's the right thing to do. */
+  if (user_subshell)
+    {
+      stdin_redir = stdin_redirects (command->redirects);
+      restore_default_signal (0);
+    }
+
+  /* If this is an asynchronous command (command &), we want to
+     redirect the standard input from /dev/null in the absence of
+     any specific redirection involving stdin. */
+  if (should_redir_stdin && stdin_redir == 0)
+    async_redirect_stdin ();
+
+  /* Do redirections, then dispose of them before recursive call. */
+  if (command->redirects)
+    {
+      if (do_redirections (command->redirects, RX_ACTIVE) != 0)
+	exit (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+
+      dispose_redirects (command->redirects);
+      command->redirects = (REDIRECT *)NULL;
+    }
+
+  tcom = (command->type == cm_subshell) ? command->value.Subshell->command : command;
+
+  if (command->flags & CMD_TIME_PIPELINE)
+    tcom->flags |= CMD_TIME_PIPELINE;
+  if (command->flags & CMD_TIME_POSIX)
+    tcom->flags |= CMD_TIME_POSIX;
+  
+  /* Make sure the subshell inherits any CMD_IGNORE_RETURN flag. */
+  if ((command->flags & CMD_IGNORE_RETURN) && tcom != command)
+    tcom->flags |= CMD_IGNORE_RETURN;
+
+  /* If this is a simple command, tell execute_disk_command that it
+     might be able to get away without forking and simply exec.
+     This means things like ( sleep 10 ) will only cause one fork.
+     If we're timing the command or inverting its return value, however,
+     we cannot do this optimization. */
+  if (user_subshell && (tcom->type == cm_simple || tcom->type == cm_subshell) &&
+      ((tcom->flags & CMD_TIME_PIPELINE) == 0) &&
+      ((tcom->flags & CMD_INVERT_RETURN) == 0))
+    {
+      tcom->flags |= CMD_NO_FORK;
+      if (tcom->type == cm_simple)
+	tcom->value.Simple->flags |= CMD_NO_FORK;
+    }
+
+  invert = (tcom->flags & CMD_INVERT_RETURN) != 0;
+  tcom->flags &= ~CMD_INVERT_RETURN;
+
+  /* If we're inside a function while executing this subshell, we
+     need to handle a possible `return'. */
+  function_value = 0;
+  if (return_catch_flag)
+    function_value = setjmp (return_catch);
+
+  if (function_value)
+    return_code = return_catch_value;
+  else
+    return_code = execute_command_internal
+      (tcom, asynchronous, NO_PIPE, NO_PIPE, fds_to_close);
+
+  /* If we are asked to, invert the return value. */
+  if (invert)
+    return_code = (return_code == EXECUTION_SUCCESS) ? EXECUTION_FAILURE
+						     : EXECUTION_SUCCESS;
+
+  /* If we were explicitly placed in a subshell with (), we need
+     to do the `shell cleanup' things, such as running traps[0]. */
+  if (user_subshell && signal_is_trapped (0))
+    {
+      last_command_exit_value = return_code;
+      return_code = run_exit_trap ();
+    }
+
+  subshell_level--;
+  return (return_code);
+  /* NOTREACHED */
+}
+
+static int
+execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+     COMMAND *command;
+     int asynchronous, pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  int prev, fildes[2], new_bitmap_size, dummyfd, ignore_return, exec_result;
+  COMMAND *cmd;
+  struct fd_bitmap *fd_bitmap;
+
+#if defined (JOB_CONTROL)
+  sigset_t set, oset;
+  BLOCK_CHILD (set, oset);
+#endif /* JOB_CONTROL */
+
+  ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+  prev = pipe_in;
+  cmd = command;
+
+  while (cmd && cmd->type == cm_connection &&
+	 cmd->value.Connection && cmd->value.Connection->connector == '|')
+    {
+      /* Make a pipeline between the two commands. */
+      if (pipe (fildes) < 0)
+	{
+	  sys_error ("pipe error");
+#if defined (JOB_CONTROL)
+	  terminate_current_pipeline ();
+	  kill_current_pipeline ();
+	  UNBLOCK_CHILD (oset);
+#endif /* JOB_CONTROL */
+	  last_command_exit_value = EXECUTION_FAILURE;
+	  /* The unwind-protects installed below will take care
+	     of closing all of the open file descriptors. */
+	  throw_to_top_level ();
+	  return (EXECUTION_FAILURE);	/* XXX */
+	}
+
+      /* Here is a problem: with the new file close-on-exec
+	 code, the read end of the pipe (fildes[0]) stays open
+	 in the first process, so that process will never get a
+	 SIGPIPE.  There is no way to signal the first process
+	 that it should close fildes[0] after forking, so it
+	 remains open.  No SIGPIPE is ever sent because there
+	 is still a file descriptor open for reading connected
+	 to the pipe.  We take care of that here.  This passes
+	 around a bitmap of file descriptors that must be
+	 closed after making a child process in execute_simple_command. */
+
+      /* We need fd_bitmap to be at least as big as fildes[0].
+	 If fildes[0] is less than fds_to_close->size, then
+	 use fds_to_close->size. */
+      new_bitmap_size = (fildes[0] < fds_to_close->size)
+				? fds_to_close->size
+				: fildes[0] + 8;
+
+      fd_bitmap = new_fd_bitmap (new_bitmap_size);
+
+      /* Now copy the old information into the new bitmap. */
+      xbcopy ((char *)fds_to_close->bitmap, (char *)fd_bitmap->bitmap, fds_to_close->size);
+
+      /* And mark the pipe file descriptors to be closed. */
+      fd_bitmap->bitmap[fildes[0]] = 1;
+
+      /* In case there are pipe or out-of-processes errors, we
+	 want all these file descriptors to be closed when
+	 unwind-protects are run, and the storage used for the
+	 bitmaps freed up. */
+      begin_unwind_frame ("pipe-file-descriptors");
+      add_unwind_protect (dispose_fd_bitmap, fd_bitmap);
+      add_unwind_protect (close_fd_bitmap, fd_bitmap);
+      if (prev >= 0)
+	add_unwind_protect (close, prev);
+      dummyfd = fildes[1];
+      add_unwind_protect (close, dummyfd);
+
+#if defined (JOB_CONTROL)
+      add_unwind_protect (restore_signal_mask, &oset);
+#endif /* JOB_CONTROL */
+
+      if (ignore_return && cmd->value.Connection->first)
+	cmd->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+      execute_command_internal (cmd->value.Connection->first, asynchronous,
+				prev, fildes[1], fd_bitmap);
+
+      if (prev >= 0)
+	close (prev);
+
+      prev = fildes[0];
+      close (fildes[1]);
+
+      dispose_fd_bitmap (fd_bitmap);
+      discard_unwind_frame ("pipe-file-descriptors");
+
+      cmd = cmd->value.Connection->second;
+    }
+
+  /* Now execute the rightmost command in the pipeline.  */
+  if (ignore_return && cmd)
+    cmd->flags |= CMD_IGNORE_RETURN;
+  exec_result = execute_command_internal (cmd, asynchronous, prev, pipe_out, fds_to_close);
+
+  if (prev >= 0)
+    close (prev);
+
+#if defined (JOB_CONTROL)
+  UNBLOCK_CHILD (oset);
+#endif
+
+  return (exec_result);
+}
+
+static int
+execute_connection (command, asynchronous, pipe_in, pipe_out, fds_to_close)
+     COMMAND *command;
+     int asynchronous, pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  REDIRECT *rp;
+  COMMAND *tc, *second;
+  int ignore_return, exec_result;
+
+  ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+  switch (command->value.Connection->connector)
+    {
+    /* Do the first command asynchronously. */
+    case '&':
+      tc = command->value.Connection->first;
+      if (tc == 0)
+	return (EXECUTION_SUCCESS);
+
+      rp = tc->redirects;
+
+      if (ignore_return)
+	tc->flags |= CMD_IGNORE_RETURN;
+      tc->flags |= CMD_AMPERSAND;
+
+      /* If this shell was compiled without job control support,
+	 if we are currently in a subshell via `( xxx )', or if job
+	 control is not active then the standard input for an
+	 asynchronous command is forced to /dev/null. */
+#if defined (JOB_CONTROL)
+      if ((subshell_environment || !job_control) && !stdin_redir)
+#else
+      if (!stdin_redir)
+#endif /* JOB_CONTROL */
+	tc->flags |= CMD_STDIN_REDIR;
+
+      exec_result = execute_command_internal (tc, 1, pipe_in, pipe_out, fds_to_close);
+
+      if (tc->flags & CMD_STDIN_REDIR)
+	tc->flags &= ~CMD_STDIN_REDIR;
+
+      second = command->value.Connection->second;
+      if (second)
+	{
+	  if (ignore_return)
+	    second->flags |= CMD_IGNORE_RETURN;
+
+	  exec_result = execute_command_internal (second, asynchronous, pipe_in, pipe_out, fds_to_close);
+	}
+
+      break;
+
+    /* Just call execute command on both sides. */
+    case ';':
+      if (ignore_return)
+	{
+	  if (command->value.Connection->first)
+	    command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+	  if (command->value.Connection->second)
+	    command->value.Connection->second->flags |= CMD_IGNORE_RETURN;
+	}
+      QUIT;
+      execute_command (command->value.Connection->first);
+      QUIT;
+      exec_result = execute_command_internal (command->value.Connection->second,
+				      asynchronous, pipe_in, pipe_out,
+				      fds_to_close);
+      break;
+
+    case '|':
+      exec_result = execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+      break;
+
+    case AND_AND:
+    case OR_OR:
+      if (asynchronous)
+	{
+	  /* If we have something like `a && b &' or `a || b &', run the
+	     && or || stuff in a subshell.  Force a subshell and just call
+	     execute_command_internal again.  Leave asynchronous on
+	     so that we get a report from the parent shell about the
+	     background job. */
+	  command->flags |= CMD_FORCE_SUBSHELL;
+	  exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
+	  break;
+	}
+
+      /* Execute the first command.  If the result of that is successful
+	 and the connector is AND_AND, or the result is not successful
+	 and the connector is OR_OR, then execute the second command,
+	 otherwise return. */
+
+      if (command->value.Connection->first)
+	command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+
+      exec_result = execute_command (command->value.Connection->first);
+      QUIT;
+      if (((command->value.Connection->connector == AND_AND) &&
