Adding upstream version 5.2.15.upstream/5.2.15upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 6229 insertions, 0 deletions

diff --git a/execute_cmd.c b/execute_cmd.c
new file mode 100644
index 0000000..41d3cf8
--- /dev/null
+++ b/execute_cmd.c
@@ -0,0 +1,6229 @@
+/* execute_cmd.c -- Execute a COMMAND structure. */
+
+/* Copyright (C) 1987-2022 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#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>
+#if defined (HAVE_SYS_PARAM_H)
+#  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
+
+#define NEED_FPURGE_DECL
+#define NEED_SH_SETLINEBUF_DECL
+
+#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 "parser.h"
+#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 "builtins/getopt.h"
+
+#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
+
+#if defined (HAVE_MBSTR_H) && defined (HAVE_MBSCHR)
+#  include <mbstr.h>		/* mbschr */
+#endif
+
+extern int command_string_index;
+extern char *the_printed_command;
+extern time_t shell_start_time;
+#if defined (HAVE_GETTIMEOFDAY)
+extern struct timeval shellstart;
+#endif
+#if 0
+extern char *glob_argv_flags;
+#endif
+
+extern int close PARAMS((int));
+
+/* Static functions defined and used in this file. */
+static void close_pipes PARAMS((int, int));
+static void do_piping PARAMS((int, int));
+static void bind_lastarg PARAMS((char *));
+static int shell_control_structure PARAMS((enum command_type));
+static void cleanup_redirects PARAMS((REDIRECT *));
+
+#if defined (JOB_CONTROL)
+static int restore_signal_mask PARAMS((sigset_t *));
+#endif
+
+static int builtin_status PARAMS((int));
+
+static int execute_for_command PARAMS((FOR_COM *));
+#if defined (SELECT_COMMAND)
+static int displen PARAMS((const char *));
+static int print_index_and_element PARAMS((int, int, WORD_LIST *));
+static void indent PARAMS((int, int));
+static void print_select_list PARAMS((WORD_LIST *, int, int, int));
+static char *select_query PARAMS((WORD_LIST *, int, char *, int));
+static int execute_select_command PARAMS((SELECT_COM *));
+#endif
+#if defined (DPAREN_ARITHMETIC)
+static int execute_arith_command PARAMS((ARITH_COM *));
+#endif
+#if defined (COND_COMMAND)
+static int execute_cond_node PARAMS((COND_COM *));
+static int execute_cond_command PARAMS((COND_COM *));
+#endif
+#if defined (COMMAND_TIMING)
+static int mkfmt PARAMS((char *, int, int, time_t, int));
+static void print_formatted_time PARAMS((FILE *, char *,
+				      time_t, int, time_t, int,
+				      time_t, int, int));
+static int time_command PARAMS((COMMAND *, int, int, int, struct fd_bitmap *));
+#endif
+#if defined (ARITH_FOR_COMMAND)
+static intmax_t eval_arith_for_expr PARAMS((WORD_LIST *, int *));
+static int execute_arith_for_command PARAMS((ARITH_FOR_COM *));
+#endif
+static int execute_case_command PARAMS((CASE_COM *));
+static int execute_while_command PARAMS((WHILE_COM *));
+static int execute_until_command PARAMS((WHILE_COM *));
+static int execute_while_or_until PARAMS((WHILE_COM *, int));
+static int execute_if_command PARAMS((IF_COM *));
+static int execute_null_command PARAMS((REDIRECT *, int, int, int));
+static void fix_assignment_words PARAMS((WORD_LIST *));
+static void fix_arrayref_words PARAMS((WORD_LIST *));
+static int execute_simple_command PARAMS((SIMPLE_COM *, int, int, int, struct fd_bitmap *));
+static int execute_builtin PARAMS((sh_builtin_func_t *, WORD_LIST *, int, int));
+static int execute_function PARAMS((SHELL_VAR *, WORD_LIST *, int, struct fd_bitmap *, int, int));
+static int execute_builtin_or_function PARAMS((WORD_LIST *, sh_builtin_func_t *,
+					    SHELL_VAR *,
+					    REDIRECT *, struct fd_bitmap *, int));
+static void execute_subshell_builtin_or_function PARAMS((WORD_LIST *, REDIRECT *,
+						      sh_builtin_func_t *,
+						      SHELL_VAR *,
+						      int, int, int,
+						      struct fd_bitmap *,
+						      int));
+static int execute_disk_command PARAMS((WORD_LIST *, REDIRECT *, char *,
+				      int, int, int, struct fd_bitmap *, int));
+
+static char *getinterp PARAMS((char *, int, int *));
+static void initialize_subshell PARAMS((void));
+static int execute_in_subshell PARAMS((COMMAND *, int, int, int, struct fd_bitmap *));
+#if defined (COPROCESS_SUPPORT)
+static void coproc_setstatus PARAMS((struct coproc *, int));
+static int execute_coproc PARAMS((COMMAND *, int, int, struct fd_bitmap *));
+#endif
+
+static int execute_pipeline PARAMS((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_connection PARAMS((COMMAND *, int, int, int, struct fd_bitmap *));
+
+static int execute_intern_function PARAMS((WORD_DESC *, FUNCTION_DEF *));
+
+/* 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;
+
+/* 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. */
+volatile 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;
+
+/* Are we currently ignoring the -e option for the duration of a builtin's
+   execution? */
+int builtin_ignoring_errexit = 0;
+
+/* 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;
+
+/* When greater than zero, value is the `level' of builtins we are
+   currently executing (e.g. `eval echo a' would have it set to 2). */
+int executing_builtin = 0;
+
+/* Non-zero if we are executing a command list (a;b;c, etc.) */
+int executing_list = 0;
+
+/* Non-zero if failing commands in a command substitution should not exit the
+   shell even if -e is set.  Used to pass the CMD_IGNORE_RETURN flag down to
+   commands run in command substitutions by parse_and_execute. */
+int comsub_ignore_return = 0;
+
+/* 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;
+
+int executing_command_builtin = 0;
+
+struct stat SB;		/* used for debugging */
+
+static int special_builtin_failed;
+
+static COMMAND *currently_executing_command;
+
+/* The line number that the currently executing function starts on. */
+static int function_line_number;
+
+/* 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;
+
+static int connection_count;
+
+/* $LINENO ($BASH_LINENO) for use by an ERR trap.  Global so parse_and_execute
+   can save and restore it. */
+int line_number_for_err_trap;
+
+/* A convenience macro to avoid resetting line_number_for_err_trap while
+   running the ERR trap. */
+#define SET_LINE_NUMBER(v) \
+do { \
+  line_number = v; \
+  if (signal_in_progress (ERROR_TRAP) == 0 && running_trap != (ERROR_TRAP + 1)) \
+    line_number_for_err_trap = line_number; \
+} while (0)
+
+/* This can't be in executing_line_number() because that's used for LINENO
+   and we want LINENO to reflect the line number of commands run during
+   the ERR trap. Right now this is only used to push to BASH_LINENO. */
+#define GET_LINE_NUMBER() \
+  (signal_in_progress (ERROR_TRAP) && running_trap == ERROR_TRAP+1) \
+    ? line_number_for_err_trap \
+    : executing_line_number ()
+
+/* A sort of function nesting level counter */
+int funcnest = 0;
+int funcnest_max = 0;
+
+int evalnest = 0;
+int evalnest_max = EVALNEST_MAX;
+
+int sourcenest = 0;
+int sourcenest_max = SOURCENEST_MAX;
+
+volatile int from_return_trap = 0;
+
+int lastpipe_opt = 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)
+      if (currently_executing_command->type == cm_arith)
+	return currently_executing_command->value.Arith->line;
+#endif
+#if defined (ARITH_FOR_COMMAND)
+      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 && executing_list == 0)
+    unlink_fifo_list ();
+#endif /* PROCESS_SUBSTITUTION */
+
+  QUIT;
+  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);
+}
+
+void
+undo_partial_redirects ()
+{
+  if (redirection_undo_list)
+    {
+      cleanup_redirects (redirection_undo_list);
+      redirection_undo_list = (REDIRECT *)NULL;
+    }
+}
+
+#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;
+    }
+}
+
+void
+dispose_partial_redirects ()
+{
+  if (redirection_undo_list)
+    {
+      dispose_redirects (redirection_undo_list);
+      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 (void)
+{
+  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
+
+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 asynchronously.
+   COMMAND is exactly what read_command () places into GLOBAL_COMMAND.
+   ASYNCHRONOUS, 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, user_subshell, invert, ignore_return, was_error_trap, fork_flags;
+  REDIRECT *my_undo_list, *exec_undo_list;
+  char *tcmd;
+  volatile int save_line_number;
+#if defined (PROCESS_SUBSTITUTION)
+  volatile int ofifo, nfifo, osize, saved_fifo;
+  volatile void *ofifo_list;
+#endif
+
+  if (breaking || continuing)
+    return (last_command_exit_value);
+  if (read_but_dont_execute)
+    return (last_command_exit_value);
+  if (command == 0)
+    return (EXECUTION_SUCCESS);
+
+  QUIT;
+  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 defined (COPROCESS_SUPPORT)
+  if (command->type == cm_coproc)
+    return (last_command_exit_value = execute_coproc (command, pipe_in, pipe_out, fds_to_close));
+#endif
+
+  user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
+
+#if defined (TIME_BEFORE_SUBSHELL)
+  if ((command->flags & CMD_TIME_PIPELINE) && user_subshell && asynchronous == 0)
+    {
+      command->flags |= CMD_FORCE_SUBSHELL;
+      exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+      currently_executing_command = (COMMAND *)NULL;
+      return (exec_result);
+    }
+#endif
+
+  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;
+      int s;
+      char *p;
+
+      /* Fork a subshell, turn off the subshell bit, turn off job
+	 control and call execute_command () on the command again. */
+      save_line_number = line_number;
+      if (command->type == cm_subshell)
+	SET_LINE_NUMBER (command->value.Subshell->line);	/* XXX - save value? */
+	/* Otherwise we defer setting line_number */
+      tcmd = make_command_string (command);
+      fork_flags = asynchronous ? FORK_ASYNC : 0;
+      paren_pid = make_child (p = savestring (tcmd), fork_flags);
+
+      if (user_subshell && signal_is_trapped (ERROR_TRAP) && 
+	  signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+	{
+	  FREE (the_printed_command_except_trap);
+	  the_printed_command_except_trap = savestring (the_printed_command);
+	}
+
+      if (paren_pid == 0)
+        {
+#if defined (JOB_CONTROL)
+	  FREE (p);		/* child doesn't use pointer */
+#endif
+	  /* We want to run the exit trap for forced {} subshells, and we
+	     want to note this before execute_in_subshell modifies the
+	     COMMAND struct.  Need to keep in mind that execute_in_subshell
+	     runs the exit trap for () subshells itself. */
+	  /* This handles { command; } & */
+	  s = user_subshell == 0 && command->type == cm_group && pipe_in == NO_PIPE && pipe_out == NO_PIPE && asynchronous;
+	  /* run exit trap for : | { ...; } and { ...; } | : */
+	  /* run exit trap for : | ( ...; ) and ( ...; ) | : */
+	  s += user_subshell == 0 && command->type == cm_group && (pipe_in != NO_PIPE || pipe_out != NO_PIPE) && asynchronous == 0;
+
+	  last_command_exit_value = execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+	  if (s)
+	    subshell_exit (last_command_exit_value);
+	  else
+	    sh_exit (last_command_exit_value);
+	  /* NOTREACHED */
+        }
+      else
+	{
+	  close_pipes (pipe_in, pipe_out);
+
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+	  if (variable_context == 0)	/* wait until shell function completes */
+	    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);
+
+	  line_number = save_line_number;
+
+	  if (asynchronous == 0)
+	    {
+	      was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+	      invert = (command->flags & CMD_INVERT_RETURN) != 0;
+	      ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+	      exec_result = wait_for (paren_pid, 0);
+
+	      /* If we have to, invert the return value. */
+	      if (invert)
+		exec_result = ((exec_result == EXECUTION_SUCCESS)
+				? EXECUTION_FAILURE
+				: EXECUTION_SUCCESS);
+
+	      last_command_exit_value = exec_result;
+	      if (user_subshell && was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+		{
+		  save_line_number = line_number;
+		  line_number = line_number_for_err_trap;
+		  run_error_trap ();
+		  line_number = save_line_number;
+		}
+
+	      if (user_subshell && ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+		{
+		  run_pending_traps ();
+		  jump_to_top_level (ERREXIT);
+		}
+
+	      return (last_command_exit_value);
+	    }
+	  else
+	    {
+	      DESCRIBE_PID (paren_pid);
+
+	      run_pending_traps ();
+
+	      /* Posix 2013 2.9.3.1: "the exit status of an asynchronous list
+		 shall be zero." */
+	      last_command_exit_value = 0;
+	      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);
+
+#if defined (PROCESS_SUBSTITUTION)
+#  if !defined (HAVE_DEV_FD)
