Adding upstream version 5.2.15.upstream/5.2.15upstream

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

1 files changed, 6590 insertions, 0 deletions

diff --git a/variables.c b/variables.c
new file mode 100644
index 0000000..1a0c2c4
--- /dev/null
+++ b/variables.c
@@ -0,0 +1,6590 @@
+/* variables.c -- Functions for hacking shell variables. */
+
+/* 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"
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include "posixtime.h"
+
+#if defined (__QNX__)
+#  if defined (__QNXNTO__)
+#    include <sys/netmgr.h>
+#  else
+#    include <sys/vc.h>
+#  endif /* !__QNXNTO__ */
+#endif /* __QNX__ */
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include "chartypes.h"
+#if defined (HAVE_PWD_H)
+#  include <pwd.h>
+#endif
+#include "bashansi.h"
+#include "bashintl.h"
+#include "filecntl.h"
+
+#define NEED_XTRACE_SET_DECL
+
+#include "shell.h"
+#include "parser.h"
+#include "flags.h"
+#include "execute_cmd.h"
+#include "findcmd.h"
+#include "mailcheck.h"
+#include "input.h"
+#include "hashcmd.h"
+#include "pathexp.h"
+#include "alias.h"
+#include "jobs.h"
+
+#include "version.h"
+
+#include "builtins/getopt.h"
+#include "builtins/common.h"
+#include "builtins/builtext.h"
+
+#if defined (READLINE)
+#  include "bashline.h"
+#  include <readline/readline.h>
+#else
+#  include <tilde/tilde.h>
+#endif
+
+#if defined (HISTORY)
+#  include "bashhist.h"
+#  include <readline/history.h>
+#endif /* HISTORY */
+
+#if defined (PROGRAMMABLE_COMPLETION)
+#  include "pcomplete.h"
+#endif
+
+#define VARIABLES_HASH_BUCKETS	1024	/* must be power of two */
+#define FUNCTIONS_HASH_BUCKETS	512
+#define TEMPENV_HASH_BUCKETS	4	/* must be power of two */
+
+#define BASHFUNC_PREFIX		"BASH_FUNC_"
+#define BASHFUNC_PREFLEN	10	/* == strlen(BASHFUNC_PREFIX */
+#define BASHFUNC_SUFFIX		"%%"
+#define BASHFUNC_SUFFLEN	2	/* == strlen(BASHFUNC_SUFFIX) */
+
+#if ARRAY_EXPORT
+#define BASHARRAY_PREFIX	"BASH_ARRAY_"
+#define BASHARRAY_PREFLEN	11
+#define BASHARRAY_SUFFIX	"%%"
+#define BASHARRAY_SUFFLEN	2
+
+#define BASHASSOC_PREFIX	"BASH_ASSOC_"
+#define BASHASSOC_PREFLEN	11
+#define BASHASSOC_SUFFIX	"%%"	/* needs to be the same as BASHARRAY_SUFFIX */
+#define BASHASSOC_SUFFLEN	2
+#endif
+
+/* flags for find_variable_internal */
+
+#define FV_FORCETEMPENV		0x01
+#define FV_SKIPINVISIBLE	0x02
+#define FV_NODYNAMIC		0x04
+
+extern char **environ;
+
+/* Variables used here and defined in other files. */
+extern time_t shell_start_time;
+extern struct timeval shellstart;
+
+/* The list of shell variables that the user has created at the global
+   scope, or that came from the environment. */
+VAR_CONTEXT *global_variables = (VAR_CONTEXT *)NULL;
+
+/* The current list of shell variables, including function scopes */
+VAR_CONTEXT *shell_variables = (VAR_CONTEXT *)NULL;
+
+/* The list of shell functions that the user has created, or that came from
+   the environment. */
+HASH_TABLE *shell_functions = (HASH_TABLE *)NULL;
+
+HASH_TABLE *invalid_env = (HASH_TABLE *)NULL;
+
+#if defined (DEBUGGER)
+/* The table of shell function definitions that the user defined or that
+   came from the environment. */
+HASH_TABLE *shell_function_defs = (HASH_TABLE *)NULL;
+#endif
+
+/* The current variable context.  This is really a count of how deep into
+   executing functions we are. */
+int variable_context = 0;
+
+/* If non-zero, local variables inherit values and attributes from a variable
+   with the same name at a previous scope. */
+int localvar_inherit = 0;
+
+/* If non-zero, calling `unset' on local variables in previous scopes marks
+   them as invisible so lookups find them unset. This is the same behavior
+   as local variables in the current local scope. */