+	   (exec_result == EXECUTION_SUCCESS)) ||
+	  ((command->value.Connection->connector == OR_OR) &&
+	   (exec_result != EXECUTION_SUCCESS)))
+	{
+	  if (ignore_return && command->value.Connection->second)
+	    command->value.Connection->second->flags |= CMD_IGNORE_RETURN;
+
+	  exec_result = execute_command (command->value.Connection->second);
+	}
+      break;
+
+    default:
+      command_error ("execute_connection", CMDERR_BADCONN, command->value.Connection->connector, 0);
+      jump_to_top_level (DISCARD);
+      exec_result = EXECUTION_FAILURE;
+    }
+
+  return exec_result;
+}
+
+#define REAP() \
+  do \
+    { \
+      if (!interactive_shell) \
+	reap_dead_jobs (); \
+    } \
+  while (0)
+
+/* Execute a FOR command.  The syntax is: FOR word_desc IN word_list;
+   DO command; DONE */
+static int
+execute_for_command (for_command)
+     FOR_COM *for_command;
+{
+  register WORD_LIST *releaser, *list;
+  SHELL_VAR *v;
+  char *identifier;
+  int retval, save_line_number;
+#if 0
+  SHELL_VAR *old_value = (SHELL_VAR *)NULL; /* Remember the old value of x. */
+#endif
+
+  save_line_number = line_number;
+  if (check_identifier (for_command->name, 1) == 0)
+    {
+      if (posixly_correct && interactive_shell == 0)
+	{
+	  last_command_exit_value = EX_USAGE;
+	  jump_to_top_level (ERREXIT);
+	}
+      return (EXECUTION_FAILURE);
+    }
+
+  loop_level++;
+  identifier = for_command->name->word;
+
+  list = releaser = expand_words_no_vars (for_command->map_list);
+
+  begin_unwind_frame ("for");
+  add_unwind_protect (dispose_words, releaser);
+
+#if 0
+  if (lexical_scoping)
+    {
+      old_value = copy_variable (find_variable (identifier));
+      if (old_value)
+	add_unwind_protect (dispose_variable, old_value);
+    }
+#endif
+
+  if (for_command->flags & CMD_IGNORE_RETURN)
+    for_command->action->flags |= CMD_IGNORE_RETURN;
+
+  for (retval = EXECUTION_SUCCESS; list; list = list->next)
+    {
+      QUIT;
+
+      line_number = for_command->line;
+
+      /* Remember what this command looks like, for debugger. */
+      command_string_index = 0;
+      print_for_command_head (for_command);
+
+      if (echo_command_at_execute)
+	xtrace_print_for_command_head (for_command);
+
+      /* Save this command unless it's a trap command and we're not running
+	 a debug trap. */
+      if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+	{
+	  FREE (the_printed_command_except_trap);
+	  the_printed_command_except_trap = savestring (the_printed_command);
+	}
+
+      retval = run_debug_trap ();
+#if defined (DEBUGGER)
+      /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+	 skip the command. */
+      if (debugging_mode && retval != EXECUTION_SUCCESS)
+        continue;
+#endif
+
+      this_command_name = (char *)NULL;
+      v = bind_variable (identifier, list->word->word, 0);
+      if (readonly_p (v) || noassign_p (v))
+	{
+	  line_number = save_line_number;
+	  if (readonly_p (v) && interactive_shell == 0 && posixly_correct)
+	    {
+	      last_command_exit_value = EXECUTION_FAILURE;
+	      jump_to_top_level (FORCE_EOF);
+	    }
+	  else
+	    {
+	      dispose_words (releaser);
+	      discard_unwind_frame ("for");
+	      loop_level--;
+	      return (EXECUTION_FAILURE);
+	    }
+	}
+      retval = execute_command (for_command->action);
+      REAP ();
+      QUIT;
+
+      if (breaking)
+	{
+	  breaking--;
+	  break;
+	}
+
+      if (continuing)
+	{
+	  continuing--;
+	  if (continuing)
+	    break;
+	}
+    }
+
+  loop_level--;
+  line_number = save_line_number;
+
+#if 0
+  if (lexical_scoping)
+    {
+      if (!old_value)
+        unbind_variable (identifier);
+      else
+	{
+	  SHELL_VAR *new_value;
+
+	  new_value = bind_variable (identifier, value_cell(old_value), 0);
+	  new_value->attributes = old_value->attributes;
+	  dispose_variable (old_value);
+	}
+    }
+#endif
+
+  dispose_words (releaser);
+  discard_unwind_frame ("for");
+  return (retval);
+}
+
+#if defined (ARITH_FOR_COMMAND)
+/* Execute an arithmetic for command.  The syntax is
+
+	for (( init ; step ; test ))
+	do
+		body
+	done
+
+   The execution should be exactly equivalent to
+
+	eval \(\( init \)\)
+	while eval \(\( test \)\) ; do
+		body;
+		eval \(\( step \)\)
+	done
+*/
+static intmax_t
+eval_arith_for_expr (l, okp)
+     WORD_LIST *l;
+     int *okp;
+{
+  WORD_LIST *new;
+  intmax_t expresult;
+  int r;
+
+  new = expand_words_no_vars (l);
+  if (new)
+    {
+      if (echo_command_at_execute)
+	xtrace_print_arith_cmd (new);
+      this_command_name = "((";		/* )) for expression error messages */
+
+      command_string_index = 0;
+      print_arith_command (new);
+      if (signal_in_progress (DEBUG_TRAP) == 0)
+	{
+	  FREE (the_printed_command_except_trap);
+	  the_printed_command_except_trap = savestring (the_printed_command);
+	}
+
+      r = run_debug_trap ();
+      /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+	 skip the command. */
+#if defined (DEBUGGER)
+      if (debugging_mode == 0 || r == EXECUTION_SUCCESS)
+	expresult = evalexp (new->word->word, okp);
+      else
+	{
+	  expresult = 0;
+	  if (okp)
+	    *okp = 1;
+	}
+#else
+      expresult = evalexp (new->word->word, okp);
+#endif
+      dispose_words (new);
+    }
+  else
+    {
+      expresult = 0;
+      if (okp)
+	*okp = 1;
+    }
+  return (expresult);
+}
+
+static int
+execute_arith_for_command (arith_for_command)
+     ARITH_FOR_COM *arith_for_command;
+{
+  intmax_t expresult;
+  int expok, body_status, arith_lineno, save_lineno;
+
+  body_status = EXECUTION_SUCCESS;
+  loop_level++;
+  save_lineno = line_number;
+
+  if (arith_for_command->flags & CMD_IGNORE_RETURN)
+    arith_for_command->action->flags |= CMD_IGNORE_RETURN;
+
+  this_command_name = "((";	/* )) for expression error messages */
+
+  /* save the starting line number of the command so we can reset
+     line_number before executing each expression -- for $LINENO
+     and the DEBUG trap. */
+  line_number = arith_lineno = arith_for_command->line;
+  if (variable_context && interactive_shell)
+    line_number -= function_line_number;
+
+  /* Evaluate the initialization expression. */
+  expresult = eval_arith_for_expr (arith_for_command->init, &expok);
+  if (expok == 0)
+    {
+      line_number = save_lineno;
+      return (EXECUTION_FAILURE);
+    }
+
+  while (1)
+    {
+      /* Evaluate the test expression. */
+      line_number = arith_lineno;
+      expresult = eval_arith_for_expr (arith_for_command->test, &expok);
+      line_number = save_lineno;
+
+      if (expok == 0)
+	{
+	  body_status = EXECUTION_FAILURE;
+	  break;
+	}
+      REAP ();
+      if (expresult == 0)
+	break;
+
+      /* Execute the body of the arithmetic for command. */
+      QUIT;
+      body_status = execute_command (arith_for_command->action);
+      QUIT;
+
+      /* Handle any `break' or `continue' commands executed by the body. */
+      if (breaking)
+	{
+	  breaking--;
+	  break;
+	}
+
+      if (continuing)
+	{
+	  continuing--;
+	  if (continuing)
+	    break;
+	}
+
+      /* Evaluate the step expression. */
+      line_number = arith_lineno;
+      expresult = eval_arith_for_expr (arith_for_command->step, &expok);
+      line_number = save_lineno;
+
+      if (expok == 0)
+	{
+	  body_status = EXECUTION_FAILURE;
+	  break;
+	}
+    }
+
+  loop_level--;
+  line_number = save_lineno;
+
+  return (body_status);
+}
+#endif
+
+#if defined (SELECT_COMMAND)
+static int LINES, COLS, tabsize;
+
+#define RP_SPACE ") "
+#define RP_SPACE_LEN 2
+
+/* XXX - does not handle numbers > 1000000 at all. */
+#define NUMBER_LEN(s) \
+((s < 10) ? 1 \
+	  : ((s < 100) ? 2 \
+		      : ((s < 1000) ? 3 \
+				   : ((s < 10000) ? 4 \
+						 : ((s < 100000) ? 5 \
+								: 6)))))
+
+static int
+print_index_and_element (len, ind, list)
+      int len, ind;
+      WORD_LIST *list;
+{
+  register WORD_LIST *l;
+  register int i;
+
+  if (list == 0)
+    return (0);
+  for (i = ind, l = list; l && --i; l = l->next)
+    ;
+  fprintf (stderr, "%*d%s%s", len, ind, RP_SPACE, l->word->word);
+  return (STRLEN (l->word->word));
+}
+
+static void
+indent (from, to)
+     int from, to;
+{
+  while (from < to)
+    {
+      if ((to / tabsize) > (from / tabsize))
+	{
+	  putc ('\t', stderr);
+	  from += tabsize - from % tabsize;
+	}
+      else
+	{
+	  putc (' ', stderr);
+	  from++;
+	}
+    }
+}
+
+static void
+print_select_list (list, list_len, max_elem_len, indices_len)
+     WORD_LIST *list;
+     int list_len, max_elem_len, indices_len;
+{
+  int ind, row, elem_len, pos, cols, rows;
+  int first_column_indices_len, other_indices_len;
+
+  if (list == 0)
+    {
+      putc ('\n', stderr);
+      return;
+    }
+
+  cols = max_elem_len ? COLS / max_elem_len : 1;
+  if (cols == 0)
+    cols = 1;
+  rows = list_len ? list_len / cols + (list_len % cols != 0) : 1;
+  cols = list_len ? list_len / rows + (list_len % rows != 0) : 1;
+
+  if (rows == 1)
+    {
+      rows = cols;
+      cols = 1;
+    }
+
+  first_column_indices_len = NUMBER_LEN (rows);
+  other_indices_len = indices_len;
+
+  for (row = 0; row < rows; row++)
+    {
+      ind = row;
+      pos = 0;
+      while (1)
+	{
+	  indices_len = (pos == 0) ? first_column_indices_len : other_indices_len;
+	  elem_len = print_index_and_element (indices_len, ind + 1, list);
+	  elem_len += indices_len + RP_SPACE_LEN;
+	  ind += rows;
+	  if (ind >= list_len)
+	    break;
+	  indent (pos + elem_len, pos + max_elem_len);
+	  pos += max_elem_len;
+	}
+      putc ('\n', stderr);
+    }
+}
+
+/* Print the elements of LIST, one per line, preceded by an index from 1 to
+   LIST_LEN.  Then display PROMPT and wait for the user to enter a number.