+  reap_procsubs ();
+#  endif
+
+  /* XXX - also if sourcelevel != 0? */
+  if (variable_context != 0 || executing_list)
+    {
+      ofifo = num_fifos ();
+      ofifo_list = copy_fifo_list ((int *)&osize);
+      begin_unwind_frame ("internal_fifos");
+      if (ofifo_list)
+	add_unwind_protect (xfree, ofifo_list);
+      saved_fifo = 1;
+    }
+  else
+    saved_fifo = 0;
+#endif
+
+  /* Handle WHILE FOR CASE etc. with redirections.  (Also '&' input
+     redirection.)  */
+  was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+  ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+  if (do_redirections (command->redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+    {
+      undo_partial_redirects ();
+      dispose_exec_redirects ();
+#if defined (PROCESS_SUBSTITUTION)
+      if (saved_fifo)
+	{
+	  free ((void *)ofifo_list);
+          discard_unwind_frame ("internal_fifos");
+	}
+#endif
+
+      /* Handle redirection error as command failure if errexit set. */
+      last_command_exit_value = EXECUTION_FAILURE;
+      if (ignore_return == 0 && invert == 0 && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
+	{
+	  if (was_error_trap)
+	    {
+	      save_line_number = line_number;
+	      line_number = line_number_for_err_trap;
+	      run_error_trap ();
+	      line_number = save_line_number;
+	    }
+	  if (exit_immediately_on_error)
+	    {	  
+	      run_pending_traps ();
+	      jump_to_top_level (ERREXIT);
+	    }
+	}
+      return (last_command_exit_value);
+    }
+
+  my_undo_list = redirection_undo_list;
+  redirection_undo_list = (REDIRECT *)NULL;
+
+  exec_undo_list = exec_redirection_undo_list;
+  exec_redirection_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);
+
+  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
+	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;
+
+	SET_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.  Don't worry about
+	   whether or not last_made_pid == last_pid; already_making_children
+	   tells us whether or not there are unwaited-for children to wait
+	   for and reap. */
+	if (already_making_children && pipe_out == NO_PIPE)
+	  {
+	    stop_pipeline (asynchronous, (COMMAND *)NULL);
+
+	    if (asynchronous)
+	      {
+		DESCRIBE_PID (last_made_pid);
+		exec_result = EXECUTION_SUCCESS;
+		invert = 0;		/* async commands always succeed */
+	      }
+	    else
+#if !defined (JOB_CONTROL)
+	      /* Do not wait for asynchronous processes started from
+		 startup files. */
+	    if (last_made_pid != NO_PID && last_made_pid != last_asynchronous_pid)
+#else
+	    if (last_made_pid != NO_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, 0);
+	  }
+      }
+
+      /* 2009/02/13 -- pipeline failure is processed elsewhere.  This handles
+	 only the failure of a simple command. We don't want to run the error
+	 trap if the command run by the `command' builtin fails; we want to
+	 defer that until the command builtin itself returns failure. */
+      /* 2020/07/14 -- this changes with how the command builtin is handled */ 
+      if (was_error_trap && ignore_return == 0 && invert == 0 &&
+	    pipe_in == NO_PIPE && pipe_out == NO_PIPE &&
+	    (command->value.Simple->flags & CMD_COMMAND_BUILTIN) == 0 &&
+	    exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  line_number = line_number_for_err_trap;
+	  run_error_trap ();
+	  line_number = save_line_number;
+	}
+
+      if (ignore_return == 0 && invert == 0 &&
+	  ((posixly_correct && interactive == 0 && special_builtin_failed) ||
+	   (exit_immediately_on_error && pipe_in == NO_PIPE && pipe_out == NO_PIPE && exec_result != EXECUTION_SUCCESS)))
+	{
+	  last_command_exit_value = exec_result;
+	  run_pending_traps ();
+
+	  /* Undo redirections before running exit trap on the way out of
+	     set -e. Report by Mark Farrell 5/19/2014 */
+	  if (exit_immediately_on_error && signal_is_trapped (0) &&
+		unwind_protect_tag_on_stack ("saved-redirects"))
+	    run_unwind_frame ("saved-redirects");
+
+	  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);
+      if (asynchronous)
+	invert = 0;		/* XXX */
+
+      break;
+
+#if defined (DPAREN_ARITHMETIC)
+    case cm_arith:
+#endif
+#if defined (COND_COMMAND)
+    case cm_cond:
+#endif
+    case cm_function_def:
+      was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+#if defined (DPAREN_ARITHMETIC)
+      if (ignore_return && command->type == cm_arith)
+	command->value.Arith->flags |= CMD_IGNORE_RETURN;
+#endif
+#if defined (COND_COMMAND)
+      if (ignore_return && command->type == cm_cond)
+	command->value.Cond->flags |= CMD_IGNORE_RETURN;
+#endif
+
+      line_number_for_err_trap = save_line_number = line_number;	/* XXX */
+#if defined (DPAREN_ARITHMETIC)
+      if (command->type == cm_arith)
+	exec_result = execute_arith_command (command->value.Arith);
+      else
+#endif
+#if defined (COND_COMMAND)
+      if (command->type == cm_cond)
+	exec_result = execute_cond_command (command->value.Cond);
+      else
+#endif
+      if (command->type == cm_function_def)
+	exec_result = execute_intern_function (command->value.Function_def->name,
+					       command->value.Function_def);
+      line_number = save_line_number;
+
+      if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  save_line_number = line_number;
+	  line_number = line_number_for_err_trap;
+	  run_error_trap ();
+	  line_number = save_line_number;
+	}
+
+      if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  run_pending_traps ();
+	  jump_to_top_level (ERREXIT);
+	}
+
+      break;
+
+    default:
+      command_error ("execute_command", CMDERR_BADTYPE, command->type, 0);
+    }
+
+  if (my_undo_list)
+    cleanup_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");
+
+#if defined (PROCESS_SUBSTITUTION)
+  if (saved_fifo)
+    {
+      nfifo = num_fifos ();
+      if (nfifo > ofifo)
+	close_new_fifos ((void *)ofifo_list, osize);
+      free ((void *)ofifo_list);
+      discard_unwind_frame ("internal_fifos");
+    }
+#endif
+
+  /* Invert the return value if we have to */
+  if (invert)
+    exec_result = (exec_result == EXECUTION_SUCCESS)
+		    ? EXECUTION_FAILURE
+		    : EXECUTION_SUCCESS;
+
+#if defined (DPAREN_ARITHMETIC) || defined (COND_COMMAND)
+  /* This is where we set PIPESTATUS from the exit status of the appropriate
+     compound commands (the ones that look enough like simple commands to
+     cause confusion).  We might be able to optimize by not doing this if
+     subshell_environment != 0. */
+  switch (command->type)
+    {
+#  if defined (DPAREN_ARITHMETIC)
+    case cm_arith:
+#  endif
+#  if defined (COND_COMMAND)
+    case cm_cond:
+#  endif
+      set_pipestatus_from_exit (exec_result);
+      break;
+    default:
+      break;
+    }
+#endif
+
+  last_command_exit_value = exec_result;
+  run_pending_traps ();
+  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 PARAMS((struct timeval *, struct timeval *, struct timeval *));
+extern struct timeval *addtimeval PARAMS((struct timeval *, struct timeval *, struct timeval *));
+extern int timeval_to_cpu PARAMS((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 const 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++] = locale_decpoint ();
+      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 0
+	  /* clamp CPU usage at 100% */
+	  if (cpu > 10000)
+	    cpu = 10000;
+#endif
+	  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, nullcmd, code;
+  time_t rs, us, ss;
+  int rsf, usf, ssf;
+  int cpu;
+  char *time_format;
+  volatile procenv_t save_top_level;
+  volatile int old_subshell;
+
+#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
+
+  old_subshell = subshell_environment;
+  posix_time = command && (command->flags & CMD_TIME_POSIX);
+
+  nullcmd = (command == 0) || (command->type == cm_simple && command->value.Simple->words == 0 && command->value.Simple->redirects == 0);
+  if (posixly_correct && nullcmd)
+    {
+#if defined (HAVE_GETRUSAGE)
+      selfb.ru_utime.tv_sec = kidsb.ru_utime.tv_sec = selfb.ru_stime.tv_sec = kidsb.ru_stime.tv_sec = 0;
+      selfb.ru_utime.tv_usec = kidsb.ru_utime.tv_usec = selfb.ru_stime.tv_usec = kidsb.ru_stime.tv_usec = 0;
+      before = shellstart;
+#else
+      before.tms_utime = before.tms_stime = before.tms_cutime = before.tms_cstime = 0;
+      tbefore = shell_start_time;
+#endif
+    }
+
+  old_flags = command->flags;
+  COPY_PROCENV (top_level, save_top_level);
+  command->flags &= ~(CMD_TIME_PIPELINE|CMD_TIME_POSIX);
+  code = setjmp_nosigs (top_level);
+  if (code == NOT_JUMPED)
+    rv = execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+  COPY_PROCENV (save_top_level, top_level);
+
+  command->flags = old_flags;
+
+  /* If we're jumping in a different subshell environment than we started,
+     don't bother printing timing stats, just keep longjmping back to the
+     original top level. */
+  if (code != NOT_JUMPED && subshell_environment && subshell_environment != old_subshell)
+    sh_longjmp (top_level, code);
+
+  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)
+    {
+      if (posixly_correct && nullcmd)
+	time_format = "user\t%2lU\nsys\t%2lS";
+      else
+	time_format = BASH_TIMEFORMAT;
+    }
+
+  if (time_format && *time_format)
+    print_formatted_time (stderr, time_format, rs, rsf, us, usf, ss, ssf, cpu);
+
+  if (code)
+    sh_longjmp (top_level, code);
+
+  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;
+{
+  volatile int user_subshell, user_coproc, invert;
+  int return_code, function_value, should_redir_stdin, ois, result;
+  volatile COMMAND *tcom;
+
+  USE_VAR(user_subshell);
+  USE_VAR(user_coproc);
+  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);
+  user_coproc = command->type == cm_coproc;
+
+  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.
+     XXX - asynchronous used to be set to 0 in this block, but that
+     means that setup_async_signals was never run.  Now it's set to
+     0 after subshell_environment is set appropriately and setup_async_signals
+     is run.
+
+     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 = expaliases_flag = 0;
+    }
+
+  /* Subshells are neither login nor interactive. */
+  login_shell = interactive = 0;
+
+  /* And we're no longer in a loop. See Posix interp 842 (we are not in the
+     "same execution environment"). */
+  if (shell_compatibility_level > 44)
+    loop_level = 0;
+
+  if (user_subshell)
+    {
+      subshell_environment = SUBSHELL_PAREN;	/* XXX */
+      if (asynchronous)
+	subshell_environment |= SUBSHELL_ASYNC;
+    }
+  else
+    {
+      subshell_environment = 0;			/* XXX */
+      if (asynchronous)
+	subshell_environment |= SUBSHELL_ASYNC;
+      if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+	subshell_environment |= SUBSHELL_PIPE;
+      if (user_coproc)
+	subshell_environment |= SUBSHELL_COPROC;
+    }
+
+  QUIT;
+  CHECK_TERMSIG;
+
+  reset_terminating_signals ();		/* in sig.c */
+  /* Cancel traps, in trap.c. */
+  /* Reset the signal handlers in the child, but don't free the
+     trap strings.  Set a flag noting that we have to free the
+     trap strings if we run trap to change a signal disposition. */
+  clear_pending_traps ();
+  reset_signal_handlers ();
+  subshell_environment |= SUBSHELL_RESETTRAP;
+  /* Note that signal handlers have been reset, so we should no longer
+    reset the handler and resend trapped signals to ourselves. */
+  subshell_environment &= ~SUBSHELL_IGNTRAP;
+
+  /* We are in a subshell, so forget that we are running a trap handler or
+     that the signal handler has changed (we haven't changed it!) */
+  /* XXX - maybe do this for `real' signals and not ERR/DEBUG/RETURN/EXIT
+     traps? */
+  if (running_trap > 0)
+    {
+      run_trap_cleanup (running_trap - 1);
+      running_trap = 0;		/* XXX - maybe leave this */
+    }
+
+  /* Make sure restore_original_signals doesn't undo the work done by
+     make_child to ensure that asynchronous children are immune to SIGINT
+     and SIGQUIT.  Turn off asynchronous to make sure more subshells are
+     not spawned. */
+  if (asynchronous)
+    {
+      setup_async_signals ();
+      asynchronous = 0;
+    }
+  else
+    set_sigint_handler ();
+
+#if defined (JOB_CONTROL)
+  set_sigchld_handler ();
+#endif /* JOB_CONTROL */
+
+  /* Delete all traces that there were any jobs running.  This is
+     only for subshells. */
+  without_job_control ();
+
+  if (fds_to_close)
+    close_fd_bitmap (fds_to_close);
+
+  do_piping (pipe_in, pipe_out);
+
+#if defined (COPROCESS_SUPPORT)
+  coproc_closeall ();
+#endif
+
+#if defined (PROCESS_SUBSTITUTION)
+  clear_fifo_list ();		/* XXX- we haven't created any FIFOs */
+#endif
+
+  /* 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.