+int localvar_unset = 0;
+
+/* The set of shell assignments which are made only in the environment
+   for a single command. */
+HASH_TABLE *temporary_env = (HASH_TABLE *)NULL;
+
+/* Set to non-zero if an assignment error occurs while putting variables
+   into the temporary environment. */
+int tempenv_assign_error;
+
+/* Some funky variables which are known about specially.  Here is where
+   "$*", "$1", and all the cruft is kept. */
+char *dollar_vars[10];
+WORD_LIST *rest_of_args = (WORD_LIST *)NULL;
+int posparam_count = 0;
+
+/* The value of $$. */
+pid_t dollar_dollar_pid;
+
+/* Non-zero means that we have to remake EXPORT_ENV. */
+int array_needs_making = 1;
+
+/* The number of times BASH has been executed.  This is set
+   by initialize_variables (). */
+int shell_level = 0;
+
+/* An array which is passed to commands as their environment.  It is
+   manufactured from the union of the initial environment and the
+   shell variables that are marked for export. */
+char **export_env = (char **)NULL;
+static int export_env_index;
+static int export_env_size;
+
+#if defined (READLINE)
+static int winsize_assignment;		/* currently assigning to LINES or COLUMNS */
+#endif
+
+SHELL_VAR nameref_invalid_value;
+static SHELL_VAR nameref_maxloop_value;
+
+static HASH_TABLE *last_table_searched;	/* hash_lookup sets this */
+static VAR_CONTEXT *last_context_searched;
+
+/* Some forward declarations. */
+static void create_variable_tables PARAMS((void));
+
+static void set_machine_vars PARAMS((void));
+static void set_home_var PARAMS((void));
+static void set_shell_var PARAMS((void));
+static char *get_bash_name PARAMS((void));
+static void initialize_shell_level PARAMS((void));
+static void uidset PARAMS((void));
+#if defined (ARRAY_VARS)
+static void make_vers_array PARAMS((void));
+#endif
+
+static SHELL_VAR *null_assign PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+#if defined (ARRAY_VARS)
+static SHELL_VAR *null_array_assign PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+#endif
+static SHELL_VAR *get_self PARAMS((SHELL_VAR *));
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *init_dynamic_array_var PARAMS((char *, sh_var_value_func_t *, sh_var_assign_func_t *, int));
+static SHELL_VAR *init_dynamic_assoc_var PARAMS((char *, sh_var_value_func_t *, sh_var_assign_func_t *, int));
+#endif
+
+static inline SHELL_VAR *set_int_value (SHELL_VAR *, intmax_t, int);
+static inline SHELL_VAR *set_string_value (SHELL_VAR *, const char *, int);
+
+static SHELL_VAR *assign_seconds PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_seconds PARAMS((SHELL_VAR *));
+static SHELL_VAR *init_seconds_var PARAMS((void));
+
+static SHELL_VAR *assign_random PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_random PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *get_urandom PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *assign_lineno PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_lineno PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *assign_subshell PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_subshell PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *get_epochseconds PARAMS((SHELL_VAR *));
+static SHELL_VAR *get_epochrealtime PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *get_bashpid PARAMS((SHELL_VAR *));
+
+static SHELL_VAR *get_bash_argv0 PARAMS((SHELL_VAR *));
+static SHELL_VAR *assign_bash_argv0 PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static void set_argv0 PARAMS((void));
+
+#if defined (HISTORY)
+static SHELL_VAR *get_histcmd PARAMS((SHELL_VAR *));
+#endif
+
+#if defined (READLINE)
+static SHELL_VAR *get_comp_wordbreaks PARAMS((SHELL_VAR *));