+   If the number is between 1 and LIST_LEN, return that selection.  If EOF
+   is read, return a null string.  If a blank line is entered, or an invalid
+   number is entered, the loop is executed again. */
+static char *
+select_query (list, list_len, prompt, print_menu)
+     WORD_LIST *list;
+     int list_len;
+     char *prompt;
+     int print_menu;
+{
+  int max_elem_len, indices_len, len;
+  intmax_t reply;
+  WORD_LIST *l;
+  char *repl_string, *t;
+
+  t = get_string_value ("LINES");
+  LINES = (t && *t) ? atoi (t) : 24;
+  t = get_string_value ("COLUMNS");
+  COLS =  (t && *t) ? atoi (t) : 80;
+
+#if 0
+  t = get_string_value ("TABSIZE");
+  tabsize = (t && *t) ? atoi (t) : 8;
+  if (tabsize <= 0)
+    tabsize = 8;
+#else
+  tabsize = 8;
+#endif
+
+  max_elem_len = 0;
+  for (l = list; l; l = l->next)
+    {
+      len = STRLEN (l->word->word);
+      if (len > max_elem_len)
+	max_elem_len = len;
+    }
+  indices_len = NUMBER_LEN (list_len);
+  max_elem_len += indices_len + RP_SPACE_LEN + 2;
+
+  while (1)
+    {
+      if (print_menu)
+	print_select_list (list, list_len, max_elem_len, indices_len);
+      fprintf (stderr, "%s", prompt);
+      fflush (stderr);
+      QUIT;
+
+      if (read_builtin ((WORD_LIST *)NULL) == EXECUTION_FAILURE)
+	{
+	  putchar ('\n');
+	  return ((char *)NULL);
+	}
+      repl_string = get_string_value ("REPLY");
+      if (*repl_string == 0)
+	{
+	  print_menu = 1;
+	  continue;
+	}
+      if (legal_number (repl_string, &reply) == 0)
+	return "";
+      if (reply < 1 || reply > list_len)
+	return "";
+
+      for (l = list; l && --reply; l = l->next)
+	;
+      return (l->word->word);
+    }
+}
+
+/* Execute a SELECT command.  The syntax is:
+   SELECT word IN list DO command_list DONE
+   Only `break' or `return' in command_list will terminate
+   the command. */
+static int
+execute_select_command (select_command)
+     SELECT_COM *select_command;
+{
+  WORD_LIST *releaser, *list;
+  SHELL_VAR *v;
+  char *identifier, *ps3_prompt, *selection;
+  int retval, list_len, show_menu, save_line_number;
+
+  if (check_identifier (select_command->name, 1) == 0)
+    return (EXECUTION_FAILURE);
+
+  save_line_number = line_number;
+  line_number = select_command->line;
+
+  command_string_index = 0;
+  print_select_command_head (select_command);
+
+  if (echo_command_at_execute)
+    xtrace_print_select_command_head (select_command);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+    {
+      FREE (the_printed_command_except_trap);
+      the_printed_command_except_trap = savestring (the_printed_command);
+    }
+
+  retval = run_debug_trap ();
+#if defined (DEBUGGER)
+  /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+     skip the command. */
+  if (debugging_mode && retval != EXECUTION_SUCCESS)
+    return (EXECUTION_SUCCESS);
+#endif
+
+  loop_level++;
+  identifier = select_command->name->word;
+
+  /* command and arithmetic substitution, parameter and variable expansion,
+     word splitting, pathname expansion, and quote removal. */
+  list = releaser = expand_words_no_vars (select_command->map_list);
+  list_len = list_length (list);
+  if (list == 0 || list_len == 0)
+    {
+      if (list)
+	dispose_words (list);
+      line_number = save_line_number;
+      return (EXECUTION_SUCCESS);
+    }
+
+  begin_unwind_frame ("select");
+  add_unwind_protect (dispose_words, releaser);
+
+  if (select_command->flags & CMD_IGNORE_RETURN)
+    select_command->action->flags |= CMD_IGNORE_RETURN;
+
+  retval = EXECUTION_SUCCESS;
+  show_menu = 1;
+
+  while (1)
+    {
+      line_number = select_command->line;
+      ps3_prompt = get_string_value ("PS3");
+      if (ps3_prompt == 0)
+	ps3_prompt = "#? ";
+
+      QUIT;
+      selection = select_query (list, list_len, ps3_prompt, show_menu);
+      QUIT;
+      if (selection == 0)
+	{
+	  /* select_query returns EXECUTION_FAILURE if the read builtin
+	     fails, so we want to return failure in this case. */
+	  retval = EXECUTION_FAILURE;
+	  break;
+	}
+
+      v = bind_variable (identifier, selection, 0);
+      if (readonly_p (v) || noassign_p (v))
+	{
+	  if (readonly_p (v) && interactive_shell == 0 && posixly_correct)
+	    {
+	      last_command_exit_value = EXECUTION_FAILURE;
+	      jump_to_top_level (FORCE_EOF);
+	    }
+	  else
+	    {
+	      dispose_words (releaser);
+	      discard_unwind_frame ("select");
+	      loop_level--;
+	      line_number = save_line_number;
+	      return (EXECUTION_FAILURE);
+	    }
+	}
+
+      retval = execute_command (select_command->action);
+
+      REAP ();
+      QUIT;
+
+      if (breaking)
+	{
+	  breaking--;
+	  break;
+	}
+
+      if (continuing)
+	{
+	  continuing--;
+	  if (continuing)
+	    break;
+	}
+
+#if defined (KSH_COMPATIBLE_SELECT)
+      show_menu = 0;
+      selection = get_string_value ("REPLY");
+      if (selection && *selection == '\0')
+        show_menu = 1;
+#endif
+    }
+
+  loop_level--;
+  line_number = save_line_number;
+
+  dispose_words (releaser);
+  discard_unwind_frame ("select");
+  return (retval);
+}
+#endif /* SELECT_COMMAND */
+
+/* Execute a CASE command.  The syntax is: CASE word_desc IN pattern_list ESAC.
+   The pattern_list is a linked list of pattern clauses; each clause contains
+   some patterns to compare word_desc against, and an associated command to
+   execute. */
+static int
+execute_case_command (case_command)
+     CASE_COM *case_command;
+{
+  register WORD_LIST *list;
+  WORD_LIST *wlist, *es;
+  PATTERN_LIST *clauses;
+  char *word, *pattern;
+  int retval, match, ignore_return, save_line_number;
+
+  save_line_number = line_number;
+  line_number = case_command->line;
+
+  command_string_index = 0;
+  print_case_command_head (case_command);
+
+  if (echo_command_at_execute)
+    xtrace_print_case_command_head (case_command);
+
+  if (signal_in_progress (DEBUG_TRAP == 0) && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+    {
+      FREE (the_printed_command_except_trap);
+      the_printed_command_except_trap = savestring (the_printed_command);
+    }
+
+  retval = run_debug_trap();
+#if defined (DEBUGGER)
+  /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+     skip the command. */
+  if (debugging_mode && retval != EXECUTION_SUCCESS)
+    {
+      line_number = save_line_number;
+      return (EXECUTION_SUCCESS);
+    }
+#endif
+
+  wlist = expand_word_unsplit (case_command->word, 0);
+  word = wlist ? string_list (wlist) : savestring ("");
+  dispose_words (wlist);
+
+  retval = EXECUTION_SUCCESS;
+  ignore_return = case_command->flags & CMD_IGNORE_RETURN;
+
+  begin_unwind_frame ("case");
+  add_unwind_protect ((Function *)xfree, word);
+
+#define EXIT_CASE()  goto exit_case_command
+
+  for (clauses = case_command->clauses; clauses; clauses = clauses->next)
+    {
+      QUIT;
+      for (list = clauses->patterns; list; list = list->next)
+	{
+	  es = expand_word_leave_quoted (list->word, 0);
+
+	  if (es && es->word && es->word->word && *(es->word->word))
+	    pattern = quote_string_for_globbing (es->word->word, QGLOB_CVTNULL);
+	  else
+	    {
+	      pattern = (char *)xmalloc (1);
+	      pattern[0] = '\0';
+	    }
+
+	  /* Since the pattern does not undergo quote removal (as per
+	     Posix.2, section 3.9.4.3), the strmatch () call must be able
+	     to recognize backslashes as escape characters. */
+	  match = strmatch (pattern, word, FNMATCH_EXTFLAG|FNMATCH_IGNCASE) != FNM_NOMATCH;
+	  free (pattern);
+
+	  dispose_words (es);
+
+	  if (match)
+	    {
+	      if (clauses->action && ignore_return)
+		clauses->action->flags |= CMD_IGNORE_RETURN;
+	      retval = execute_command (clauses->action);
+	      EXIT_CASE ();
+	    }
+
+	  QUIT;
+	}
+    }
+
+exit_case_command:
+  free (word);
+  discard_unwind_frame ("case");
+  line_number = save_line_number;
+  return (retval);
+}
+
+#define CMD_WHILE 0
+#define CMD_UNTIL 1
+
+/* The WHILE command.  Syntax: WHILE test DO action; DONE.
+   Repeatedly execute action while executing test produces
+   EXECUTION_SUCCESS. */
+static int
+execute_while_command (while_command)
+     WHILE_COM *while_command;
+{
+  return (execute_while_or_until (while_command, CMD_WHILE));
+}
+
+/* UNTIL is just like WHILE except that the test result is negated. */
+static int
+execute_until_command (while_command)
+     WHILE_COM *while_command;
+{
+  return (execute_while_or_until (while_command, CMD_UNTIL));
+}
+
+/* The body for both while and until.  The only difference between the
+   two is that the test value is treated differently.  TYPE is
+   CMD_WHILE or CMD_UNTIL.  The return value for both commands should
+   be EXECUTION_SUCCESS if no commands in the body are executed, and
+   the status of the last command executed in the body otherwise. */
+static int
+execute_while_or_until (while_command, type)
+     WHILE_COM *while_command;
+     int type;
+{
+  int return_value, body_status;
+
+  body_status = EXECUTION_SUCCESS;
+  loop_level++;
+
+  while_command->test->flags |= CMD_IGNORE_RETURN;
+  if (while_command->flags & CMD_IGNORE_RETURN)
+    while_command->action->flags |= CMD_IGNORE_RETURN;
+
+  while (1)
+    {
+      return_value = execute_command (while_command->test);
+      REAP ();
+
+      /* Need to handle `break' in the test when we would break out of the
+         loop.  The job control code will set `breaking' to loop_level
+         when a job in a loop is stopped with SIGTSTP.  If the stopped job
+         is in the loop test, `breaking' will not be reset unless we do
+         this, and the shell will cease to execute commands. */
+      if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS)
+	{
+	  if (breaking)
+	    breaking--;
+	  break;
+	}
+      if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS)
+	{
+	  if (breaking)
+	    breaking--;
+	  break;
+	}
+
+      QUIT;
+      body_status = execute_command (while_command->action);
+      QUIT;
+
+      if (breaking)
+	{
+	  breaking--;
+	  break;
+	}
+
+      if (continuing)
+	{
+	  continuing--;
+	  if (continuing)
+	    break;
+	}
+    }
+  loop_level--;
+
+  return (body_status);
+}
+
+/* IF test THEN command [ELSE command].