+     Note that an input pipe to a compound command suffices to inhibit
+     the implicit /dev/null redirection for asynchronous commands
+     executed as part of that compound command. */
+  if (user_subshell)
+    {
+      stdin_redir = stdin_redirects (command->redirects) || pipe_in != NO_PIPE;
+#if 0
+      restore_default_signal (EXIT_TRAP);	/* XXX - reset_signal_handlers above */
+#endif
+    }
+  else if (shell_control_structure (command->type) && pipe_in != NO_PIPE)
+    stdin_redir = 1;
+
+  /* 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 ();
+
+#if defined (BUFFERED_INPUT)
+  /* In any case, we are not reading our command input from stdin. */
+  default_buffered_input = -1;
+#endif
+
+  /* We can't optimize away forks if one of the commands executed by the
+     subshell sets an exit trap, so we set CMD_NO_FORK for simple commands
+     and set CMD_TRY_OPTIMIZING for simple commands on the right side of an
+     and-or or `;' list to test for optimizing forks when they are executed. */
+  if (user_subshell && command->type == cm_subshell &&
+      (command->flags & (CMD_TIME_PIPELINE|CMD_INVERT_RETURN)) == 0)
+    optimize_subshell_command (command->value.Subshell->command);
+
+  /* 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;
+    }
+
+  if (command->type == cm_subshell)
+    tcom = command->value.Subshell->command;
+  else if (user_coproc)
+    tcom = command->value.Coproc->command;
+  else
+    tcom = 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 || user_coproc) && (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;
+
+  result = setjmp_nosigs (top_level);
+
+  /* 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_nosigs (return_catch);
+
+  /* If we're going to exit the shell, we don't want to invert the return
+     status. */
+  if (result == EXITPROG || result == EXITBLTIN)
+    invert = 0, return_code = last_command_exit_value;
+  else if (result)
+    return_code = (last_command_exit_value == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : last_command_exit_value;
+  else if (function_value)
+    return_code = return_catch_value;
+  else
+    return_code = execute_command_internal ((COMMAND *)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 ();
+    }
+
+#if 0
+  subshell_level--;		/* don't bother, caller will just exit */
+#endif
+  return (return_code);
+  /* NOTREACHED */
+}
+
+#if defined (COPROCESS_SUPPORT)
+#define COPROC_MAX	16
+
+typedef struct cpelement
+  {
+    struct cpelement *next;
+    struct coproc *coproc;
+  }
+cpelement_t;
+    
+typedef struct cplist
+  {
+    struct cpelement *head;
+    struct cpelement *tail;
+    int ncoproc;
+    int lock;
+  }
+cplist_t;
+
+static struct cpelement *cpe_alloc PARAMS((struct coproc *));
+static void cpe_dispose PARAMS((struct cpelement *));
+static struct cpelement *cpl_add PARAMS((struct coproc *));
+static struct cpelement *cpl_delete PARAMS((pid_t));
+static void cpl_reap PARAMS((void));
+static void cpl_flush PARAMS((void));
+static void cpl_closeall PARAMS((void));
+static struct cpelement *cpl_search PARAMS((pid_t));
+static struct cpelement *cpl_searchbyname PARAMS((const char *));
+static void cpl_prune PARAMS((void));
+
+static void coproc_free PARAMS((struct coproc *));
+
+/* Will go away when there is fully-implemented support for multiple coprocs. */
+Coproc sh_coproc = { 0, NO_PID, -1, -1, 0, 0, 0, 0, 0 };
+
+cplist_t coproc_list = {0, 0, 0};
+
+/* Functions to manage the list of coprocs */
+
+static struct cpelement *
+cpe_alloc (cp)
+     Coproc *cp;
+{
+  struct cpelement *cpe;
+
+  cpe = (struct cpelement *)xmalloc (sizeof (struct cpelement));
+  cpe->coproc = cp;
+  cpe->next = (struct cpelement *)0;
+  return cpe;
+}
+
+static void
+cpe_dispose (cpe)
+      struct cpelement *cpe;
+{
+  free (cpe);
+}
+
+static struct cpelement *
+cpl_add (cp)
+     Coproc *cp;
+{
+  struct cpelement *cpe;
+
+  cpe = cpe_alloc (cp);
+
+  if (coproc_list.head == 0)
+    {
+      coproc_list.head = coproc_list.tail = cpe;
+      coproc_list.ncoproc = 0;			/* just to make sure */
+    }
+  else
+    {
+      coproc_list.tail->next = cpe;
+      coproc_list.tail = cpe;
+    }
+  coproc_list.ncoproc++;
+
+  return cpe;
+}
+
+static struct cpelement *
+cpl_delete (pid)
+     pid_t pid;
+{
+  struct cpelement *prev, *p;
+
+  for (prev = p = coproc_list.head; p; prev = p, p = p->next)
+    if (p->coproc->c_pid == pid)
+      {
+        prev->next = p->next;	/* remove from list */
+        break;
+      }
+
+  if (p == 0)
+    return 0;		/* not found */
+
+  INTERNAL_DEBUG (("cpl_delete: deleting %d", pid));
+
+  /* Housekeeping in the border cases. */
+  if (p == coproc_list.head)
+    coproc_list.head = coproc_list.head->next;
+  else if (p == coproc_list.tail)
+    coproc_list.tail = prev;
+
+  coproc_list.ncoproc--;
+  if (coproc_list.ncoproc == 0)
+    coproc_list.head = coproc_list.tail = 0;
+  else if (coproc_list.ncoproc == 1)
+    coproc_list.tail = coproc_list.head;		/* just to make sure */
+
+  return (p);
+}
+
+static void
+cpl_reap ()
+{
+  struct cpelement *p, *next, *nh, *nt;
+
+  /* Build a new list by removing dead coprocs and fix up the coproc_list
+     pointers when done. */
+  nh = nt = next = (struct cpelement *)0;
+  for (p = coproc_list.head; p; p = next)
+    {
+      next = p->next;
+      if (p->coproc->c_flags & COPROC_DEAD)
+	{
+	  coproc_list.ncoproc--;	/* keep running count, fix up pointers later */
+	  INTERNAL_DEBUG (("cpl_reap: deleting %d", p->coproc->c_pid));
+	  coproc_dispose (p->coproc);
+	  cpe_dispose (p);
+	}
+      else if (nh == 0)
+	nh = nt = p;
+      else
+	{
+	  nt->next = p;
+	  nt = nt->next;
+	}
+    }
+
+  if (coproc_list.ncoproc == 0)
+    coproc_list.head = coproc_list.tail = 0;
+  else
+    {
+      if (nt)
+        nt->next = 0;
+      coproc_list.head = nh;
+      coproc_list.tail = nt;
+      if (coproc_list.ncoproc == 1)
+	coproc_list.tail = coproc_list.head;		/* just to make sure */  
+    }
+}
+
+/* Clear out the list of saved statuses */
+static void
+cpl_flush ()
+{
+  struct cpelement *cpe, *p;
+
+  for (cpe = coproc_list.head; cpe; )
+    {
+      p = cpe;
+      cpe = cpe->next;
+
+      coproc_dispose (p->coproc);
+      cpe_dispose (p);
+    }
+
+  coproc_list.head = coproc_list.tail = 0;
+  coproc_list.ncoproc = 0;
+}
+
+static void
+cpl_closeall ()
+{
+  struct cpelement *cpe;
+
+  for (cpe = coproc_list.head; cpe; cpe = cpe->next)
+    coproc_close (cpe->coproc);
+}
+
+static void
+cpl_fdchk (fd)
+     int fd;
+{
+  struct cpelement *cpe;
+
+  for (cpe = coproc_list.head; cpe; cpe = cpe->next)
+    coproc_checkfd (cpe->coproc, fd);
+}
+
+/* Search for PID in the list of coprocs; return the cpelement struct if
+   found.  If not found, return NULL. */
+static struct cpelement *
+cpl_search (pid)
+     pid_t pid;
+{
+  struct cpelement *cpe;
+
+  for (cpe = coproc_list.head ; cpe; cpe = cpe->next)
+    if (cpe->coproc->c_pid == pid)
+      return cpe;
+  return (struct cpelement *)NULL;
+}
+
+/* Search for the coproc named NAME in the list of coprocs; return the
+   cpelement struct if found.  If not found, return NULL. */
+static struct cpelement *
+cpl_searchbyname (name)
+     const char *name;
+{
+  struct cpelement *cp;
+
+  for (cp = coproc_list.head ; cp; cp = cp->next)
+    if (STREQ (cp->coproc->c_name, name))
+      return cp;
+  return (struct cpelement *)NULL;
+}
+
+static pid_t
+cpl_firstactive ()
+{
+  struct cpelement *cpe;
+
+  for (cpe = coproc_list.head ; cpe; cpe = cpe->next)
+    if ((cpe->coproc->c_flags & COPROC_DEAD) == 0)
+      return cpe->coproc->c_pid;
+  return (pid_t)NO_PID;
+}
+
+#if 0
+static void
+cpl_prune ()
+{
+  struct cpelement *cp;
+
+  while (coproc_list.head && coproc_list.ncoproc > COPROC_MAX)
+    {
+      cp = coproc_list.head;
+      coproc_list.head = coproc_list.head->next;
+      coproc_dispose (cp->coproc);
+      cpe_dispose (cp);
+      coproc_list.ncoproc--;
+    }
+}
+#endif
+
+/* These currently use a single global "shell coproc" but are written in a
+   way to not preclude additional coprocs later (using the list management
+   package above). */
+
+struct coproc *
+getcoprocbypid (pid)
+     pid_t pid;
+{
+#if MULTIPLE_COPROCS
+  struct cpelement *p;
+
+  p = cpl_search (pid);
+  return (p ? p->coproc : 0);
+#else
+  return (pid == sh_coproc.c_pid ? &sh_coproc : 0);
+#endif
+}
+
+struct coproc *
+getcoprocbyname (name)
+     const char *name;
+{
+#if MULTIPLE_COPROCS
+  struct cpelement *p;
+
+  p = cpl_searchbyname (name);
+  return (p ? p->coproc : 0);
+#else
+  return ((sh_coproc.c_name && STREQ (sh_coproc.c_name, name)) ? &sh_coproc : 0);
+#endif
+}
+
+void
+coproc_init (cp)
+     struct coproc *cp;
+{
+  cp->c_name = 0;
+  cp->c_pid = NO_PID;
+  cp->c_rfd = cp->c_wfd = -1;
+  cp->c_rsave = cp->c_wsave = -1;
+  cp->c_flags = cp->c_status = cp->c_lock = 0;
+}
+
+struct coproc *
+coproc_alloc (name, pid)
+     char *name;
+     pid_t pid;
+{
+  struct coproc *cp;
+
+#if MULTIPLE_COPROCS
+  cp = (struct coproc *)xmalloc (sizeof (struct coproc));
+#else
+  cp = &sh_coproc;
+#endif
+  coproc_init (cp);
+  cp->c_lock = 2;
+
+  cp->c_pid = pid;
+  cp->c_name = savestring (name);
+#if MULTIPLE_COPROCS
+  cpl_add (cp);
+#endif
+  cp->c_lock = 0;
+  return (cp);
+}
+
+static void
+coproc_free (cp)
+     struct coproc *cp;
+{
+  free (cp);
+}
+
+void
+coproc_dispose (cp)
+     struct coproc *cp;
+{
+  sigset_t set, oset;
+
+  if (cp == 0)
+    return;
+
+  BLOCK_SIGNAL (SIGCHLD, set, oset);
+  cp->c_lock = 3;
+  coproc_unsetvars (cp);
+  FREE (cp->c_name);
+  coproc_close (cp);
+#if MULTIPLE_COPROCS
+  coproc_free (cp);
+#else
+  coproc_init (cp);
+  cp->c_lock = 0;
+#endif
+  UNBLOCK_SIGNAL (oset);
+}
+
+/* Placeholder for now.  Will require changes for multiple coprocs */
+void
+coproc_flush ()
+{
+#if MULTIPLE_COPROCS
+  cpl_flush ();
+#else
+  coproc_dispose (&sh_coproc);
+#endif
+}
+
+void
+coproc_close (cp)
+     struct coproc *cp;
+{
+  if (cp->c_rfd >= 0)
+    {
+      close (cp->c_rfd);
+      cp->c_rfd = -1;
+    }
+  if (cp->c_wfd >= 0)
+    {
+      close (cp->c_wfd);
+      cp->c_wfd = -1;
+    }
+  cp->c_rsave = cp->c_wsave = -1;
+}
+
+void
+coproc_closeall ()
+{
+#if MULTIPLE_COPROCS
+  cpl_closeall ();
+#else
+  coproc_close (&sh_coproc);	/* XXX - will require changes for multiple coprocs */
+#endif
+}
+
+void
+coproc_reap ()
+{
+#if MULTIPLE_COPROCS
+  cpl_reap ();
+#else
+  struct coproc *cp;
+
+  cp = &sh_coproc;		/* XXX - will require changes for multiple coprocs */
+  if (cp && (cp->c_flags & COPROC_DEAD))
+    coproc_dispose (cp);
+#endif
+}
+
+void
+coproc_rclose (cp, fd)
+     struct coproc *cp;
+     int fd;
+{
+  if (cp->c_rfd >= 0 && cp->c_rfd == fd)
+    {
+      close (cp->c_rfd);
+      cp->c_rfd = -1;
+    }
+}
+
+void
+coproc_wclose (cp, fd)
+     struct coproc *cp;
+     int fd;
+{
+  if (cp->c_wfd >= 0 && cp->c_wfd == fd)
+    {
+      close (cp->c_wfd);
+      cp->c_wfd = -1;
+    }
+}
+
+void
+coproc_checkfd (cp, fd)
+     struct coproc *cp;
+     int fd;
+{
+  int update;
+
+  update = 0;
+  if (cp->c_rfd >= 0 && cp->c_rfd == fd)
+    update = cp->c_rfd = -1;
+  if (cp->c_wfd >= 0 && cp->c_wfd == fd)
+    update = cp->c_wfd = -1;
+  if (update)
+    coproc_setvars (cp);
+}
+
+void
+coproc_fdchk (fd)
+     int fd;
+{
+#if MULTIPLE_COPROCS
+  cpl_fdchk (fd);
+#else
+  coproc_checkfd (&sh_coproc, fd);
+#endif
+}
+
+void
+coproc_fdclose (cp, fd)
+     struct coproc *cp;
+     int fd;
+{
+  coproc_rclose (cp, fd);
+  coproc_wclose (cp, fd);
+  coproc_setvars (cp);
+}
+
+void
+coproc_fdsave (cp)
+     struct coproc *cp;
+{
+  cp->c_rsave = cp->c_rfd;
+  cp->c_wsave = cp->c_wfd;
+}
+
+void
+coproc_fdrestore (cp)