+   IF also allows ELIF in the place of ELSE IF, but
+   the parser makes *that* stupidity transparent. */
+static int
+execute_if_command (if_command)
+     IF_COM *if_command;
+{
+  int return_value, save_line_number;
+
+  save_line_number = line_number;
+  if_command->test->flags |= CMD_IGNORE_RETURN;
+  return_value = execute_command (if_command->test);
+  line_number = save_line_number;
+
+  if (return_value == EXECUTION_SUCCESS)
+    {
+      QUIT;
+
+      if (if_command->true_case && (if_command->flags & CMD_IGNORE_RETURN))
+	if_command->true_case->flags |= CMD_IGNORE_RETURN;
+
+      return (execute_command (if_command->true_case));
+    }
+  else
+    {
+      QUIT;
+
+      if (if_command->false_case && (if_command->flags & CMD_IGNORE_RETURN))
+	if_command->false_case->flags |= CMD_IGNORE_RETURN;
+
+      return (execute_command (if_command->false_case));
+    }
+}
+
+#if defined (DPAREN_ARITHMETIC)
+static int
+execute_arith_command (arith_command)
+     ARITH_COM *arith_command;
+{
+  int expok, save_line_number, retval;
+  intmax_t expresult;
+  WORD_LIST *new;
+
+  expresult = 0;
+
+  save_line_number = line_number;
+  this_command_name = "((";	/* )) */
+  line_number = arith_command->line;
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell)
+    line_number -= function_line_number;
+
+  command_string_index = 0;
+  print_arith_command (arith_command->exp);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0)
+    {
+      FREE (the_printed_command_except_trap);
+      the_printed_command_except_trap = savestring (the_printed_command);
+    }
+
+  /* Run the debug trap before each arithmetic command, but do it after we
+     update the line number information and before we expand the various
+     words in the expression. */
+  retval = run_debug_trap ();
+#if defined (DEBUGGER)
+  /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+     skip the command. */
+  if (debugging_mode && retval != EXECUTION_SUCCESS)
+    {
+      line_number = save_line_number;
+      return (EXECUTION_SUCCESS);
+    }
+#endif
+
+  new = expand_words_no_vars (arith_command->exp);
+
+  /* If we're tracing, make a new word list with `((' at the front and `))'
+     at the back and print it. */
+  if (echo_command_at_execute)
+    xtrace_print_arith_cmd (new);
+
+  if (new)
+    {
+      expresult = evalexp (new->word->word, &expok);
+      line_number = save_line_number;
+      dispose_words (new);
+    }
+  else
+    {
+      expresult = 0;
+      expok = 1;
+    }
+
+  if (expok == 0)
+    return (EXECUTION_FAILURE);
+
+  return (expresult == 0 ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+}
+#endif /* DPAREN_ARITHMETIC */
+
+#if defined (COND_COMMAND)
+
+static char *nullstr = "";
+
+static int
+execute_cond_node (cond)
+     COND_COM *cond;
+{
+  int result, invert, patmatch, rmatch, mflags;
+  char *arg1, *arg2;
+
+  invert = (cond->flags & CMD_INVERT_RETURN);
+
+  if (cond->type == COND_EXPR)
+    result = execute_cond_node (cond->left);
+  else if (cond->type == COND_OR)
+    {
+      result = execute_cond_node (cond->left);
+      if (result != EXECUTION_SUCCESS)
+	result = execute_cond_node (cond->right);
+    }
+  else if (cond->type == COND_AND)
+    {
+      result = execute_cond_node (cond->left);
+      if (result == EXECUTION_SUCCESS)
+	result = execute_cond_node (cond->right);
+    }
+  else if (cond->type == COND_UNARY)
+    {
+      arg1 = cond_expand_word (cond->left->op, 0);
+      if (arg1 == 0)
+	arg1 = nullstr;
+      if (echo_command_at_execute)
+	xtrace_print_cond_term (cond->type, invert, cond->op, arg1, (char *)NULL);
+      result = unary_test (cond->op->word, arg1) ? EXECUTION_SUCCESS : EXECUTION_FAILURE;
+      if (arg1 != nullstr)
+	free (arg1);
+    }
+  else if (cond->type == COND_BINARY)
+    {
+      patmatch = ((cond->op->word[1] == '=') && (cond->op->word[2] == '\0') &&
+		  (cond->op->word[0] == '!' || cond->op->word[0] == '=') ||
+		  (cond->op->word[0] == '=' && cond->op->word[1] == '\0'));
+#if defined (COND_REGEXP)
+      rmatch = (cond->op->word[0] == '=' && cond->op->word[1] == '~' &&
+		cond->op->word[2] == '\0');
+#endif
+
+      arg1 = cond_expand_word (cond->left->op, 0);
+      if (arg1 == 0)
+	arg1 = nullstr;
+      arg2 = cond_expand_word (cond->right->op, patmatch);
+      if (arg2 == 0)
+	arg2 = nullstr;
+
+      if (echo_command_at_execute)
+	xtrace_print_cond_term (cond->type, invert, cond->op, arg1, arg2);
+
+#if defined (COND_REGEXP)
+      if (rmatch)
+	{
+	  mflags = SHMAT_PWARN;
+#if defined (ARRAY_VARS)
+	  mflags |= SHMAT_SUBEXP;
+#endif
+
+	  result = sh_regmatch (arg1, arg2, mflags);
+	}
+      else
+#endif /* COND_REGEXP */
+	{
+	  int oe;
+	  oe = extended_glob;
+	  extended_glob = 1;
+	  result = binary_test (cond->op->word, arg1, arg2, TEST_PATMATCH|TEST_ARITHEXP)
+				  ? EXECUTION_SUCCESS
+				  : EXECUTION_FAILURE;
+	  extended_glob = oe;
+	}
+      if (arg1 != nullstr)
+	free (arg1);
+      if (arg2 != nullstr)
+	free (arg2);
+    }
+  else
+    {
+      command_error ("execute_cond_node", CMDERR_BADTYPE, cond->type, 0);
+      jump_to_top_level (DISCARD);
+      result = EXECUTION_FAILURE;
+    }
+
+  if (invert)
+    result = (result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS;
+
+  return result;
+}
+
+static int
+execute_cond_command (cond_command)
+     COND_COM *cond_command;
+{
+  int retval, save_line_number;
+
+  retval = EXECUTION_SUCCESS;
+  save_line_number = line_number;
+
+  this_command_name = "[[";
+  line_number = cond_command->line;
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell)
+    line_number -= function_line_number;
+
+  command_string_index = 0;
+  print_cond_command (cond_command);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0)
+    {
+      FREE (the_printed_command_except_trap);
+      the_printed_command_except_trap = savestring (the_printed_command);
+    }
+
+  /* Run the debug trap before each conditional command, but do it after we
+     update the line number information. */
+  retval = run_debug_trap ();
+#if defined (DEBUGGER)
+  /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+     skip the command. */
+  if (debugging_mode && retval != EXECUTION_SUCCESS)
+    {
+      line_number = save_line_number;
+      return (EXECUTION_SUCCESS);
+    }
+#endif
+
+#if 0
+  debug_print_cond_command (cond_command);
+#endif
+
+  last_command_exit_value = retval = execute_cond_node (cond_command);
+  line_number = save_line_number;
+  return (retval);
+}
+#endif /* COND_COMMAND */
+
+static void
+bind_lastarg (arg)
+     char *arg;
+{
+  SHELL_VAR *var;
+
+  if (arg == 0)
+    arg = "";
+  var = bind_variable ("_", arg, 0);
+  VUNSETATTR (var, att_exported);
+}
+
+/* Execute a null command.  Fork a subshell if the command uses pipes or is
+   to be run asynchronously.  This handles all the side effects that are
+   supposed to take place. */
+static int
+execute_null_command (redirects, pipe_in, pipe_out, async)
+     REDIRECT *redirects;
+     int pipe_in, pipe_out, async;
+{
+  int r;
+
+  if (pipe_in != NO_PIPE || pipe_out != NO_PIPE || async)
+    {
+      /* We have a null command, but we really want a subshell to take
+	 care of it.  Just fork, do piping and redirections, and exit. */
+      if (make_child ((char *)NULL, async) == 0)
+	{
+	  /* Cancel traps, in trap.c. */
+	  restore_original_signals ();		/* XXX */
+
+	  do_piping (pipe_in, pipe_out);
+
+	  subshell_environment = SUBSHELL_ASYNC;
+
+	  if (do_redirections (redirects, RX_ACTIVE) == 0)
+	    exit (EXECUTION_SUCCESS);
+	  else
+	    exit (EXECUTION_FAILURE);
+	}
+      else
+	{
+	  close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+	  unlink_fifo_list ();
+#endif
+	  return (EXECUTION_SUCCESS);
+	}
+    }
+  else
+    {
+      /* Even if there aren't any command names, pretend to do the
+	 redirections that are specified.  The user expects the side
+	 effects to take place.  If the redirections fail, then return
+	 failure.  Otherwise, if a command substitution took place while
+	 expanding the command or a redirection, return the value of that
+	 substitution.  Otherwise, return EXECUTION_SUCCESS. */
+
+      r = do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE);
+      cleanup_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+
+      if (r != 0)
+	return (EXECUTION_FAILURE);
+      else if (last_command_subst_pid != NO_PID)
+	return (last_command_exit_value);
+      else
+	return (EXECUTION_SUCCESS);
+    }
+}
+
+/* This is a hack to suppress word splitting for assignment statements
+   given as arguments to builtins with the ASSIGNMENT_BUILTIN flag set. */
+static void
+fix_assignment_words (words)
+     WORD_LIST *words;
+{
+  WORD_LIST *w;
+  struct builtin *b;
+
+  if (words == 0)
+    return;
+
+  b = 0;
+
+  for (w = words; w; w = w->next)
+    if (w->word->flags & W_ASSIGNMENT)
+      {
+	if (b == 0)
+	  {
+	    b = builtin_address_internal (words->word->word, 0);
+	    if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
+	      return;
+	    else if (b && (b->flags & ASSIGNMENT_BUILTIN))
+	      words->word->flags |= W_ASSNBLTIN;
+	  }
+	w->word->flags |= (W_NOSPLIT|W_NOGLOB|W_TILDEEXP|W_ASSIGNARG);
+      }
+}
+
+/* The meaty part of all the executions.  We have to start hacking the
+   real execution of commands here.  Fork a process, set things up,
+   execute the command. */
+static int
+execute_simple_command (simple_command, pipe_in, pipe_out, async, fds_to_close)
+     SIMPLE_COM *simple_command;
+     int pipe_in, pipe_out, async;
+     struct fd_bitmap *fds_to_close;
+{
+  WORD_LIST *words, *lastword;
+  char *command_line, *lastarg, *temp;
+  int first_word_quoted, result, builtin_is_special, already_forked, dofork;
+  pid_t old_last_async_pid;
+  sh_builtin_func_t *builtin;
+  SHELL_VAR *func;
+
+  result = EXECUTION_SUCCESS;
+  special_builtin_failed = builtin_is_special = 0;
+  command_line = (char *)0;
+
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell)
+    line_number -= function_line_number;
+
+  /* Remember what this command line looks like at invocation. */
+  command_string_index = 0;
+  print_simple_command (simple_command);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+    {
+      FREE (the_printed_command_except_trap);
+      the_printed_command_except_trap = the_printed_command ? savestring (the_printed_command) : (char *)0;
+    }
+
+  /* Run the debug trap before each simple command, but do it after we
+     update the line number information. */
+  result = run_debug_trap ();
+#if defined (DEBUGGER)
+  /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+     skip the command. */
+  if (debugging_mode && result != EXECUTION_SUCCESS)
+    return (EXECUTION_SUCCESS);
+#endif
+
+  first_word_quoted =
+    simple_command->words ? (simple_command->words->word->flags & W_QUOTED): 0;
+
+  last_command_subst_pid = NO_PID;
+  old_last_async_pid = last_asynchronous_pid;
+
+  already_forked = dofork = 0;
+
+  /* If we're in a pipeline or run in the background, set DOFORK so we
+     make the child early, before word expansion.  This keeps assignment
+     statements from affecting the parent shell's environment when they
+     should not. */
+  dofork = pipe_in != NO_PIPE || pipe_out != NO_PIPE || async;
+
+  /* Something like `%2 &' should restart job 2 in the background, not cause
+     the shell to fork here. */
+  if (dofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE &&
+	simple_command->words && simple_command->words->word &&
+	simple_command->words->word->word &&
+	(simple_command->words->word->word[0] == '%'))
+    dofork = 0;
+
+  if (dofork)
+    {
+      /* Do this now, because execute_disk_command will do it anyway in the
+	 vast majority of cases. */
+      maybe_make_export_env ();
+
+      /* Don't let a DEBUG trap overwrite the command string to be saved with
+	 the process/job associated with this child. */
+      if (make_child (savestring (the_printed_command_except_trap), async) == 0)
+	{
+	  already_forked = 1;
+	  simple_command->flags |= CMD_NO_FORK;
+
+	  subshell_environment = SUBSHELL_FORK;
+	  if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+	    subshell_environment |= SUBSHELL_PIPE;
+	  if (async)
+	    subshell_environment |= SUBSHELL_ASYNC;
+
+	  /* We need to do this before piping to handle some really
+	     pathological cases where one of the pipe file descriptors
+	     is < 2. */
+	  if (fds_to_close)
+	    close_fd_bitmap (fds_to_close);
+
+	  do_piping (pipe_in, pipe_out);
+	  pipe_in = pipe_out = NO_PIPE;
+
+	  last_asynchronous_pid = old_last_async_pid;
+	}
+      else
+	{
+	  close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+	  unlink_fifo_list ();
+#endif
+	  command_line = (char *)NULL;      /* don't free this. */
+	  bind_lastarg ((char *)NULL);
+	  return (result);
+	}
+    }
+
+  /* If we are re-running this as the result of executing the `command'
+     builtin, do not expand the command words a second time. */
+  if ((simple_command->flags & CMD_INHIBIT_EXPANSION) == 0)
+    {
+      current_fds_to_close = fds_to_close;
+      fix_assignment_words (simple_command->words);
+      words = expand_words (simple_command->words);
+      current_fds_to_close = (struct fd_bitmap *)NULL;
+    }
+  else
+    words = copy_word_list (simple_command->words);
+
+  /* It is possible for WORDS not to have anything left in it.
+     Perhaps all the words consisted of `$foo', and there was
+     no variable `$foo'. */
+  if (words == 0)
+    {
+      this_command_name = 0;
+      result = execute_null_command (simple_command->redirects,
+				     pipe_in, pipe_out,
+				     already_forked ? 0 : async);
+      if (already_forked)
+	exit (result);
+      else
+	{
+	  bind_lastarg ((char *)NULL);
+	  set_pipestatus_from_exit (result);
+	  return (result);
+	}
+    }
+
+  lastarg = (char *)NULL;
+
+  begin_unwind_frame ("simple-command");
+
+  if (echo_command_at_execute)
+    xtrace_print_word_list (words, 1);
+
+  builtin = (sh_builtin_func_t *)NULL;
+  func = (SHELL_VAR *)NULL;
+  if ((simple_command->flags & CMD_NO_FUNCTIONS) == 0)
+    {
+      /* Posix.2 says special builtins are found before functions.  We
+	 don't set builtin_is_special anywhere other than here, because
+	 this path is followed only when the `command' builtin is *not*
+	 being used, and we don't want to exit the shell if a special
+	 builtin executed with `command builtin' fails.  `command' is not
+	 a special builtin. */
+      if (posixly_correct)
+	{
+	  builtin = find_special_builtin (words->word->word);
+	  if (builtin)
+	    builtin_is_special = 1;
+	}
+      if (builtin == 0)
+	func = find_function (words->word->word);
+    }
+
+  /* In POSIX mode, assignment errors in the temporary environment cause a
+     non-interactive shell to exit. */
+  if (builtin_is_special && interactive_shell == 0 && tempenv_assign_error)
+    {
+      last_command_exit_value = EXECUTION_FAILURE;
+      jump_to_top_level (ERREXIT);
+    }
+
+  add_unwind_protect (dispose_words, words);
+  QUIT;
+
+  /* Bind the last word in this command to "$_" after execution. */
+  for (lastword = words; lastword->next; lastword = lastword->next)
+    ;
+  lastarg = lastword->word->word;
+
+#if defined (JOB_CONTROL)
+  /* Is this command a job control related thing? */
+  if (words->word->word[0] == '%' && already_forked == 0)
+    {
+      this_command_name = async ? "bg" : "fg";
+      last_shell_builtin = this_shell_builtin;
+      this_shell_builtin = builtin_address (this_command_name);
+      result = (*this_shell_builtin) (words);
+      goto return_result;
+    }
+
+  /* One other possiblilty.  The user may want to resume an existing job.
+     If they do, find out whether this word is a candidate for a running
+     job. */
+  if (job_control && already_forked == 0 && async == 0 &&
+	!first_word_quoted &&
+	!words->next &&
+	words->word->word[0] &&
+	!simple_command->redirects &&
+	pipe_in == NO_PIPE &&
+	pipe_out == NO_PIPE &&
+	(temp = get_string_value ("auto_resume")))
+    {
+      int job, jflags, started_status;
+
+      jflags = JM_STOPPED|JM_FIRSTMATCH;
+      if (STREQ (temp, "exact"))
+	jflags |= JM_EXACT;
+      else if (STREQ (temp, "substring"))
+	jflags |= JM_SUBSTRING;
+      else
+	jflags |= JM_PREFIX;
+      job = get_job_by_name (words->word->word, jflags);
+      if (job != NO_JOB)
+	{
+	  run_unwind_frame ("simple-command");
+	  this_command_name = "fg";
+	  last_shell_builtin = this_shell_builtin;
+	  this_shell_builtin = builtin_address ("fg");
+
+	  started_status = start_job (job, 1);
+	  return ((started_status < 0) ? EXECUTION_FAILURE : started_status);
+	}
+    }
+#endif /* JOB_CONTROL */
+
+  /* Remember the name of this command globally. */
+  this_command_name = words->word->word;
+
+  QUIT;
+
+  /* This command could be a shell builtin or a user-defined function.
+     We have already found special builtins by this time, so we do not
+     set builtin_is_special.  If this is a function or builtin, and we
+     have pipes, then fork a subshell in here.  Otherwise, just execute
+     the command directly. */
+  if (func == 0 && builtin == 0)
+    builtin = find_shell_builtin (this_command_name);
+
+  last_shell_builtin = this_shell_builtin;
+  this_shell_builtin = builtin;
+
+  if (builtin || func)
+    {
+      if (already_forked)
+	{
+	  /* reset_terminating_signals (); */	/* XXX */
+	  /* Cancel traps, in trap.c. */
+	  restore_original_signals ();
+
+	  if (async)
+	    {
+	      if ((simple_command->flags & CMD_STDIN_REDIR) &&
+		    pipe_in == NO_PIPE &&
+		    (stdin_redirects (simple_command->redirects) == 0))
+		async_redirect_stdin ();
+	      setup_async_signals ();
+	    }
+
+	  subshell_level++;
+	  execute_subshell_builtin_or_function
+	    (words, simple_command->redirects, builtin, func,
+	     pipe_in, pipe_out, async, fds_to_close,
+	     simple_command->flags);
+	  subshell_level--;
+	}
+      else
+	{
+	  result = execute_builtin_or_function
+	    (words, builtin, func, simple_command->redirects, fds_to_close,
+	     simple_command->flags);
+	  if (builtin)
+	    {
+	      if (result > EX_SHERRBASE)
+		{
+		  result = builtin_status (result);
+		  if (builtin_is_special)
+		    special_builtin_failed = 1;
+		}
+	      /* In POSIX mode, if there are assignment statements preceding
+		 a special builtin, they persist after the builtin
+		 completes. */
+	      if (posixly_correct && builtin_is_special && temporary_env)
+		merge_temporary_env ();
+	    }
+	  else		/* function */
+	    {
+	      if (result == EX_USAGE)
+		result = EX_BADUSAGE;
+	      else if (result > EX_SHERRBASE)
+		result = EXECUTION_FAILURE;
+	    }
+
+	  set_pipestatus_from_exit (result);
+
+	  goto return_result;
+	}
+    }
+
+  if (command_line == 0)
+    command_line = savestring (the_printed_command);
+
+  execute_disk_command (words, simple_command->redirects, command_line,
+			pipe_in, pipe_out, async, fds_to_close,
+			simple_command->flags);
+
+ return_result:
+  bind_lastarg (lastarg);
+  FREE (command_line);
+  dispose_words (words);
+  discard_unwind_frame ("simple-command");
+  this_command_name = (char *)NULL;	/* points to freed memory now */
+  return (result);
+}
+
+/* Translate the special builtin exit statuses.  We don't really need a
+   function for this; it's a placeholder for future work. */
+static int
+builtin_status (result)
+     int result;
+{
+  int r;
+
+  switch (result)
+    {
+    case EX_USAGE:
+      r = EX_BADUSAGE;
+      break;
+    case EX_REDIRFAIL:
+    case EX_BADSYNTAX:
+    case EX_BADASSIGN:
+    case EX_EXPFAIL:
+      r = EXECUTION_FAILURE;
+      break;
+    default:
+      r = EXECUTION_SUCCESS;
+      break;
+    }
+  return (r);
+}
+
+static int
+execute_builtin (builtin, words, flags, subshell)
+     sh_builtin_func_t *builtin;
+     WORD_LIST *words;
+     int flags, subshell;
+{
+  int old_e_flag, result, eval_unwind;
+  int isbltinenv;
+
+  old_e_flag = exit_immediately_on_error;
+  /* The eval builtin calls parse_and_execute, which does not know about
+     the setting of flags, and always calls the execution functions with
+     flags that will exit the shell on an error if -e is set.  If the
+     eval builtin is being called, and we're supposed to ignore the exit
+     value of the command, we turn the -e flag off ourselves, then
+     restore it when the command completes. */
+  if (subshell == 0 && builtin == eval_builtin && (flags & CMD_IGNORE_RETURN))
+    {
+      begin_unwind_frame ("eval_builtin");
+      unwind_protect_int (exit_immediately_on_error);
+      exit_immediately_on_error = 0;
+      eval_unwind = 1;
+    }
+  else
+    eval_unwind = 0;
+
+  /* The temporary environment for a builtin is supposed to apply to
+     all commands executed by that builtin.  Currently, this is a
+     problem only with the `unset', `source' and `eval' builtins. */
+
+  isbltinenv = (builtin == source_builtin || builtin == eval_builtin || builtin == unset_builtin);
+
+  if (isbltinenv)
+    {
+      if (subshell == 0)
+	begin_unwind_frame ("builtin_env");
+
+      if (temporary_env)
+	{
+	  push_scope (VC_BLTNENV, temporary_env);
+	  if (subshell == 0)
+	    add_unwind_protect (pop_scope, (flags & CMD_COMMAND_BUILTIN) ? 0 : "1");
+          temporary_env = (HASH_TABLE *)NULL;	  
+	}
+    }
+
+  /* `return' does a longjmp() back to a saved environment in execute_function.