+     struct coproc *cp;
+{
+  cp->c_rfd = cp->c_rsave;
+  cp->c_wfd = cp->c_wsave;
+}
+
+static void
+coproc_setstatus (cp, status)
+     struct coproc *cp;
+     int status;
+{
+  cp->c_lock = 4;
+  cp->c_status = status;
+  cp->c_flags |= COPROC_DEAD;
+  cp->c_flags &= ~COPROC_RUNNING;
+  /* Don't dispose the coproc or unset the COPROC_XXX variables because
+     this is executed in a signal handler context.  Wait until coproc_reap
+     takes care of it. */
+  cp->c_lock = 0;
+}
+
+void
+coproc_pidchk (pid, status)
+     pid_t pid;
+     int status;
+{
+  struct coproc *cp;
+
+#if MULTIPLE_COPROCS
+  struct cpelement *cpe;
+
+  /* We're not disposing the coproc because this is executed in a signal
+     handler context */
+  cpe = cpl_search (pid);
+  cp = cpe ? cpe->coproc : 0;
+#else
+  cp = getcoprocbypid (pid);
+#endif
+  if (cp)
+    coproc_setstatus (cp, status);
+}
+
+pid_t
+coproc_active ()
+{
+#if MULTIPLE_COPROCS
+  return (cpl_firstactive ());
+#else
+  return ((sh_coproc.c_flags & COPROC_DEAD) ? NO_PID : sh_coproc.c_pid);
+#endif
+}
+void
+coproc_setvars (cp)
+     struct coproc *cp;
+{
+  SHELL_VAR *v;
+  char *namevar, *t;
+  size_t l;
+  WORD_DESC w;
+#if defined (ARRAY_VARS)
+  arrayind_t ind;
+#endif
+
+  if (cp->c_name == 0)
+    return;
+
+  /* We could do more here but right now we only check the name, warn if it's
+     not a valid identifier, and refuse to create variables with invalid names
+     if a coproc with such a name is supplied. */
+  w.word = cp->c_name;
+  w.flags = 0;
+  if (check_identifier (&w, 1) == 0)
+    return;
+
+  l = strlen (cp->c_name);
+  namevar = xmalloc (l + 16);
+
+#if defined (ARRAY_VARS)
+  v = find_variable (cp->c_name);
+
+  /* This is the same code as in find_or_make_array_variable */
+  if (v == 0)
+    {
+      v = find_variable_nameref_for_create (cp->c_name, 1);
+      if (v == INVALID_NAMEREF_VALUE)
+	{
+	  free (namevar);
+	  return;
+	}
+      if (v && nameref_p (v))
+	{
+	  free (cp->c_name);
+	  cp->c_name = savestring (nameref_cell (v));
+	  v = make_new_array_variable (cp->c_name);	  
+	}
+    }
+
+  if (v && (readonly_p (v) || noassign_p (v)))
+    {
+      if (readonly_p (v))
+	err_readonly (cp->c_name);
+      free (namevar);
+      return;
+    }
+  if (v == 0)
+    v = make_new_array_variable (cp->c_name);
+  if (array_p (v) == 0)
+    v = convert_var_to_array (v);
+
+  t = itos (cp->c_rfd);
+  ind = 0;
+  v = bind_array_variable (cp->c_name, ind, t, 0);
+  free (t);
+
+  t = itos (cp->c_wfd);
+  ind = 1;
+  v = bind_array_variable (cp->c_name, ind, t, 0);
+  free (t);
+#else
+  sprintf (namevar, "%s_READ", cp->c_name);
+  t = itos (cp->c_rfd);
+  bind_variable (namevar, t, 0);
+  free (t);
+  sprintf (namevar, "%s_WRITE", cp->c_name);
+  t = itos (cp->c_wfd);
+  bind_variable (namevar, t, 0);
+  free (t);
+#endif
+
+  sprintf (namevar, "%s_PID", cp->c_name);
+  t = itos (cp->c_pid);
+  v = bind_variable (namevar, t, 0);
+  free (t);
+
+  free (namevar);
+}
+
+void
+coproc_unsetvars (cp)
+     struct coproc *cp;
+{
+  int l;
+  char *namevar;
+
+  if (cp->c_name == 0)
+    return;
+
+  l = strlen (cp->c_name);
+  namevar = xmalloc (l + 16);
+
+  sprintf (namevar, "%s_PID", cp->c_name);
+  unbind_variable_noref (namevar);  
+
+#if defined (ARRAY_VARS)
+  check_unbind_variable (cp->c_name);
+#else
+  sprintf (namevar, "%s_READ", cp->c_name);
+  unbind_variable (namevar);
+  sprintf (namevar, "%s_WRITE", cp->c_name);
+  unbind_variable (namevar);
+#endif  
+
+  free (namevar);
+}
+
+static int
+execute_coproc (command, pipe_in, pipe_out, fds_to_close)
+     COMMAND *command;
+     int pipe_in, pipe_out;
+     struct fd_bitmap *fds_to_close;
+{
+  int rpipe[2], wpipe[2], estat, invert;
+  pid_t coproc_pid;
+  Coproc *cp;
+  char *tcmd, *p, *name;
+  sigset_t set, oset;
+
+  /* XXX -- can be removed after changes to handle multiple coprocs */
+#if !MULTIPLE_COPROCS
+  if (sh_coproc.c_pid != NO_PID && (sh_coproc.c_rfd >= 0 || sh_coproc.c_wfd >= 0))
+    internal_warning (_("execute_coproc: coproc [%d:%s] still exists"), sh_coproc.c_pid, sh_coproc.c_name);
+  coproc_init (&sh_coproc);
+#endif
+
+  invert = (command->flags & CMD_INVERT_RETURN) != 0;
+
+  /* expand name without splitting - could make this dependent on a shopt option */
+  name = expand_string_unsplit_to_string (command->value.Coproc->name, 0);
+  /* Optional check -- could be relaxed */
+  if (legal_identifier (name) == 0)
+    {
+      internal_error (_("`%s': not a valid identifier"), name);
+      free (name);
+      return (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
+    }
+  else
+    {
+      free (command->value.Coproc->name);
+      command->value.Coproc->name = name;
+    }
+
+  command_string_index = 0;
+  tcmd = make_command_string (command);
+
+  sh_openpipe ((int *)&rpipe);	/* 0 = parent read, 1 = child write */
+  sh_openpipe ((int *)&wpipe); /* 0 = child read, 1 = parent write */
+
+  BLOCK_SIGNAL (SIGCHLD, set, oset);
+
+  coproc_pid = make_child (p = savestring (tcmd), FORK_ASYNC);
+
+  if (coproc_pid == 0)
+    {
+      close (rpipe[0]);
+      close (wpipe[1]);
+
+#if defined (JOB_CONTROL)
+      FREE (p);
+#endif
+
+      UNBLOCK_SIGNAL (oset);
+      estat = execute_in_subshell (command, 1, wpipe[0], rpipe[1], fds_to_close);
+
+      fflush (stdout);
+      fflush (stderr);
+
+      exit (estat);
+    }
+
+  close (rpipe[1]);
+  close (wpipe[0]);
+
+  cp = coproc_alloc (command->value.Coproc->name, coproc_pid);
+  cp->c_rfd = rpipe[0];
+  cp->c_wfd = wpipe[1];
+
+  cp->c_flags |= COPROC_RUNNING;
+
+  SET_CLOSE_ON_EXEC (cp->c_rfd);
+  SET_CLOSE_ON_EXEC (cp->c_wfd);
+
+  coproc_setvars (cp);
+
+  UNBLOCK_SIGNAL (oset);
+
+#if 0
+  itrace ("execute_coproc (%s): [%d] %s", command->value.Coproc->name, coproc_pid, the_printed_command);
+#endif
+
+  close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+  unlink_fifo_list ();
+#endif
+  stop_pipeline (1, (COMMAND *)NULL);
+  DESCRIBE_PID (coproc_pid);
+  run_pending_traps ();
+
+  return (invert ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+}
+#endif
+
+/* If S == -1, it's a special value saying to close stdin */
+static void
+restore_stdin (s)
+     int s;
+{
+  if (s == -1)
+    close (0);
+  else
+    {
+      dup2 (s, 0);
+      close (s);
+    }
+}
+
+/* Catch-all cleanup function for lastpipe code for unwind-protects */
+static void
+lastpipe_cleanup (s)
+     int s;
+{
+  set_jobs_list_frozen (s);
+}
+
+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;
+  int lstdin, lastpipe_flag, lastpipe_jid, old_frozen, stdin_valid;
+  COMMAND *cmd;
+  struct fd_bitmap *fd_bitmap;
+  pid_t lastpid;
+
+#if defined (JOB_CONTROL)
+  sigset_t set, oset;
+  BLOCK_CHILD (set, oset);
+#endif /* JOB_CONTROL */
+
+  ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+  stdin_valid = sh_validfd (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;
+    }
+
+  lastpid = last_made_pid;
+
+  /* Now execute the rightmost command in the pipeline.  */
+  if (ignore_return && cmd)
+    cmd->flags |= CMD_IGNORE_RETURN;
+
+  lastpipe_flag = 0;
+
+  begin_unwind_frame ("lastpipe-exec");
+  lstdin = -2;		/* -1 is special, meaning fd 0 is closed */
+  /* If the `lastpipe' option is set with shopt, and job control is not
+     enabled, execute the last element of non-async pipelines in the
+     current shell environment. */
+  /* prev can be 0 if fd 0 was closed when this function was executed. prev
+     will never be 0 at this point if fd 0 was valid when this function was
+     executed (though we check above). */
+  if (lastpipe_opt && job_control == 0 && asynchronous == 0 && pipe_out == NO_PIPE && prev >= 0)
+    {
+      /* -1 is a special value meaning to close stdin */
+      lstdin = (prev > 0 && stdin_valid) ? move_to_high_fd (0, 1, -1) : -1;
+      if (lstdin > 0 || lstdin == -1)
+	{
+	  do_piping (prev, pipe_out);
+	  prev = NO_PIPE;
+	  add_unwind_protect (restore_stdin, lstdin);
+	  lastpipe_flag = 1;
+	  old_frozen = freeze_jobs_list ();
+	  lastpipe_jid = stop_pipeline (0, (COMMAND *)NULL);	/* XXX */
+	  add_unwind_protect (lastpipe_cleanup, old_frozen);
+#if defined (JOB_CONTROL)
+	  UNBLOCK_CHILD (oset);		/* XXX */
+#endif
+	}
+      if (cmd)
+	cmd->flags |= CMD_LASTPIPE;
+    }	  
+  if (prev >= 0)
+    add_unwind_protect (close, prev);
+
+  exec_result = execute_command_internal (cmd, asynchronous, prev, pipe_out, fds_to_close);
+
+  if (prev >= 0)
+    close (prev);
+
+  if (lstdin > 0 || lstdin == -1)
+    restore_stdin (lstdin);
+
+#if defined (JOB_CONTROL)
+  UNBLOCK_CHILD (oset);
+#endif
+
+  QUIT;
+
+  if (lastpipe_flag)
+    {
+#if defined (JOB_CONTROL)
+      if (INVALID_JOB (lastpipe_jid) == 0)
+        {
+          append_process (savestring (the_printed_command_except_trap), dollar_dollar_pid, exec_result, lastpipe_jid);
+          lstdin = wait_for (lastpid, 0);
+        }
+      else
+	{
+	  lstdin = wait_for_single_pid (lastpid, 0);		/* checks bgpids list */
+	  if (lstdin > 256)		/* error sentinel */
+	    lstdin = 127;
+	}
+#else
+      lstdin = wait_for (lastpid, 0);
+#endif
+
+#if defined (JOB_CONTROL)
+      /* If wait_for removes the job from the jobs table, use result of last
+	 command as pipeline's exit status as usual.  The jobs list can get
+	 frozen and unfrozen at inconvenient times if there are multiple pipelines
+	 running simultaneously. */
+      if (INVALID_JOB (lastpipe_jid) == 0)
+	exec_result = job_exit_status (lastpipe_jid);
+      else if (pipefail_opt)
+	exec_result = exec_result | lstdin;	/* XXX */
+      /* otherwise we use exec_result */
+#endif
+
+      set_jobs_list_frozen (old_frozen);
+    }
+
+  discard_unwind_frame ("lastpipe-exec");
+
+  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;
+{
+  COMMAND *tc, *second;
+  int ignore_return, exec_result, was_error_trap, invert;
+  volatile int save_line_number;
+
+  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);
+
+      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);
+      QUIT;
+
+      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 ';':
+    case '\n':		/* special case, happens in command substitutions */
+      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;
+	}
+      executing_list++;
+      QUIT;
+
+#if 1
+      execute_command (command->value.Connection->first);
+#else
+      execute_command_internal (command->value.Connection->first,
+				  asynchronous, pipe_in, pipe_out,
+				  fds_to_close);
+#endif
+
+      QUIT;
+      optimize_connection_fork (command);			/* XXX */
+      exec_result = execute_command_internal (command->value.Connection->second,
+				      asynchronous, pipe_in, pipe_out,
+				      fds_to_close);
+      executing_list--;
+      break;
+
+    case '|':
+      was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
+      invert = (command->flags & CMD_INVERT_RETURN) != 0;
+      ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
+
+      SET_LINE_NUMBER (line_number);	/* XXX - save value? */
+      exec_result = execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close);
+
+      if (asynchronous)
+	{
+	  exec_result = EXECUTION_SUCCESS;
+	  invert = 0;
+	}
+
+      if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  save_line_number = line_number;
+	  line_number = line_number_for_err_trap;
+	  run_error_trap ();
+	  line_number = save_line_number;
+	}
+
+      if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
+	{
+	  last_command_exit_value = exec_result;
+	  run_pending_traps ();
+	  jump_to_top_level (ERREXIT);
+	}
+
+      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. */
+
+      executing_list++;
+      if (command->value.Connection->first)