+     If a variable assignment list preceded the command, and the shell is
+     running in POSIX mode, we need to merge that into the shell_variables
+     table, since `return' is a POSIX special builtin. */
+  if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env)
+    {
+      begin_unwind_frame ("return_temp_env");
+      add_unwind_protect (merge_temporary_env, (char *)NULL);
+    }
+
+  result = ((*builtin) (words->next));
+
+  /* This shouldn't happen, but in case `return' comes back instead of
+     longjmp'ing, we need to unwind. */
+  if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env)
+    discard_unwind_frame ("return_temp_env");
+
+  if (subshell == 0 && isbltinenv)
+    run_unwind_frame ("builtin_env");
+
+  if (eval_unwind)
+    {
+      exit_immediately_on_error += old_e_flag;
+      discard_unwind_frame ("eval_builtin");
+    }
+
+  return (result);
+}
+
+static int
+execute_function (var, words, flags, fds_to_close, async, subshell)
+     SHELL_VAR *var;
+     WORD_LIST *words;
+     int flags;
+     struct fd_bitmap *fds_to_close;
+     int async, subshell;
+{
+  int return_val, result;
+  COMMAND *tc, *fc, *save_current;
+  char *debug_trap, *error_trap, *return_trap;
+#if defined (ARRAY_VARS)
+  SHELL_VAR *funcname_v, *nfv, *bash_source_v, *bash_lineno_v;
+  ARRAY *funcname_a, *bash_source_a, *bash_lineno_a;
+#endif
+  FUNCTION_DEF *shell_fn;
+  char *sfile, *t;
+  static int funcnest = 0;
+
+  USE_VAR(fc);
+
+#if defined (ARRAY_VARS)
+  GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
+  GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a);
+  GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a);
+#endif
+
+  tc = (COMMAND *)copy_command (function_cell (var));
+  if (tc && (flags & CMD_IGNORE_RETURN))
+    tc->flags |= CMD_IGNORE_RETURN;
+
+  if (subshell == 0)
+    {
+      begin_unwind_frame ("function_calling");
+      push_context (var->name, subshell, temporary_env);
+      add_unwind_protect (pop_context, (char *)NULL);
+      unwind_protect_int (line_number);
+      unwind_protect_int (return_catch_flag);
+      unwind_protect_jmp_buf (return_catch);
+      add_unwind_protect (dispose_command, (char *)tc);
+      unwind_protect_pointer (this_shell_function);
+      unwind_protect_int (loop_level);
+    }
+  else
+    push_context (var->name, subshell, temporary_env);	/* don't unwind-protect for subshells */
+
+  temporary_env = (HASH_TABLE *)NULL;
+
+  this_shell_function = var;
+  make_funcname_visible (1);
+
+  debug_trap = TRAP_STRING(DEBUG_TRAP);
+  error_trap = TRAP_STRING(ERROR_TRAP);
+  return_trap = TRAP_STRING(RETURN_TRAP);
+  
+  /* The order of the unwind protects for debug_trap, error_trap and
+     return_trap is important here!  unwind-protect commands are run
+     in reverse order of registration.  If this causes problems, take
+     out the xfree unwind-protect calls and live with the small memory leak. */
+
+  /* function_trace_mode != 0 means that all functions inherit the DEBUG trap.
+     if the function has the trace attribute set, it inherits the DEBUG trap */
+  if (debug_trap && ((trace_p (var) == 0) && function_trace_mode == 0))
+    {
+      if (subshell == 0)
+	{
+	  debug_trap = savestring (debug_trap);
+	  add_unwind_protect (xfree, debug_trap);
+	  add_unwind_protect (set_debug_trap, debug_trap);
+	}
+      restore_default_signal (DEBUG_TRAP);
+    }
+
+  /* error_trace_mode != 0 means that functions inherit the ERR trap. */
+  if (error_trap && error_trace_mode == 0)
+    {
+      if (subshell == 0)
+	{
+	  error_trap = savestring (error_trap);
+	  add_unwind_protect (xfree, error_trap);
+	  add_unwind_protect (set_error_trap, error_trap);
+	}
+      restore_default_signal (ERROR_TRAP);
+    }
+
+  /* Shell functions inherit the RETURN trap if function tracing is on
+     globally or on individually for this function. */
+#if 0
+  if (return_trap && ((trace_p (var) == 0) && function_trace_mode == 0))
+#else
+  if (return_trap && (signal_in_progress (DEBUG_TRAP) || ((trace_p (var) == 0) && function_trace_mode == 0)))
+#endif
+    {
+      if (subshell == 0)
+	{
+	  return_trap = savestring (return_trap);
+	  add_unwind_protect (xfree, return_trap);
+	  add_unwind_protect (set_return_trap, return_trap);
+	}
+      restore_default_signal (RETURN_TRAP);
+    }
+  
+  funcnest++;
+#if defined (ARRAY_VARS)
+  /* This is quite similar to the code in shell.c and elsewhere. */
+  shell_fn = find_function_def (this_shell_function->name);
+  sfile = shell_fn ? shell_fn->source_file : "";
+  array_push (funcname_a, this_shell_function->name);
+
+  array_push (bash_source_a, sfile);
+  t = itos (executing_line_number ());
+  array_push (bash_lineno_a, t);
+  free (t);
+#endif
+
+  /* The temporary environment for a function is supposed to apply to
+     all commands executed within the function body. */
+
+  remember_args (words->next, 1);
+
+  /* Update BASH_ARGV and BASH_ARGC */
+  if (debugging_mode)
+    push_args (words->next);
+
+  /* Number of the line on which the function body starts. */
+  line_number = function_line_number = tc->line;
+
+#if defined (JOB_CONTROL)
+  if (subshell)
+    stop_pipeline (async, (COMMAND *)NULL);
+#endif
+
+  fc = tc;
+
+  return_catch_flag++;
+  return_val = setjmp (return_catch);
+
+  if (return_val)
+    {
+      result = return_catch_value;
+      /* Run the RETURN trap in the function's context. */
+      save_current = currently_executing_command;
+      run_return_trap ();
+      currently_executing_command = save_current;
+    }
+  else
+    {
+      /* Run the debug trap here so we can trap at the start of a function's
+	 execution rather than the execution of the body's first command. */
+      showing_function_line = 1;
+      save_current = currently_executing_command;
+      result = run_debug_trap ();
+#if defined (DEBUGGER)
+      /* In debugging mode, if the DEBUG trap returns a non-zero status, we
+	 skip the command. */
+      if (debugging_mode == 0 || result == EXECUTION_SUCCESS)
+	{
+	  showing_function_line = 0;
+	  currently_executing_command = save_current;
+	  result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
+
+	  /* Run the RETURN trap in the function's context */
+	  save_current = currently_executing_command;
+	  run_return_trap ();
+	  currently_executing_command = save_current;
+	}
+#else
+      result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
+
+      save_current = currently_executing_command;
+      run_return_trap ();
+      currently_executing_command = save_current;
+#endif
+      showing_function_line = 0;
+    }
+
+  /* Restore BASH_ARGC and BASH_ARGV */
+  if (debugging_mode)
+    pop_args ();
+
+  if (subshell == 0)
+    run_unwind_frame ("function_calling");
+
+  funcnest--;
+#if defined (ARRAY_VARS)
+  /* These two variables cannot be unset, and cannot be affected by the
+     function. */
+  array_pop (bash_source_a);
+  array_pop (bash_lineno_a);
+
+  /* FUNCNAME can be unset, and so can potentially be changed by the
+     function. */
+  GET_ARRAY_FROM_VAR ("FUNCNAME", nfv, funcname_a);
+  if (nfv == funcname_v)
+    array_pop (funcname_a);
+#endif
+  
+  if (variable_context == 0 || this_shell_function == 0)
+    make_funcname_visible (0);
+
+  return (result);
+}
+
+/* A convenience routine for use by other parts of the shell to execute
+   a particular shell function. */
+int
+execute_shell_function (var, words)
+     SHELL_VAR *var;
+     WORD_LIST *words;
+{
+  int ret;
+  struct fd_bitmap *bitmap;
+
+  bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
+  begin_unwind_frame ("execute-shell-function");
+  add_unwind_protect (dispose_fd_bitmap, (char *)bitmap);
+      
+  ret = execute_function (var, words, 0, bitmap, 0, 0);
+
+  dispose_fd_bitmap (bitmap);
+  discard_unwind_frame ("execute-shell-function");
+
+  return ret;
+}
+
+/* Execute a shell builtin or function in a subshell environment.  This
+   routine does not return; it only calls exit().  If BUILTIN is non-null,
+   it points to a function to call to execute a shell builtin; otherwise
+   VAR points at the body of a function to execute.  WORDS is the arguments
+   to the command, REDIRECTS specifies redirections to perform before the
+   command is executed. */
+static void
+execute_subshell_builtin_or_function (words, redirects, builtin, var,
+				      pipe_in, pipe_out, async, fds_to_close,
+				      flags)
+     WORD_LIST *words;
+     REDIRECT *redirects;
+     sh_builtin_func_t *builtin;
+     SHELL_VAR *var;
+     int pipe_in, pipe_out, async;
+     struct fd_bitmap *fds_to_close;
+     int flags;
+{
+  int result, r;
+#if defined (JOB_CONTROL)
+  int jobs_hack;
+
+  jobs_hack = (builtin == jobs_builtin) &&
+		((subshell_environment & SUBSHELL_ASYNC) == 0 || pipe_out != NO_PIPE);
+#endif
+
+  /* A subshell is neither a login shell nor interactive. */
+  login_shell = interactive = 0;
+
+  subshell_environment = SUBSHELL_ASYNC;
+
+  maybe_make_export_env ();	/* XXX - is this needed? */
+
+#if defined (JOB_CONTROL)
+  /* Eradicate all traces of job control after we fork the subshell, so
+     all jobs begun by this subshell are in the same process group as
+     the shell itself. */
+
+  /* Allow the output of `jobs' to be piped. */
+  if (jobs_hack)
+    kill_current_pipeline ();
+  else
+    without_job_control ();
+
+  set_sigchld_handler ();
+#endif /* JOB_CONTROL */
+
+  set_sigint_handler ();
+
+  if (fds_to_close)
+    close_fd_bitmap (fds_to_close);
+
+  do_piping (pipe_in, pipe_out);
+
+  if (do_redirections (redirects, RX_ACTIVE) != 0)
+    exit (EXECUTION_FAILURE);
+
+  if (builtin)
+    {
+      /* Give builtins a place to jump back to on failure,
+	 so we don't go back up to main(). */
+      result = setjmp (top_level);
+
+      if (result == EXITPROG)
+	exit (last_command_exit_value);
+      else if (result)
+	exit (EXECUTION_FAILURE);
+      else
+	{
+	  r = execute_builtin (builtin, words, flags, 1);
+	  if (r == EX_USAGE)
+	    r = EX_BADUSAGE;
+	  exit (r);
+	}
+    }
+  else
+    exit (execute_function (var, words, flags, fds_to_close, async, 1));
+}
+
+/* Execute a builtin or function in the current shell context.  If BUILTIN
+   is non-null, it is the builtin command to execute, otherwise VAR points
+   to the body of a function.  WORDS are the command's arguments, REDIRECTS
+   are the redirections to perform.  FDS_TO_CLOSE is the usual bitmap of
+   file descriptors to close.