+	command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
+
+#if 1
+      exec_result = execute_command (command->value.Connection->first);
+#else
+      exec_result = execute_command_internal (command->value.Connection->first, 0, NO_PIPE, NO_PIPE, fds_to_close);
+#endif
+      QUIT;
+      if (((command->value.Connection->connector == AND_AND) &&
+	   (exec_result == EXECUTION_SUCCESS)) ||
+	  ((command->value.Connection->connector == OR_OR) &&
+	   (exec_result != EXECUTION_SUCCESS)))
+	{
+	  optimize_connection_fork (command);
+
+	  second = command->value.Connection->second;
+	  if (ignore_return && second)
+	    second->flags |= CMD_IGNORE_RETURN;
+
+	  exec_result = execute_command (second);
+	}
+      executing_list--;
+      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;
+}
+
+/* The test used to be only for interactive_shell, but we don't want to report
+   job status when the shell is not interactive or when job control isn't
+   enabled. */
+#define REAP() \
+  do \
+    { \
+      if (job_control == 0 || interactive_shell == 0) \
+	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_BADUSAGE;
+	  jump_to_top_level (ERREXIT);
+	}
+      return (EXECUTION_FAILURE);
+    }
+
+  loop_level++;
+  identifier = for_command->name->word;
+
+  line_number = for_command->line;	/* for expansion error messages */
+  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 && running_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;
+      /* XXX - special ksh93 for command index variable handling */
+      v = find_variable_last_nameref (identifier, 1);
+      if (v && nameref_p (v))
+	{
+	  if (valid_nameref_value (list->word->word, 1) == 0)
+	    {
+	      sh_invalidid (list->word->word);
+	      v = 0;
+	    }
+	  else if (readonly_p (v))
+	    err_readonly (name_cell (v));
+	  else
+	    v = bind_variable_value (v, list->word->word, ASS_NAMEREF);
+	}
+      else
+	v = bind_variable (identifier, list->word->word, 0);
+
+      if (v == 0 || readonly_p (v) || noassign_p (v))
+	{
+	  line_number = save_line_number;
+	  if (v && 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);
+	    }
+	}
+
+      if (ifsname (identifier))
+	setifs (v);
+      else
+	stupidly_hack_special_variables (identifier);
+
+      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, eflag;
+  char *expr, *temp;
+
+  expr = l->next ? string_list (l) : l->word->word;
+  temp = expand_arith_string (expr, Q_DOUBLE_QUOTES|Q_ARITH);
+  if (l->next)
+    free (expr);
+  new = make_word_list (make_word (temp), (WORD_LIST *)NULL);
+  free (temp);
+
+  if (new)
+    {
+      if (echo_command_at_execute)
+	xtrace_print_arith_cmd (new);
+
+      command_string_index = 0;
+      print_arith_command (new);
+      if (signal_in_progress (DEBUG_TRAP) == 0 && running_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. */
+      eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED;
+      this_command_name = "((";		/* )) for expression error messages */
+      
+#if defined (DEBUGGER)
+      if (debugging_mode == 0 || r == EXECUTION_SUCCESS)
+	expresult = evalexp (new->word->word, eflag, okp);
+      else
+	{
+	  expresult = 0;
+	  if (okp)
+	    *okp = 1;
+	}
+#else
+      expresult = evalexp (new->word->word, eflag, 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 && sourcelevel == 0)
+    {
+      /* line numbers in a function start at 1 */
+      line_number -= function_line_number - 1;
+      if (line_number <= 0)
+	line_number = 1;
+    }
+
+  /* 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
+displen (s)
+     const char *s;
+{
+#if defined (HANDLE_MULTIBYTE)
+  wchar_t *wcstr;
+  size_t slen;
+  int wclen;
+
+  wcstr = 0;
+  slen = mbstowcs (wcstr, s, 0);
+  if (slen == -1)
+    slen = 0;
+  wcstr = (wchar_t *)xmalloc (sizeof (wchar_t) * (slen + 1));
+  mbstowcs (wcstr, s, slen + 1);
+  wclen = wcswidth (wcstr, slen);
+  free (wcstr);
+  return (wclen < 0 ? STRLEN(s) : wclen);
+#else
+  return (STRLEN (s));
+#endif
+}
+
+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)
+    ;
+  if (l == 0)		/* don't think this can happen */
+    return (0);
+  fprintf (stderr, "%*d%s%s", len, ind, RP_SPACE, l->word->word);
+  return (displen (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, r, oe;
+  intmax_t reply;
+  WORD_LIST *l;
+  char *repl_string, *t;
+
+  COLS = default_columns ();
+
+#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 = displen (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;
+
+      oe = executing_builtin;
+      executing_builtin = 1;
+      r = read_builtin ((WORD_LIST *)NULL);
+      executing_builtin = oe;
+      if (r != EXECUTION_SUCCESS)
+	{
+	  putchar ('\n');
+	  return ((char *)NULL);
+	}
+      repl_string = get_string_value ("REPLY");
+      if (repl_string == 0)
+	return ((char *)NULL);
+      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);		/* XXX - can't be null? */
+    }
+}
+
+/* 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 0
+  if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+  if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+    {
+      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
+
+  this_command_name = (char *)0;
+
+  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 (v == 0 || readonly_p (v) || noassign_p (v))
+	{
+	  if (v && 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);
+	    }
+	}
+
+      stupidly_hack_special_variables (identifier);
+
+      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, qflags;
+
+  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 0
+  if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+  if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+    {
+      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
+
+  /* Use the same expansions (the ones POSIX specifies) as the patterns;
+     dequote the resulting string (as POSIX specifies) since the quotes in
+     patterns are handled specially below. We have to do it in this order
+     because we're not supposed to perform word splitting. */
+  wlist = expand_word_leave_quoted (case_command->word, 0);
+  if (wlist)
+    {
+      char *t;
+      t = string_list (wlist);
+      word = dequote_string (t);
+      free (t);
+    }
+  else
+    word = savestring ("");
+  dispose_words (wlist);
+
+  retval = EXECUTION_SUCCESS;
+  ignore_return = case_command->flags & CMD_IGNORE_RETURN;
+
+  begin_unwind_frame ("case");
+  add_unwind_protect (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))
+	    {
+	      /* Convert quoted null strings into empty strings. */
+	      qflags = QGLOB_CVTNULL;
+
+	      /* We left CTLESC in place quoting CTLESC and CTLNUL after the
+	      	 call to expand_word_leave_quoted; tell quote_string_for_globbing
+	      	 to remove those here. This works for both unquoted portions of
+		 the word (which call quote_escapes) and quoted portions
+		 (which call quote_string). */
+	      qflags |= QGLOB_CTLESC;
+	      pattern = quote_string_for_globbing (es->word->word, qflags);
+	    }
+	  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);
+	  QUIT;
+
+	  if (match)
+	    {
+	      do
+		{
+		  if (clauses->action && ignore_return)
+		    clauses->action->flags |= CMD_IGNORE_RETURN;
+		  retval = execute_command (clauses->action);
+		}
+	      while ((clauses->flags & CASEPAT_FALLTHROUGH) && (clauses = clauses->next));
+	      if (clauses == 0 || (clauses->flags & CASEPAT_TESTNEXT) == 0)
+		EXIT_CASE ();
+	      else
+		break;
+	    }
+
+	  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.  The same holds
+         true for `continue'. */
+      if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS)
+	{
+	  if (breaking)
+	    breaking--;
+	  if (continuing)
+	    continuing--;
+	  break;
+	}
+      if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS)
+	{
+	  if (breaking)
+	    breaking--;
+	  if (continuing)
+	    continuing--;
+	  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, eflag;
+  intmax_t expresult;
+  WORD_LIST *new;
+  char *exp, *t;
+
+  expresult = 0;
+
+  save_line_number = line_number;
+  this_command_name = "((";	/* )) */
+  SET_LINE_NUMBER (arith_command->line);
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell && sourcelevel == 0)
+    {
+      /* line numbers in a function start at 1 */
+      line_number -= function_line_number - 1;
+      if (line_number <= 0)
+	line_number = 1;
+    }      
+
+  command_string_index = 0;
+  print_arith_command (arith_command->exp);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0 && running_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
+
+  this_command_name = "((";	/* )) */
+  t = (char *)NULL;
+  new = arith_command->exp;
+  exp = (new->next) ? (t = string_list (new)) : new->word->word;
+
+  exp = expand_arith_string (exp, Q_DOUBLE_QUOTES|Q_ARITH);
+  FREE (t);
+
+  /* If we're tracing, make a new word list with `((' at the front and `))'
+     at the back and print it. Change xtrace_print_arith_cmd to take a string
+     when I change eval_arith_for_expr to use expand_arith_string(). */
+  if (echo_command_at_execute)
+    {
+      new = make_word_list (make_word (exp ? exp : ""), (WORD_LIST *)NULL);
+      xtrace_print_arith_cmd (new);
+      dispose_words (new);
+    }
+
+  if (exp)
+    {
+      eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED;
+      expresult = evalexp (exp, eflag, &expok);
+      line_number = save_line_number;
+      free (exp);
+    }
+  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 * const nullstr = "";
+
+/* XXX - can COND ever be NULL when this is called? */
+static int
+execute_cond_node (cond)
+     COND_COM *cond;
+{
+  int result, invert, patmatch, rmatch, arith, mode, mflags, ignore;
+  char *arg1, *arg2, *op;
+#if 0
+  char *t1, *t2;
+#endif
+
+  invert = (cond->flags & CMD_INVERT_RETURN);
+  ignore = (cond->flags & CMD_IGNORE_RETURN);
+  if (ignore)
+    {
+      if (cond->left)
+	cond->left->flags |= CMD_IGNORE_RETURN;
+      if (cond->right)
+	cond->right->flags |= CMD_IGNORE_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)
+    {
+      int oa, varop, varflag;
+
+      if (ignore)
+	comsub_ignore_return++;
+      varop = STREQ (cond->op->word, "-v");
+#if defined (ARRAY_VARS)
+      varflag = (varop && valid_array_reference (cond->left->op->word, VA_NOEXPAND)) ? TEST_ARRAYEXP : 0;
+#else
+      varflag = 0;
+#endif
+      arg1 = cond_expand_word (cond->left->op, varop ? 3 : 0);
+      if (ignore)
+	comsub_ignore_return--;
+      if (arg1 == 0)
+	arg1 = nullstr;
+      if (echo_command_at_execute)
+	xtrace_print_cond_term (cond->type, invert, cond->op, arg1, (char *)NULL);
+#if defined (ARRAY_VARS)
+      if (varop)
+	oa = set_expand_once (0, 0);	/* no-op for compatibility levels <= 51 */
+#endif
+      result = unary_test (cond->op->word, arg1, varflag) ? EXECUTION_SUCCESS : EXECUTION_FAILURE;
+#if defined (ARRAY_VARS)
+      if (varop)
+	assoc_expand_once = oa;
+#endif
+      if (arg1 != nullstr)
+	free (arg1);
+    }
+  else if (cond->type == COND_BINARY)
+    {
+      rmatch = 0;
+      op = cond->op->word;
+      mode = 0;
+      patmatch = (((op[1] == '=') && (op[2] == '\0') &&
+		   (op[0] == '!' || op[0] == '=')) ||
+		  (op[0] == '=' && op[1] == '\0'));
+#if defined (COND_REGEXP)
+      rmatch = (op[0] == '=' && op[1] == '~' && op[2] == '\0');
+#endif
+      arith = STREQ (op, "-eq") || STREQ (op, "-ne") || STREQ (op, "-lt") ||
+	      STREQ (op, "-le") || STREQ (op, "-gt") || STREQ (op, "-ge");
+
+      if (arith)
+	mode = 3;
+      else if (rmatch && shell_compatibility_level > 31)
+	mode = 2;
+      else if (patmatch)
+	mode = 1;
+
+      if (ignore)
+	comsub_ignore_return++;
+      arg1 = cond_expand_word (cond->left->op, arith ? mode : 0);
+      if (ignore)
+	comsub_ignore_return--;
+      if (arg1 == 0)
+	arg1 = nullstr;
+      if (ignore)
+	comsub_ignore_return++;
+      arg2 = cond_expand_word (cond->right->op, mode);
+      if (ignore)
+	comsub_ignore_return--;
+      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
+
+#if 0
+	  t1 = strescape(arg1);
+	  t2 = strescape(arg2);
+	  itrace("execute_cond_node: sh_regmatch on `%s' and `%s'", t1, t2);
+	  free(t1);
+	  free(t2);
+#endif
+
+	  result = sh_regmatch (arg1, arg2, mflags);
+	}
+      else
+#endif /* COND_REGEXP */
+	{
+	  extended_glob = 1;
+	  result = binary_test (cond->op->word, arg1, arg2, TEST_PATMATCH|TEST_ARITHEXP|TEST_LOCALE)
+				  ? EXECUTION_SUCCESS
+				  : EXECUTION_FAILURE;
+	  extended_glob = extglob_flag;
+	}
+      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;
+
+  save_line_number = line_number;
+
+  SET_LINE_NUMBER (cond_command->line);
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell && sourcelevel == 0)
+    {
+      /* line numbers in a function start at 1 */
+      line_number -= function_line_number - 1;
+      if (line_number <= 0)
+	line_number = 1;
+    }
+  command_string_index = 0;
+  print_cond_command (cond_command);
+
+  if (signal_in_progress (DEBUG_TRAP) == 0 && running_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
+
+  this_command_name = "[[";	/* ]] */
+
+#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);
+  if (var)
+    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;
+  int forcefork, fork_flags;
+  REDIRECT *rd;
+
+  for (forcefork = 0, rd = redirects; rd; rd = rd->next)
+    {
+      forcefork += rd->rflags & REDIR_VARASSIGN;
+      /* Safety */
+      forcefork += (rd->redirector.dest == 0 || fd_is_bash_input (rd->redirector.dest)) && (INPUT_REDIRECT (rd->instruction) || TRANSLATE_REDIRECT (rd->instruction) || rd->instruction == r_close_this);
+    }
+
+  if (forcefork || 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. */
+      fork_flags = async ? FORK_ASYNC : 0;
+      if (make_child ((char *)NULL, fork_flags) == 0)
+	{
+	  /* Cancel traps, in trap.c. */
+	  restore_original_signals ();		/* XXX */
+
+	  do_piping (pipe_in, pipe_out);
+
+#if defined (COPROCESS_SUPPORT)
+	  coproc_closeall ();
+#endif
+
+	  interactive = 0;			/* XXX */
+
+	  subshell_environment = 0;
+	  if (async)
+	    subshell_environment |= SUBSHELL_ASYNC;
+	  if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+	    subshell_environment |= SUBSHELL_PIPE;
+
+	  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)
+	  if (pipe_out == NO_PIPE)
+	    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, *wcmd;
+  struct builtin *b;
+  int assoc, global, array, integer;
+
+  if (words == 0)
+    return;
+
+  b = 0;
+  assoc = global = array = integer = 0;
+
+  /* Skip over assignment statements preceding a command name */
+  wcmd = words;
+  for (wcmd = words; wcmd; wcmd = wcmd->next)
+    if ((wcmd->word->flags & W_ASSIGNMENT) == 0)
+      break;
+  /* Posix (post-2008) says that `command' doesn't change whether
+     or not the builtin it shadows is a `declaration command', even
+     though it removes other special builtin properties.  In Posix
+     mode, we skip over one or more instances of `command' and
+     deal with the next word as the assignment builtin. */
+  while (posixly_correct && wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command"))
+    wcmd = wcmd->next;
+
+  for (w = wcmd; w; w = w->next)
+    if (w->word->flags & W_ASSIGNMENT)
+      {
+      	/* Lazy builtin lookup, only do it if we find an assignment */
+	if (b == 0)
+	  {
+	    b = builtin_address_internal (wcmd->word->word, 0);
+	    if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
+	      return;
+	    else if (b && (b->flags & ASSIGNMENT_BUILTIN))
+	      wcmd->word->flags |= W_ASSNBLTIN;
+	  }
+	w->word->flags |= (W_NOSPLIT|W_NOGLOB|W_TILDEEXP|W_ASSIGNARG);
+#if defined (ARRAY_VARS)
+	if (assoc)
+	  w->word->flags |= W_ASSIGNASSOC;
+	if (array)
+	  w->word->flags |= W_ASSIGNARRAY;
+#endif
+	if (global)
+	  w->word->flags |= W_ASSNGLOBAL;
+
+	/* If we have an assignment builtin that does not create local variables,
+	   make sure we create global variables even if we internally call
+	   `declare'.  The CHKLOCAL flag means to set attributes or values on
+	   an existing local variable, if there is one. */
+	if (b && ((b->flags & (ASSIGNMENT_BUILTIN|LOCALVAR_BUILTIN)) == ASSIGNMENT_BUILTIN))
+	  w->word->flags |= W_ASSNGLOBAL|W_CHKLOCAL;
+	else if (b && (b->flags & ASSIGNMENT_BUILTIN) && (b->flags & LOCALVAR_BUILTIN) && variable_context)
+	  w->word->flags |= W_FORCELOCAL;
+      }
+#if defined (ARRAY_VARS)
+    /* Note that we saw an associative array option to a builtin that takes
+       assignment statements.  This is a bit of a kludge. */
+    else if (w->word->word[0] == '-' && (strpbrk (w->word->word+1, "Aag") != 0))
+#else
+    else if (w->word->word[0] == '-' && strchr (w->word->word+1, 'g'))
+#endif
+      {
+	if (b == 0)
+	  {
+	    b = builtin_address_internal (wcmd->word->word, 0);
+	    if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
+	      return;
+	    else if (b && (b->flags & ASSIGNMENT_BUILTIN))
+	      wcmd->word->flags |= W_ASSNBLTIN;
+	  }
+	if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'A'))
+	  assoc = 1;
+	else if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'a'))
+	  array = 1;
+	if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'g'))
+	  global = 1;
+      }
+}
+
+#if defined (ARRAY_VARS)
+/* Set W_ARRAYREF on words that are valid array references to a builtin that
+   accepts them. This is intended to completely replace assoc_expand_once in
+   time. */
+static void
+fix_arrayref_words (words)
+     WORD_LIST *words;
+{
+  WORD_LIST *w, *wcmd;
+  struct builtin *b;
+
+  if (words == 0)
+    return;
+
+  b = 0;
+
+  /* Skip over assignment statements preceding a command name */
+  wcmd = words;
+  for (wcmd = words; wcmd; wcmd = wcmd->next)
+    if ((wcmd->word->flags & W_ASSIGNMENT) == 0)
+      break;
+
+  /* Skip over `command' */
+  while (wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command"))
+    wcmd = wcmd->next;
+
+  if (wcmd == 0)
+    return;
+
+  /* If it's not an array reference builtin, we have nothing to do. */
+  b = builtin_address_internal (wcmd->word->word, 0);
+  if (b == 0 || (b->flags & ARRAYREF_BUILTIN) == 0)
+    return;
+
+  for (w = wcmd->next; w; w = w->next)
+    {
+      if (w->word && w->word->word && valid_array_reference (w->word->word, 0))
+	w->word->flags |= W_ARRAYREF;
+    }
+}
+#endif
+
+#ifndef ISOPTION
+#  define ISOPTION(s, c)  (s[0] == '-' && s[1] == c && s[2] == 0)
+#endif
+
+#define RETURN_NOT_COMMAND() \
+  do { if (typep) *typep = 0; return words; } while (0)
+
+/* Make sure we have `command [-p] command_name [args]', and handle skipping
+   over the usual `--' that ends the options.  Returns the updated WORDS with
+   the command and options stripped and sets *TYPEP to a non-zero value. If
+   any other options are supplied, or there is not a command_name, we punt
+   and return a zero value in *TYPEP without updating WORDS. */
+static WORD_LIST *
+check_command_builtin (words, typep)
+     WORD_LIST *words;
+     int *typep;
+{
+  int type;
+  WORD_LIST *w;
+
+  w = words->next;
+  type = 1;
+
+  if (w && ISOPTION (w->word->word, 'p'))	/* command -p */
+    {
+#if defined (RESTRICTED_SHELL)
+      if (restricted)
+        RETURN_NOT_COMMAND();
+#endif
+      w = w->next;
+      type = 2;
+    }
+
+  if (w && ISOPTION (w->word->word, '-'))	/* command [-p] -- */
+    w = w->next;
+  else if (w && w->word->word[0] == '-')	/* any other option */
+    RETURN_NOT_COMMAND();
+
+  if (w == 0 || w->word->word == 0)		/* must have a command_name */
+    RETURN_NOT_COMMAND();
+
+  if (typep)
+    *typep = type;
+  return w;
+}
+
+/* Return 1 if the file found by searching $PATH for PATHNAME, defaulting
+   to PATHNAME, is a directory.  Used by the autocd code below. */
+static int
+is_dirname (pathname)
+     char *pathname;
+{
+  char *temp;
+  int ret;
+
+  temp = search_for_command (pathname, 0);
+  ret = temp ? file_isdir (temp) : file_isdir (pathname);
+  free (temp);
+  return ret;
+}
+
+/* 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;
+  int fork_flags, cmdflags;
+  pid_t old_last_async_pid;
+  sh_builtin_func_t *builtin;
+  SHELL_VAR *func;
+  volatile int old_builtin, old_command_builtin;
+
+  result = EXECUTION_SUCCESS;
+  special_builtin_failed = builtin_is_special = 0;
+  command_line = (char *)0;
+
+  QUIT;
+
+  /* If we're in a function, update the line number information. */
+  if (variable_context && interactive_shell && sourcelevel == 0)
+    {
+      /* line numbers in a function start at 1 */
+      line_number -= function_line_number - 1;
+      if (line_number <= 0)
+	line_number = 1;
+    }
+
+  /* Remember what this command line looks like at invocation. */
+  command_string_index = 0;
+  print_simple_command (simple_command);
+
+#if 0
+  if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
+#else
+  if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
+#endif
+    {
+      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
+
+  cmdflags = simple_command->flags;
+
+  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 = 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)
+    {
+      char *p;
+
+      /* 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. */
+      fork_flags = async ? FORK_ASYNC : 0;
+      if (make_child (p = savestring (the_printed_command_except_trap), fork_flags) == 0)
+	{
+	  already_forked = 1;
+	  cmdflags |= CMD_NO_FORK;
+
+	  /* We redo some of what make_child() does with SUBSHELL_IGNTRAP */
+	  subshell_environment = SUBSHELL_FORK|SUBSHELL_IGNTRAP;	/* XXX */
+	  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);
+
+	  /* If we fork because of an input pipe, note input pipe for later to
+	     inhibit async commands from redirecting stdin from /dev/null */
+	  stdin_redir |= pipe_in != NO_PIPE;
+
+	  do_piping (pipe_in, pipe_out);
+	  pipe_in = pipe_out = NO_PIPE;
+#if defined (COPROCESS_SUPPORT)
+	  coproc_closeall ();
+#endif
+
+	  last_asynchronous_pid = old_last_async_pid;
+
+	  if (async)
+	    subshell_level++;		/* not for pipes yet */
+
+#if defined (JOB_CONTROL)
+	  FREE (p);			/* child doesn't use pointer */
+#endif
+	}
+      else
+	{
+	  /* Don't let simple commands that aren't the last command in a
+	     pipeline change $? for the rest of the pipeline (or at all). */
+	  if (pipe_out != NO_PIPE)
+	    result = last_command_exit_value;
+	  close_pipes (pipe_in, pipe_out);
+	  command_line = (char *)NULL;      /* don't free this. */
+	  return (result);
+	}
+    }
+
+  QUIT;		/* XXX */
+
+  /* If we are re-running this as the result of executing the `command'
+     builtin, do not expand the command words a second time. */
+  if ((cmdflags & CMD_INHIBIT_EXPANSION) == 0)
+    {
+      current_fds_to_close = fds_to_close;
+      fix_assignment_words (simple_command->words);
+#if defined (ARRAY_VARS)
+      fix_arrayref_words (simple_command->words);
+#endif
+      /* Pass the ignore return flag down to command substitutions */
+      if (cmdflags & CMD_IGNORE_RETURN)	/* XXX */
+	comsub_ignore_return++;
+      words = expand_words (simple_command->words);
+      if (cmdflags & CMD_IGNORE_RETURN)
+	comsub_ignore_return--;
+      current_fds_to_close = (struct fd_bitmap *)NULL;
+    }
+  else
+    words = copy_word_list (simple_command->words);
+
+  /* It is possible for WORDS not to have anything left in it.