+
+   If BUILTIN is exec_builtin, the redirections specified in REDIRECTS are
+   not undone before this function returns. */
+static int
+execute_builtin_or_function (words, builtin, var, redirects,
+			     fds_to_close, flags)
+     WORD_LIST *words;
+     sh_builtin_func_t *builtin;
+     SHELL_VAR *var;
+     REDIRECT *redirects;
+     struct fd_bitmap *fds_to_close;
+     int flags;
+{
+  int result;
+  REDIRECT *saved_undo_list;
+  sh_builtin_func_t *saved_this_shell_builtin;
+
+  if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+    {
+      cleanup_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+      dispose_exec_redirects ();
+      return (EX_REDIRFAIL);	/* was EXECUTION_FAILURE */
+    }
+
+  saved_this_shell_builtin = this_shell_builtin;
+  saved_undo_list = redirection_undo_list;
+
+  /* Calling the "exec" builtin changes redirections forever. */
+  if (builtin == exec_builtin)
+    {
+      dispose_redirects (saved_undo_list);
+      saved_undo_list = exec_redirection_undo_list;
+      exec_redirection_undo_list = (REDIRECT *)NULL;
+    }
+  else
+    dispose_exec_redirects ();
+
+  if (saved_undo_list)
+    {
+      begin_unwind_frame ("saved redirects");
+      add_unwind_protect (cleanup_redirects, (char *)saved_undo_list);
+    }
+
+  redirection_undo_list = (REDIRECT *)NULL;
+
+  if (builtin)
+    result = execute_builtin (builtin, words, flags, 0);
+  else
+    result = execute_function (var, words, flags, fds_to_close, 0, 0);
+
+  /* We do this before undoing the effects of any redirections. */
+  if (ferror (stdout))
+    clearerr (stdout);  
+
+  /* If we are executing the `command' builtin, but this_shell_builtin is
+     set to `exec_builtin', we know that we have something like
+     `command exec [redirection]', since otherwise `exec' would have
+     overwritten the shell and we wouldn't get here.  In this case, we
+     want to behave as if the `command' builtin had not been specified
+     and preserve the redirections. */
+  if (builtin == command_builtin && this_shell_builtin == exec_builtin)
+    {
+      if (saved_undo_list)
+	dispose_redirects (saved_undo_list);
+      redirection_undo_list = exec_redirection_undo_list;
+      saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL;      
+      discard_unwind_frame ("saved_redirects");
+    }
+
+  if (saved_undo_list)
+    {
+      redirection_undo_list = saved_undo_list;
+      discard_unwind_frame ("saved redirects");
+    }
+
+  if (redirection_undo_list)
+    {
+      cleanup_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+    }
+
+  return (result);
+}
+
+void
+setup_async_signals ()
+{
+#if defined (__BEOS__)
+  set_signal_handler (SIGHUP, SIG_IGN);	/* they want csh-like behavior */
+#endif
+
+#if defined (JOB_CONTROL)
+  if (job_control == 0)
+#endif
+    {
+      set_signal_handler (SIGINT, SIG_IGN);
+      set_signal_ignored (SIGINT);
+      set_signal_handler (SIGQUIT, SIG_IGN);
+      set_signal_ignored (SIGQUIT);
+    }
+}
+
+/* Execute a simple command that is hopefully defined in a disk file
+   somewhere.
+
+   1) fork ()
+   2) connect pipes
+   3) look up the command
+   4) do redirections
+   5) execve ()
+   6) If the execve failed, see if the file has executable mode set.
+   If so, and it isn't a directory, then execute its contents as
+   a shell script.
+
+   Note that the filename hashing stuff has to take place up here,
+   in the parent.  This is probably why the Bourne style shells
+   don't handle it, since that would require them to go through
+   this gnarly hair, for no good reason.
+
+   NOTE: callers expect this to fork or exit(). */
+static void
+execute_disk_command (words, redirects, command_line, pipe_in, pipe_out,
+		      async, fds_to_close, cmdflags)
+     WORD_LIST *words;
+     REDIRECT *redirects;
+     char *command_line;
+     int pipe_in, pipe_out, async;
+     struct fd_bitmap *fds_to_close;
+     int cmdflags;
+{
+  char *pathname, *command, **args;
+  int nofork;
+  pid_t pid;
+
+  nofork = (cmdflags & CMD_NO_FORK);  /* Don't fork, just exec, if no pipes */
+  pathname = words->word->word;
+
+#if defined (RESTRICTED_SHELL)
+  command = (char *)NULL;
+  if (restricted && xstrchr (pathname, '/'))
+    {
+      internal_error (_("%s: restricted: cannot specify `/' in command names"),
+		    pathname);
+      last_command_exit_value = EXECUTION_FAILURE;
+
+      /* If we're not going to fork below, we must already be in a child
+         process or a context in which it's safe to call exit(2).  */
+      if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
+	exit (last_command_exit_value);
+      else
+	goto parent_return;
+    }
+#endif /* RESTRICTED_SHELL */
+
+  command = search_for_command (pathname);
+
+  if (command)
+    {
+      maybe_make_export_env ();
+      put_command_name_into_env (command);
+    }
+
+  /* We have to make the child before we check for the non-existence
+     of COMMAND, since we want the error messages to be redirected. */
+  /* If we can get away without forking and there are no pipes to deal with,
+     don't bother to fork, just directly exec the command. */
+  if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
+    pid = 0;
+  else
+    pid = make_child (savestring (command_line), async);
+
+  if (pid == 0)
+    {
+      int old_interactive;
+
+#if 0
+      /* This has been disabled for the time being. */
+#if !defined (ARG_MAX) || ARG_MAX >= 10240
+      if (posixly_correct == 0)
+	put_gnu_argv_flags_into_env ((long)getpid (), glob_argv_flags);
+#endif
+#endif
+
+      /* Cancel traps, in trap.c. */
+      restore_original_signals ();
+
+      /* restore_original_signals may have undone the work done
+	 by make_child to ensure that SIGINT and SIGQUIT are ignored
+	 in asynchronous children. */
+      if (async)
+	{
+	  if ((cmdflags & CMD_STDIN_REDIR) &&
+		pipe_in == NO_PIPE &&
+		(stdin_redirects (redirects) == 0))
+	    async_redirect_stdin ();
+	  setup_async_signals ();
+	}
+
+      /* This functionality is now provided by close-on-exec of the
+	 file descriptors manipulated by redirection and piping.
+	 Some file descriptors still need to be closed in all children
+	 because of the way bash does pipes; fds_to_close is a
+	 bitmap of all such file descriptors. */
+      if (fds_to_close)
+	close_fd_bitmap (fds_to_close);
+
+      do_piping (pipe_in, pipe_out);
+
+      old_interactive = interactive;
+      if (async)
+	interactive = 0;
+
+      subshell_environment = SUBSHELL_FORK;
+
+      if (redirects && (do_redirections (redirects, RX_ACTIVE) != 0))
+	{
+#if defined (PROCESS_SUBSTITUTION)
+	  /* Try to remove named pipes that may have been created as the
+	     result of redirections. */
+	  unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+	  exit (EXECUTION_FAILURE);
+	}
+
+      if (async)
+	interactive = old_interactive;
+
+      if (command == 0)
+	{
+	  internal_error (_("%s: command not found"), pathname);
+	  exit (EX_NOTFOUND);	/* Posix.2 says the exit status is 127 */
+	}
+
+      /* Execve expects the command name to be in args[0].  So we
+	 leave it there, in the same format that the user used to
+	 type it in. */
+      args = strvec_from_word_list (words, 0, 0, (int *)NULL);
+      exit (shell_execve (command, args, export_env));
+    }
+  else
+    {
+parent_return:
+      /* Make sure that the pipes are closed in the parent. */
+      close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+      unlink_fifo_list ();
+#endif
+      FREE (command);
+    }
+}
+
+/* CPP defines to decide whether a particular index into the #! line
+   corresponds to a valid interpreter name or argument character, or
+   whitespace.  The MSDOS define is to allow \r to be treated the same
+   as \n. */
+
+#if !defined (MSDOS)
+#  define STRINGCHAR(ind) \
+    (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n')
+#  define WHITECHAR(ind) \
+    (ind < sample_len && whitespace (sample[ind]))
+#else	/* MSDOS */
+#  define STRINGCHAR(ind) \
+    (ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n' && sample[ind] != '\r')
+#  define WHITECHAR(ind) \
+    (ind < sample_len && whitespace (sample[ind]))
+#endif	/* MSDOS */
+
+static char *
+getinterp (sample, sample_len, endp)
+     char *sample;
+     int sample_len, *endp;
+{
+  register int i;
+  char *execname;
+  int start;
+
+  /* Find the name of the interpreter to exec. */
+  for (i = 2; i < sample_len && whitespace (sample[i]); i++)
+    ;
+
+  for (start = i; STRINGCHAR(i); i++)
+    ;
+
+  execname = substring (sample, start, i);
+
+  if (endp)
+    *endp = i;
+  return execname;
+}
+
+#if !defined (HAVE_HASH_BANG_EXEC)
+/* If the operating system on which we're running does not handle
+   the #! executable format, then help out.  SAMPLE is the text read
+   from the file, SAMPLE_LEN characters.  COMMAND is the name of
+   the script; it and ARGS, the arguments given by the user, will
+   become arguments to the specified interpreter.  ENV is the environment
+   to pass to the interpreter.