+     Perhaps all the words consisted of `$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)
+	sh_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 && (cmdflags & CMD_COMMAND_BUILTIN) == 0)
+    xtrace_print_word_list (words, 1);
+
+  builtin = (sh_builtin_func_t *)NULL;
+  func = (SHELL_VAR *)NULL;
+
+  /* This test is still here in case we want to change the command builtin
+     handler code below to recursively call execute_simple_command (after
+     modifying the simple_command struct). */
+  if ((cmdflags & 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);
+    }
+
+  /* What happens in posix mode when an assignment preceding a command name
+     fails.  This should agree with the code in execute_cmd.c:
+     do_assignment_statements(), even though I don't think it's executed any
+     more. */
+  if (posixly_correct && tempenv_assign_error)
+    {
+#if defined (DEBUG)
+      /* I don't know if this clause is ever executed, so let's check */
+itrace("execute_simple_command: posix mode tempenv assignment error");
+#endif
+      last_command_exit_value = EXECUTION_FAILURE;
+#if defined (STRICT_POSIX)
+      jump_to_top_level ((interactive_shell == 0) ? FORCE_EOF : DISCARD);
+#else
+      if (interactive_shell == 0 && builtin_is_special)
+	jump_to_top_level (FORCE_EOF);
+      else if (interactive_shell == 0)
+	jump_to_top_level (DISCARD);	/* XXX - maybe change later */
+      else
+	jump_to_top_level (DISCARD);
+#endif
+    }
+  tempenv_assign_error = 0;	/* don't care about this any more */
+
+  /* This is where we handle the command builtin as a pseudo-reserved word
+     prefix. This allows us to optimize away forks if we can. */
+  old_command_builtin = -1;
+  if (builtin == 0 && func == 0)
+    {
+      WORD_LIST *disposer, *l;
+      int cmdtype;
+
+      builtin = find_shell_builtin (words->word->word);
+      while (builtin == command_builtin)
+	{
+	  disposer = words;
+	  cmdtype = 0;
+	  words = check_command_builtin (words, &cmdtype);
+	  if (cmdtype > 0)	/* command -p [--] words */
+	    {
+	      for (l = disposer; l->next != words; l = l->next)
+		;
+	      l->next = 0;
+	      dispose_words (disposer);
+	      cmdflags |= CMD_COMMAND_BUILTIN | CMD_NO_FUNCTIONS;
+	      if (cmdtype == 2)
+		cmdflags |= CMD_STDPATH;
+	      builtin = find_shell_builtin (words->word->word);
+	    }
+	  else
+	    break;
+	}
+      if (cmdflags & CMD_COMMAND_BUILTIN)
+	{
+	  old_command_builtin = executing_command_builtin;
+	  unwind_protect_int (executing_command_builtin);
+	  executing_command_builtin |= 1;
+	}        
+      builtin = 0;
+    }
+
+  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 possibililty.  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 */
+
+run_builtin:
+  /* 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 (builtin)
+        {
+	  old_builtin = executing_builtin;
+	  unwind_protect_int (executing_builtin);	/* modified in execute_builtin */
+	  if (old_command_builtin == -1)	/* sentinel, can be set above */
+	    {
+	      old_command_builtin = executing_command_builtin;
+	      unwind_protect_int (executing_command_builtin);	/* ditto and set above */
+	    }
+        }
+      if (already_forked)
+	{
+	  /* reset_terminating_signals (); */	/* XXX */
+	  /* Reset the signal handlers in the child, but don't free the
+	     trap strings.  Set a flag noting that we have to free the
+	     trap strings if we run trap to change a signal disposition. */
+	  reset_signal_handlers ();
+	  subshell_environment |= SUBSHELL_RESETTRAP;
+	  subshell_environment &= ~SUBSHELL_IGNTRAP;
+
+	  if (async)
+	    {
+	      if ((cmdflags & CMD_STDIN_REDIR) &&
+		    pipe_in == NO_PIPE &&
+		    (stdin_redirects (simple_command->redirects) == 0))
+		async_redirect_stdin ();
+	      setup_async_signals ();
+	    }
+
+	  if (async == 0)
+	    subshell_level++;
+	  execute_subshell_builtin_or_function
+	    (words, simple_command->redirects, builtin, func,
+	     pipe_in, pipe_out, async, fds_to_close,
+	     cmdflags);
+	  subshell_level--;
+	}
+      else
+	{
+	  result = execute_builtin_or_function
+	    (words, builtin, func, simple_command->redirects, fds_to_close,
+	     cmdflags);
+	  if (builtin)
+	    {
+	      if (result > EX_SHERRBASE)
+		{
+		  switch (result)
+		    {
+		    case EX_REDIRFAIL:
+		    case EX_BADASSIGN:
+		    case EX_EXPFAIL:
+		      /* These errors cause non-interactive posix mode shells to exit */
+		      if (posixly_correct && builtin_is_special && interactive_shell == 0)
+			{
+			  last_command_exit_value = EXECUTION_FAILURE;
+			  jump_to_top_level (ERREXIT);
+			}
+		      break;
+		    case EX_DISKFALLBACK:
+		      /* XXX - experimental */
+		      executing_builtin = old_builtin;
+		      executing_command_builtin = old_command_builtin;
+		      builtin = 0;
+
+		      /* The redirections have already been `undone', so this
+			 will have to do them again. But piping is forever. */
+		      pipe_in = pipe_out = -1;
+		      goto execute_from_filesystem;
+		    }
+		  result = builtin_status (result);
+		  if (builtin_is_special)
+		    special_builtin_failed = 1;	/* XXX - take command builtin into account? */
+		}
+	      /* 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 = builtin_status (result);
+	    }
+
+	  set_pipestatus_from_exit (result);
+
+	  goto return_result;
+	}
+    }
+
+  if (autocd && interactive && words->word && is_dirname (words->word->word))
+    {
+      words = make_word_list (make_word ("--"), words);
+      words = make_word_list (make_word ("cd"), words);
+      xtrace_print_word_list (words, 0);
+      func = find_function ("cd");
+      goto run_builtin;
+    }
+
+execute_from_filesystem:
+  if (command_line == 0)
+    command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : "");
+
+#if defined (PROCESS_SUBSTITUTION)
+  /* The old code did not test already_forked and only did this if
+     subshell_environment&SUBSHELL_COMSUB != 0 (comsubs and procsubs). Other
+     uses of the no-fork optimization left FIFOs in $TMPDIR */
+  if (already_forked == 0 && (cmdflags & CMD_NO_FORK) && fifos_pending() > 0)
+    cmdflags &= ~CMD_NO_FORK;
+#endif
+  result = execute_disk_command (words, simple_command->redirects, command_line,
+			pipe_in, pipe_out, async, fds_to_close,
+			cmdflags);
+
+ return_result:
+  bind_lastarg (lastarg);
+  FREE (command_line);
+  dispose_words (words);
+  if (builtin)
+    {
+      executing_builtin = old_builtin;
+      executing_command_builtin = old_command_builtin;
+    }
+  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:
+    case EX_BADSYNTAX:
+      r = EX_BADUSAGE;
+      break;
+    case EX_REDIRFAIL:
+    case EX_BADASSIGN:
+    case EX_EXPFAIL:
+      r = EXECUTION_FAILURE;
+      break;
+    default:
+      /* other special exit statuses not yet defined */
+      r = (result > EX_SHERRBASE) ? EXECUTION_FAILURE : 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 result, eval_unwind, ignexit_flag;
+  int isbltinenv, should_keep;
+  char *error_trap;
+
+  error_trap = 0;
+  should_keep = 0;
+
+  /* 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 and disable
+     the ERR trap, then restore them when the command completes.  This is
+     also a problem (as below) for the command and source/. builtins. */
+  if (subshell == 0 && (flags & CMD_IGNORE_RETURN) &&
+	(builtin == eval_builtin || (flags & CMD_COMMAND_BUILTIN) || builtin == source_builtin))
+    {
+      begin_unwind_frame ("eval_builtin");
+      unwind_protect_int (exit_immediately_on_error);
+      unwind_protect_int (builtin_ignoring_errexit);
+      error_trap = TRAP_STRING (ERROR_TRAP);
+      if (error_trap)
+	{
+	  error_trap = savestring (error_trap);
+	  add_unwind_protect (xfree, error_trap);
+	  add_unwind_protect (set_error_trap, error_trap);
+	  restore_default_signal (ERROR_TRAP);
+	}
+      exit_immediately_on_error = 0;
+      ignexit_flag = builtin_ignoring_errexit;
+      builtin_ignoring_errexit = 1;
+      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.
+     `mapfile' is a special case because it uses evalstring (same as
+     eval or source) to run its callbacks. */
+  /* SHOULD_KEEP is for the pop_scope call below; it only matters when
+     posixly_correct is set, but we should propagate the temporary environment
+     to the enclosing environment only for special builtins. */
+  isbltinenv = (builtin == source_builtin || builtin == eval_builtin || builtin == unset_builtin || builtin == mapfile_builtin);
+  should_keep = isbltinenv && builtin != mapfile_builtin;
+#if defined (HISTORY) && defined (READLINE)
+  if (builtin == fc_builtin || builtin == read_builtin)
+    {
+      isbltinenv = 1;
+      should_keep = 0;
+    }
+#endif
+
+  if (isbltinenv)
+    {
+      if (subshell == 0)
+	begin_unwind_frame ("builtin_env");
+
+      if (temporary_env)
+	{
+	  push_scope (VC_BLTNENV, temporary_env);
+	  if (flags & CMD_COMMAND_BUILTIN)
+	    should_keep = 0;
+	  if (subshell == 0)
+	    add_unwind_protect (pop_scope, should_keep ? "1" : 0);
+          temporary_env = (HASH_TABLE *)NULL;	  
+	}
+    }
+
+  if (subshell == 0 && builtin == eval_builtin)
+    {
+      if (evalnest_max > 0 && evalnest >= evalnest_max)
+	{
+	  internal_error (_("eval: maximum eval nesting level exceeded (%d)"), evalnest);
+	  evalnest = 0;
+	  jump_to_top_level (DISCARD);
+	}
+      unwind_protect_int (evalnest);
+      /* The test for subshell == 0 above doesn't make a difference */
+      evalnest++;	/* execute_subshell_builtin_or_function sets this to 0 */
+    }
+  else if (subshell == 0 && builtin == source_builtin)
+    {
+      if (sourcenest_max > 0 && sourcenest >= sourcenest_max)
+	{
+	  internal_error (_("%s: maximum source nesting level exceeded (%d)"), this_command_name, sourcenest);
+	  sourcenest = 0;
+	  jump_to_top_level (DISCARD);
+	}
+      unwind_protect_int (sourcenest);
+      /* The test for subshell == 0 above doesn't make a difference */
+      sourcenest++;	/* execute_subshell_builtin_or_function sets this to 0 */
+    }
+
+  /* `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. We don't do this if
+     it's being run by the `command' builtin, since that's supposed to inhibit
+     the special builtin properties. */
+  if (posixly_correct && subshell == 0 && builtin == return_builtin && (flags & CMD_COMMAND_BUILTIN) == 0 && temporary_env)
+    {
+      begin_unwind_frame ("return_temp_env");
+      add_unwind_protect (merge_temporary_env, (char *)NULL);
+    }
+
+  executing_builtin++;
+  executing_command_builtin |= builtin == command_builtin;
+  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)
+    {
+      builtin_ignoring_errexit = ignexit_flag;
+      exit_immediately_on_error = builtin_ignoring_errexit ? 0 : errexit_flag;
+      if (error_trap)
+	{
+	  set_error_trap (error_trap);
+	  free (error_trap);
+	}
+      discard_unwind_frame ("eval_builtin");
+    }
+
+  return (result);
+}
+
+static void
+maybe_restore_getopt_state (gs)
+     sh_getopt_state_t *gs;
+{
+  /* If we have a local copy of OPTIND and it's at the right (current)
+     context, then we restore getopt's internal state.  If not, we just
+     let it go.  We know there is a local OPTIND if gs->gs_flags & 1.
+     This is set below in execute_function() before the context is run. */
+  if (gs->gs_flags & 1)
+    sh_getopt_restore_istate (gs);
+  else
+    free (gs);
+}
+
+#if defined (ARRAY_VARS)
+void
+restore_funcarray_state (fa)
+     struct func_array_state *fa;
+{
+  SHELL_VAR *nfv;
+  ARRAY *funcname_a;
+
+  array_pop (fa->source_a);
+  array_pop (fa->lineno_a);
+
+  GET_ARRAY_FROM_VAR ("FUNCNAME", nfv, funcname_a);
+  if (nfv == fa->funcname_v)
+    array_pop (funcname_a);
+
+  free (fa);
+}
+#endif
+
+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, lineno;
+  COMMAND *tc, *fc, *save_current;
+  char *debug_trap, *error_trap, *return_trap;
+#if defined (ARRAY_VARS)
+  SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v;
+  ARRAY *funcname_a;
+  volatile ARRAY *bash_source_a;
+  volatile ARRAY *bash_lineno_a;
+  struct func_array_state *fa;
+#endif
+  FUNCTION_DEF *shell_fn;
+  char *sfile, *t;
+  sh_getopt_state_t *gs;
+  SHELL_VAR *gv;
+
+  USE_VAR(fc);
+
+  if (funcnest_max > 0 && funcnest >= funcnest_max)
+    {
+      internal_error (_("%s: maximum function nesting level exceeded (%d)"), var->name, funcnest);
+      funcnest = 0;	/* XXX - should we reset it somewhere else? */
+      jump_to_top_level (DISCARD);
+    }
+
+#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;
+
+  /* A limited attempt at optimization: shell functions at the end of command
+     substitutions that are already marked NO_FORK. */
+  if (tc && (flags & CMD_NO_FORK) && (subshell_environment & SUBSHELL_COMSUB))
+    optimize_shell_function (tc);
+
+  gs = sh_getopt_save_istate ();
+  if (subshell == 0)
+    {
+      begin_unwind_frame ("function_calling");
+      /* If the shell is in posix mode, this will push the variables in
+	 the temporary environment to the "current shell environment" (the
+	 global scope), and dispose the temporary env before setting it to
+	 NULL later. This behavior has disappeared from the latest edition
+	 of the standard, so I will eventually remove it from variables.c:
+	 push_var_context. */
+      push_context (var->name, subshell, temporary_env);
+      /* This has to be before the pop_context(), because the unwinding of
+	 local variables may cause the restore of a local declaration of
+	 OPTIND to force a getopts state reset. */
+      add_unwind_protect (maybe_restore_getopt_state, gs);
+      add_unwind_protect (pop_context, (char *)NULL);
+      unwind_protect_int (line_number);
+      unwind_protect_int (line_number_for_err_trap);
+      unwind_protect_int (function_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 (funcnest);
+      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 (maybe_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 (maybe_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 (return_trap && (signal_in_progress (DEBUG_TRAP) || ((trace_p (var) == 0) && function_trace_mode == 0)))
+    {
+      if (subshell == 0)
+	{
+	  return_trap = savestring (return_trap);
+	  add_unwind_protect (xfree, return_trap);
+	  add_unwind_protect (maybe_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 ((ARRAY *)funcname_a, this_shell_function->name);
+
+  array_push ((ARRAY *)bash_source_a, sfile);
+  lineno = GET_LINE_NUMBER ();
+  t = itos (lineno);
+  array_push ((ARRAY *)bash_lineno_a, t);
+  free (t);
+#endif
+
+#if defined (ARRAY_VARS)
+  fa = (struct func_array_state *)xmalloc (sizeof (struct func_array_state));
+  fa->source_a = (ARRAY *)bash_source_a;
+  fa->source_v = bash_source_v;
+  fa->lineno_a = (ARRAY *)bash_lineno_a;
+  fa->lineno_v = bash_lineno_v;
+  fa->funcname_a = (ARRAY *)funcname_a;
+  fa->funcname_v = funcname_v;
+  if (subshell == 0)
+    add_unwind_protect (restore_funcarray_state, fa);
+#endif
+
+  /* The temporary environment for a function is supposed to apply to
+     all commands executed within the function body. */
+
+  /* Initialize BASH_ARGC and BASH_ARGV before we blow away the positional
+     parameters */
+  if (debugging_mode || shell_compatibility_level <= 44)
+    init_bash_argv ();
+
+  remember_args (words->next, 1);
+
+  /* Update BASH_ARGV and BASH_ARGC */
+  if (debugging_mode)
+    {
+      push_args (words->next);
+      if (subshell == 0)
+	add_unwind_protect (pop_args, 0);
+    }
+
+  /* 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
+
+  if (shell_compatibility_level > 43)
+    loop_level = 0;
+
+  fc = tc;
+
+  from_return_trap = 0;
+
+  return_catch_flag++;
+  return_val = setjmp_nosigs (return_catch);
+
+  if (return_val)
+    {
+      result = return_catch_value;
+      /* Run the RETURN trap in the function's context. */
+      save_current = currently_executing_command;
+      if (from_return_trap == 0)
+	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;
+    }
+
+  /* If we have a local copy of OPTIND, note it in the saved getopts state. */
+  gv = find_variable ("OPTIND");
+  if (gv && gv->context == variable_context)
+    gs->gs_flags |= 1;
+
+  if (subshell == 0)
+    run_unwind_frame ("function_calling");
+#if defined (ARRAY_VARS)
+  else
+    {
+      restore_funcarray_state (fa);
+      /* Restore BASH_ARGC and BASH_ARGV */
+      if (debugging_mode)
+	pop_args ();
+    }
+#endif
+
+  if (variable_context == 0 || this_shell_function == 0)
+    {
+      make_funcname_visible (0);
+#if defined (PROCESS_SUBSTITUTION)
+      unlink_fifo_list ();
+#endif
+    }
+
+  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, funcvalue;
+#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;
+  if (builtin == eval_builtin)
+    evalnest = 0;
+  else if (builtin == source_builtin)
+    sourcenest = 0;
+
+  if (async)
+    subshell_environment |= SUBSHELL_ASYNC;
+  if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
+    subshell_environment |= SUBSHELL_PIPE;
+
+  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 ();
+#else
+  without_job_control ();
+#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_nosigs (top_level);
+
+      /* Give the return builtin a place to jump to when executed in a subshell
+         or pipeline */
+      funcvalue = 0;
+      if (return_catch_flag && builtin == return_builtin)
+        funcvalue = setjmp_nosigs (return_catch);
+
+      if (result == EXITPROG || result == EXITBLTIN)
+	subshell_exit (last_command_exit_value);
+      else if (result)
+	subshell_exit (EXECUTION_FAILURE);
+      else if (funcvalue)
+	subshell_exit (return_catch_value);
+      else
+	{
+	  r = execute_builtin (builtin, words, flags, 1);
+	  fflush (stdout);
+	  if (r == EX_USAGE)
+	    r = EX_BADUSAGE;
+	  /* XXX - experimental */
+	  else if (r == EX_DISKFALLBACK)
+	    {
+	      char *command_line;
+
+	      command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : "");
+	      r = execute_disk_command (words, (REDIRECT *)0, command_line,
+		  -1, -1, async, (struct fd_bitmap *)0, flags|CMD_NO_FORK);
+	    }
+	  subshell_exit (r);
+	}
+    }
+  else
+    {
+      r = execute_function (var, words, flags, fds_to_close, async, 1);
+      fflush (stdout);
+      subshell_exit (r);
+    }
+}
+
+/* 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;
+#if defined (PROCESS_SUBSTITUTION)
+  int ofifo, nfifo, osize;
+  void *ofifo_list;
+#endif
+
+#if defined (PROCESS_SUBSTITUTION)
+  begin_unwind_frame ("saved_fifos");
+  /* If we return, we longjmp and don't get a chance to restore the old
+     fifo list, so we add an unwind protect to free it */
+  ofifo = num_fifos ();
+  ofifo_list = copy_fifo_list (&osize);
+  if (ofifo_list)
+    add_unwind_protect (xfree, ofifo_list);
+#endif
+
+  if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
+    {
+      undo_partial_redirects ();
+      dispose_exec_redirects ();
+#if defined (PROCESS_SUBSTITUTION)
+      free (ofifo_list);
+#endif
+      return (EX_REDIRFAIL);	/* was EXECUTION_FAILURE */
+    }
+
+  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. */
+  fflush (stdout);
+  fpurge (stdout);
+  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)
+    {
+      int discard;
+
+      discard = 0;
+      if (saved_undo_list)
+	{
+	  dispose_redirects (saved_undo_list);
+	  discard = 1;
+	}
+      redirection_undo_list = exec_redirection_undo_list;
+      saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL;      
+      if (discard)
+	discard_unwind_frame ("saved-redirects");
+    }
+
+  if (saved_undo_list)
+    {
+      redirection_undo_list = saved_undo_list;
+      discard_unwind_frame ("saved-redirects");
+    }
+
+  undo_partial_redirects ();
+
+#if defined (PROCESS_SUBSTITUTION)
+  /* Close any FIFOs created by this builtin or function. */
+  nfifo = num_fifos ();
+  if (nfifo > ofifo)
+    close_new_fifos (ofifo_list, osize);
+  if (ofifo_list)
+    free (ofifo_list);
+  discard_unwind_frame ("saved_fifos");
+#endif
+
+  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
+    {
+      /* Make sure we get the original signal dispositions now so we don't
+	 confuse the trap builtin later if the subshell tries to use it to
+	 reset SIGINT/SIGQUIT.  Don't call set_signal_ignored; that sets
+	 the value of original_signals to SIG_IGN. Posix interpretation 751. */
+      get_original_signal (SIGINT);
+      set_signal_handler (SIGINT, SIG_IGN);
+
+      get_original_signal (SIGQUIT);
+      set_signal_handler (SIGQUIT, SIG_IGN);
+    }
+}
+
+/* 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(). */
+
+/* Name of a shell function to call when a command name is not found. */
+#ifndef NOTFOUND_HOOK
+#  define NOTFOUND_HOOK "command_not_found_handle"
+#endif
+
+static int
+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, *p;
+  int nofork, stdpath, result, fork_flags;
+  pid_t pid;
+  SHELL_VAR *hookf;
+  WORD_LIST *wl;
+
+  stdpath = (cmdflags & CMD_STDPATH);	/* use command -p path */
+  nofork = (cmdflags & CMD_NO_FORK);	/* Don't fork, just exec, if no pipes */
+  pathname = words->word->word;
+
+  p = 0;
+  result = EXECUTION_SUCCESS;
+#if defined (RESTRICTED_SHELL)
+  command = (char *)NULL;
+  if (restricted && mbschr (pathname, '/'))
+    {
+      internal_error (_("%s: restricted: cannot specify `/' in command names"),
+		    pathname);
+      result = 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 */
+
+  /* If we want to change this so `command -p' (CMD_STDPATH) does not insert
+     any pathname it finds into the hash table, it should read
+     command = search_for_command (pathname, stdpath ? CMDSRCH_STDPATH : CMDSRCH_HASH);
+  */
+  command = search_for_command (pathname, CMDSRCH_HASH|(stdpath ? CMDSRCH_STDPATH : 0));
+  QUIT;
+
+  if (command)
+    {
+      /* If we're optimizing out the fork (implicit `exec'), decrement the
+	 shell level like `exec' would do. Don't do this if we are already
+	 in a pipeline environment, assuming it's already been done. */
+      if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE && (subshell_environment & SUBSHELL_PIPE) == 0)
+	adjust_shell_level (-1);
+
+      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
+    {
+      fork_flags = async ? FORK_ASYNC : 0;
+      pid = make_child (p = savestring (command_line), fork_flags);
+    }
+
+  if (pid == 0)
+    {
+      int old_interactive;
+
+      reset_terminating_signals ();	/* XXX */
+      /* Cancel traps, in trap.c. */
+      restore_original_signals ();
+      subshell_environment &= ~SUBSHELL_IGNTRAP;
+
+#if defined (JOB_CONTROL)
+      FREE (p);
+#endif
+
+      /* 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;	/* XXX - was just = */
+
+#if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD)
+      clear_fifo_list ();	/* XXX - we haven't created any FIFOs */
+#endif
+
+      /* reset shell_pgrp to pipeline_pgrp here for word expansions performed
+         by the redirections here? */
+      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_all_fifos ();
+#endif /* PROCESS_SUBSTITUTION */
+	  exit (EXECUTION_FAILURE);
+	}
+
+#if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD)
+      /* This should only contain FIFOs created as part of redirection
+	 expansion. */
+      unlink_all_fifos ();
+#endif
+
+      if (async)
+	interactive = old_interactive;
+
+      if (command == 0)
+	{
+	  hookf = find_function (NOTFOUND_HOOK);
+	  if (hookf == 0)
+	    {
+	      /* Make sure filenames are displayed using printable characters */
+	      pathname = printable_filename (pathname, 0);
+	      internal_error (_("%s: command not found"), pathname);
+	      exit (EX_NOTFOUND);	/* Posix.2 says the exit status is 127 */
+	    }
+
+	  /* We don't want to manage process groups for processes we start
+	     from here, so we turn off job control and don't attempt to
+	     manipulate the terminal's process group. */
+	  without_job_control ();
+
+#if defined (JOB_CONTROL)
+	  set_sigchld_handler ();
+#endif
+
+	  wl = make_word_list (make_word (NOTFOUND_HOOK), words);
+	  exit (execute_shell_function (hookf, wl));
+	}
+
+      /* 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:
+      QUIT;
+
+      /* Make sure that the pipes are closed in the parent. */
+      close_pipes (pipe_in, pipe_out);
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+#if 0
+      if (variable_context == 0)
+        unlink_fifo_list ();
+#endif
+#endif
+      FREE (command);
+      return (result);
+    }
+}
+
+/* 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
+
+  /* Forget about the way job control was working. We are in a subshell. */
+  without_job_control ();
+
+#if defined (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);
+  /* XXX -- are there other things we should be resetting here? */
+  parse_and_execute_level = 0;		/* nothing left to restore it */
+
+  /* We're no longer inside a shell function. */
+  variable_context = return_catch_flag = funcnest = evalnest = sourcenest = 0;
+
+  executing_list = 0;		/* XXX */
+
+  /* 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 HASH_BANG_BUFSIZ	128
+
+#define READ_SAMPLE_BUF(file, buf, len) \
+  do \
+    { \
+      fd = open(file, O_RDONLY); \
+      if (fd >= 0) \
+	{ \
+	  len = read (fd, buf, HASH_BANG_BUFSIZ); \
+	  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;
+{
+  int larray, i, fd;
+  char sample[HASH_BANG_BUFSIZ];
+  int sample_len;
+
+  SETOSTYPE (0);		/* Some systems use for USG/POSIX semantics */
+  execve (command, args, env);
+  i = errno;			/* error from execve() */
+  CHECK_TERMSIG;
+  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)
+    {
+      /* make sure this is set correctly for file_error/report_error */
+      last_command_exit_value = (i == ENOENT) ?  EX_NOTFOUND : EX_NOEXEC; /* XXX Posix.2 says that exit status is 126 */
+      if (file_isdir (command))
+#if defined (EISDIR)
+	internal_error (_("%s: %s"), command, strerror (EISDIR));
+#else
+	internal_error (_("%s: is a directory"), command);
+#endif
+      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 if (i == ENOENT)
+	{
+	  errno = i;
+	  internal_error (_("%s: cannot execute: required file not found"), 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 > 0)
+	    sample[sample_len - 1] = '\0';
+	  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 (last_command_exit_value);
+    }
+
+  /* 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 up to 128
+     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: %s"), command, strerror (i));
+	  errno = i;
+	  return (EX_BINARY_FILE);
+	}
+    }
+
+  /* We have committed to attempting to execute the contents of this file
+     as shell commands. */
+
+  reset_parser ();
+  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 */
+
+#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
+  clear_fifo_list ();	/* pipe fds are what they are now */
+#endif
+
+  sh_longjmp (subshell_top_level, 1);
+  /*NOTREACHED*/
+}
+
+static int
+execute_intern_function (name, funcdef)
+     WORD_DESC *name;
+     FUNCTION_DEF *funcdef;
+{
+  SHELL_VAR *var;
+  char *t;
+
+  if (check_identifier (name, posixly_correct) == 0)
+    {
+      if (posixly_correct && interactive_shell == 0)
+	{
+	  last_command_exit_value = EX_BADUSAGE;
+	  jump_to_top_level (ERREXIT);
+	}
+      return (EXECUTION_FAILURE);
+    }
+
+  if (strchr (name->word, CTLESC))	/* WHY? */
+    {
+      t = dequote_escapes (name->word);
+      free (name->word);
+      name->word = t;
+    }
+
+  /* Posix interpretation 383 */
+  if (posixly_correct && find_special_builtin (name->word))
+    {
+      internal_error (_("`%s': is a special builtin"), name->word);
+      last_command_exit_value = EX_BADUSAGE;
+      jump_to_top_level (interactive_shell ? DISCARD : ERREXIT);
+    }
+
+  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);
+    }
+
+#if defined (DEBUGGER)
+  bind_function_def (name->word, funcdef, 1);
+#endif
+
+  bind_function (name->word, funcdef->command);
+  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);
+#ifdef __CYGWIN__
+      /* Let stdio know the fd may have changed from text to binary mode. */
+      freopen (NULL, "r", stdin);
+#endif /* __CYGWIN__ */
+    }
+  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);
+	}
+#ifdef __CYGWIN__
+      /* Let stdio know the fd may have changed from text to binary mode, and
+	 make sure to preserve stdout line buffering. */
+      freopen (NULL, "w", stdout);
+      sh_setlinebuf (stdout);
+#endif /* __CYGWIN__ */
+    }
+}