+
+   The word immediately following the #! is the interpreter to execute.
+   A single argument to the interpreter is allowed. */
+
+static int
+execute_shell_script (sample, sample_len, command, args, env)
+     char *sample;
+     int sample_len;
+     char *command;
+     char **args, **env;
+{
+  char *execname, *firstarg;
+  int i, start, size_increment, larry;
+
+  /* Find the name of the interpreter to exec. */
+  execname = getinterp (sample, sample_len, &i);
+  size_increment = 1;
+
+  /* Now the argument, if any. */
+  for (firstarg = (char *)NULL, start = i; WHITECHAR(i); i++)
+    ;
+
+  /* If there is more text on the line, then it is an argument for the
+     interpreter. */
+
+  if (STRINGCHAR(i))  
+    {
+      for (start = i; STRINGCHAR(i); i++)
+	;
+      firstarg = substring ((char *)sample, start, i);
+      size_increment = 2;
+    }
+
+  larry = strvec_len (args) + size_increment;
+  args = strvec_resize (args, larry + 1);
+
+  for (i = larry - 1; i; i--)
+    args[i] = args[i - size_increment];
+
+  args[0] = execname;
+  if (firstarg)
+    {
+      args[1] = firstarg;
+      args[2] = command;
+    }
+  else
+    args[1] = command;
+
+  args[larry] = (char *)NULL;
+
+  return (shell_execve (execname, args, env));
+}
+#undef STRINGCHAR
+#undef WHITECHAR
+
+#endif /* !HAVE_HASH_BANG_EXEC */
+
+static void
+initialize_subshell ()
+{
+#if defined (ALIAS)
+  /* Forget about any aliases that we knew of.  We are in a subshell. */
+  delete_all_aliases ();
+#endif /* ALIAS */
+
+#if defined (HISTORY)
+  /* Forget about the history lines we have read.  This is a non-interactive
+     subshell. */
+  history_lines_this_session = 0;
+#endif
+
+#if defined (JOB_CONTROL)
+  /* Forget about the way job control was working. We are in a subshell. */
+  without_job_control ();
+  set_sigchld_handler ();
+  init_job_stats ();
+#endif /* JOB_CONTROL */
+
+  /* Reset the values of the shell flags and options. */
+  reset_shell_flags ();
+  reset_shell_options ();
+  reset_shopt_options ();
+
+  /* Zero out builtin_env, since this could be a shell script run from a
+     sourced file with a temporary environment supplied to the `source/.'
+     builtin.  Such variables are not supposed to be exported (empirical
+     testing with sh and ksh).  Just throw it away; don't worry about a
+     memory leak. */
+  if (vc_isbltnenv (shell_variables))
+    shell_variables = shell_variables->down;
+
+  clear_unwind_protect_list (0);
+
+  /* We're no longer inside a shell function. */
+  variable_context = return_catch_flag = 0;
+
+  /* If we're not interactive, close the file descriptor from which we're
+     reading the current shell script. */
+  if (interactive_shell == 0)
+    unset_bash_input (0);
+}
+
+#if defined (HAVE_SETOSTYPE) && defined (_POSIX_SOURCE)
+#  define SETOSTYPE(x)	__setostype(x)
+#else
+#  define SETOSTYPE(x)
+#endif
+
+#define READ_SAMPLE_BUF(file, buf, len) \
+  do \
+    { \
+      fd = open(file, O_RDONLY); \
+      if (fd >= 0) \
+	{ \
+	  len = read (fd, buf, 80); \
+	  close (fd); \
+	} \
+      else \
+	len = -1; \
+    } \
+  while (0)
+      
+/* Call execve (), handling interpreting shell scripts, and handling
+   exec failures. */
+int
+shell_execve (command, args, env)
+     char *command;
+     char **args, **env;
+{
+  struct stat finfo;
+  int larray, i, fd;
+  char sample[80];
+  int sample_len;
+
+  SETOSTYPE (0);		/* Some systems use for USG/POSIX semantics */
+  execve (command, args, env);
+  i = errno;			/* error from execve() */
+  SETOSTYPE (1);
+
+  /* If we get to this point, then start checking out the file.
+     Maybe it is something we can hack ourselves. */
+  if (i != ENOEXEC)
+    {
+      if ((stat (command, &finfo) == 0) && (S_ISDIR (finfo.st_mode)))
+	internal_error (_("%s: is a directory"), command);
+      else if (executable_file (command) == 0)
+	{
+	  errno = i;
+	  file_error (command);
+	}
+      /* errors not involving the path argument to execve. */
+      else if (i == E2BIG || i == ENOMEM)
+	{
+	  errno = i;
+	  file_error (command);
+	}
+      else
+	{
+	  /* The file has the execute bits set, but the kernel refuses to
+	     run it for some reason.  See why. */
+#if defined (HAVE_HASH_BANG_EXEC)
+	  READ_SAMPLE_BUF (command, sample, sample_len);
+	  if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
+	    {
+	      char *interp;
+	      int ilen;
+
+	      interp = getinterp (sample, sample_len, (int *)NULL);
+	      ilen = strlen (interp);
+	      errno = i;
+	      if (interp[ilen - 1] == '\r')
+		{
+		  interp = xrealloc (interp, ilen + 2);
+		  interp[ilen - 1] = '^';
+		  interp[ilen] = 'M';
+		  interp[ilen + 1] = '\0';
+		}
+	      sys_error (_("%s: %s: bad interpreter"), command, interp ? interp : "");
+	      FREE (interp);
+	      return (EX_NOEXEC);
+	    }
+#endif
+	  errno = i;
+	  file_error (command);
+	}
+      return ((i == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);	/* XXX Posix.2 says that exit status is 126 */
+    }
+
+  /* This file is executable.
+     If it begins with #!, then help out people with losing operating
+     systems.  Otherwise, check to see if it is a binary file by seeing
+     if the contents of the first line (or up to 80 characters) are in the
+     ASCII set.  If it's a text file, execute the contents as shell commands,
+     otherwise return 126 (EX_BINARY_FILE). */
+  READ_SAMPLE_BUF (command, sample, sample_len);
+
+  if (sample_len == 0)
+    return (EXECUTION_SUCCESS);
+
+  /* Is this supposed to be an executable script?
+     If so, the format of the line is "#! interpreter [argument]".
+     A single argument is allowed.  The BSD kernel restricts
+     the length of the entire line to 32 characters (32 bytes
+     being the size of the BSD exec header), but we allow 80
+     characters. */
+  if (sample_len > 0)
+    {
+#if !defined (HAVE_HASH_BANG_EXEC)
+      if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
+	return (execute_shell_script (sample, sample_len, command, args, env));
+      else
+#endif
+      if (check_binary_file (sample, sample_len))
+	{
+	  internal_error (_("%s: cannot execute binary file"), command);
+	  return (EX_BINARY_FILE);
+	}
+    }
+
+  /* We have committed to attempting to execute the contents of this file
+     as shell commands. */
+
+  initialize_subshell ();
+
+  set_sigint_handler ();
+
+  /* Insert the name of this shell into the argument list. */
+  larray = strvec_len (args) + 1;
+  args = strvec_resize (args, larray + 1);
+
+  for (i = larray - 1; i; i--)
+    args[i] = args[i - 1];
+
+  args[0] = shell_name;
+  args[1] = command;
+  args[larray] = (char *)NULL;
+
+  if (args[0][0] == '-')
+    args[0]++;
+
+#if defined (RESTRICTED_SHELL)
+  if (restricted)
+    change_flag ('r', FLAG_OFF);
+#endif
+
+  if (subshell_argv)
+    {
+      /* Can't free subshell_argv[0]; that is shell_name. */
+      for (i = 1; i < subshell_argc; i++)
+	free (subshell_argv[i]);
+      free (subshell_argv);
+    }
+
+  dispose_command (currently_executing_command);	/* XXX */
+  currently_executing_command = (COMMAND *)NULL;
+
+  subshell_argc = larray;
+  subshell_argv = args;
+  subshell_envp = env;
+
+  unbind_args ();	/* remove the positional parameters */
+
+  longjmp (subshell_top_level, 1);
+  /*NOTREACHED*/
+}
+
+static int
+execute_intern_function (name, function)
+     WORD_DESC *name;
+     COMMAND *function;
+{
+  SHELL_VAR *var;
+
+  if (check_identifier (name, posixly_correct) == 0)
+    {
+      if (posixly_correct && interactive_shell == 0)
+	{
+	  last_command_exit_value = EX_USAGE;
+	  jump_to_top_level (ERREXIT);
+	}
+      return (EXECUTION_FAILURE);
+    }
+
+  var = find_function (name->word);
+  if (var && (readonly_p (var) || noassign_p (var)))
+    {
+      if (readonly_p (var))
+	internal_error (_("%s: readonly function"), var->name);
+      return (EXECUTION_FAILURE);
+    }
+
+  bind_function (name->word, function);
+  return (EXECUTION_SUCCESS);
+}
+
+#if defined (INCLUDE_UNUSED)
+#if defined (PROCESS_SUBSTITUTION)
+void
+close_all_files ()
+{
+  register int i, fd_table_size;
+
+  fd_table_size = getdtablesize ();
+  if (fd_table_size > 256)	/* clamp to a reasonable value */
+    fd_table_size = 256;
+
+  for (i = 3; i < fd_table_size; i++)
+    close (i);
+}
+#endif /* PROCESS_SUBSTITUTION */
+#endif
+
+static void
+close_pipes (in, out)
+     int in, out;
+{
+  if (in >= 0)
+    close (in);
+  if (out >= 0)
+    close (out);
+}
+
+static void
+dup_error (oldd, newd)
+     int oldd, newd;
+{
+  sys_error (_("cannot duplicate fd %d to fd %d"), oldd, newd);
+}
+
+/* Redirect input and output to be from and to the specified pipes.
+   NO_PIPE and REDIRECT_BOTH are handled correctly. */
+static void
+do_piping (pipe_in, pipe_out)
+     int pipe_in, pipe_out;
+{
+  if (pipe_in != NO_PIPE)
+    {
+      if (dup2 (pipe_in, 0) < 0)
+	dup_error (pipe_in, 0);
+      if (pipe_in > 0)
+	close (pipe_in);
+    }
+  if (pipe_out != NO_PIPE)
+    {
+      if (pipe_out != REDIRECT_BOTH)
+	{
+	  if (dup2 (pipe_out, 1) < 0)
+	    dup_error (pipe_out, 1);
+	  if (pipe_out == 0 || pipe_out > 1)
+	    close (pipe_out);
+	}
+      else
+	{
+	  if (dup2 (1, 2) < 0)
+	    dup_error (1, 2);
+	}
+    }
+}