+static SHELL_VAR *assign_comp_wordbreaks PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+#endif
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+static SHELL_VAR *assign_dirstack PARAMS((SHELL_VAR *, char *, arrayind_t, char *));
+static SHELL_VAR *get_dirstack PARAMS((SHELL_VAR *));
+#endif
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *get_groupset PARAMS((SHELL_VAR *));
+#  if defined (DEBUGGER)
+static SHELL_VAR *get_bashargcv PARAMS((SHELL_VAR *));
+#  endif
+static SHELL_VAR *build_hashcmd PARAMS((SHELL_VAR *));
+static SHELL_VAR *get_hashcmd PARAMS((SHELL_VAR *));
+static SHELL_VAR *assign_hashcmd PARAMS((SHELL_VAR *,  char *, arrayind_t, char *));
+#  if defined (ALIAS)
+static SHELL_VAR *build_aliasvar PARAMS((SHELL_VAR *));
+static SHELL_VAR *get_aliasvar PARAMS((SHELL_VAR *));
+static SHELL_VAR *assign_aliasvar PARAMS((SHELL_VAR *,  char *, arrayind_t, char *));
+#  endif
+#endif
+
+static SHELL_VAR *get_funcname PARAMS((SHELL_VAR *));
+static SHELL_VAR *init_funcname_var PARAMS((void));
+
+static void initialize_dynamic_variables PARAMS((void));
+
+static SHELL_VAR *bind_invalid_envvar PARAMS((const char *, char *, int));
+
+static int var_sametype PARAMS((SHELL_VAR *, SHELL_VAR *));
+
+static SHELL_VAR *hash_lookup PARAMS((const char *, HASH_TABLE *));
+static SHELL_VAR *new_shell_variable PARAMS((const char *));
+static SHELL_VAR *make_new_variable PARAMS((const char *, HASH_TABLE *));
+static SHELL_VAR *bind_variable_internal PARAMS((const char *, char *, HASH_TABLE *, int, int));
+
+static void dispose_variable_value PARAMS((SHELL_VAR *));
+static void free_variable_hash_data PARAMS((PTR_T));
+
+static VARLIST *vlist_alloc PARAMS((int));
+static VARLIST *vlist_realloc PARAMS((VARLIST *, int));
+static void vlist_add PARAMS((VARLIST *, SHELL_VAR *, int));
+
+static void flatten PARAMS((HASH_TABLE *, sh_var_map_func_t *, VARLIST *, int));
+
+static int qsort_var_comp PARAMS((SHELL_VAR **, SHELL_VAR **));
+
+static SHELL_VAR **vapply PARAMS((sh_var_map_func_t *));
+static SHELL_VAR **fapply PARAMS((sh_var_map_func_t *));
+
+static int visible_var PARAMS((SHELL_VAR *));
+static int visible_and_exported PARAMS((SHELL_VAR *));
+static int export_environment_candidate PARAMS((SHELL_VAR *));
+static int local_and_exported PARAMS((SHELL_VAR *));
+static int visible_variable_in_context PARAMS((SHELL_VAR *));
+static int variable_in_context PARAMS((SHELL_VAR *));
+#if defined (ARRAY_VARS)
+static int visible_array_vars PARAMS((SHELL_VAR *));
+#endif
+
+static SHELL_VAR *find_variable_internal PARAMS((const char *, int));
+
+static SHELL_VAR *find_nameref_at_context PARAMS((SHELL_VAR *, VAR_CONTEXT *));
+static SHELL_VAR *find_variable_nameref_context PARAMS((SHELL_VAR *, VAR_CONTEXT *, VAR_CONTEXT **));
+static SHELL_VAR *find_variable_last_nameref_context PARAMS((SHELL_VAR *, VAR_CONTEXT *, VAR_CONTEXT **));
+
+static SHELL_VAR *bind_tempenv_variable PARAMS((const char *, char *));
+static void push_posix_temp_var PARAMS((PTR_T));
+static void push_temp_var PARAMS((PTR_T));
+static void propagate_temp_var PARAMS((PTR_T));
+static void dispose_temporary_env PARAMS((sh_free_func_t *));     
+
+static inline char *mk_env_string PARAMS((const char *, const char *, int));
+static char **make_env_array_from_var_list PARAMS((SHELL_VAR **));
+static char **make_var_export_array PARAMS((VAR_CONTEXT *));
+static char **make_func_export_array PARAMS((void));
+static void add_temp_array_to_env PARAMS((char **, int, int));
+
+static int n_shell_variables PARAMS((void));
+static int set_context PARAMS((SHELL_VAR *));
+
+static void push_func_var PARAMS((PTR_T));
+static void push_builtin_var PARAMS((PTR_T));
+static void push_exported_var PARAMS((PTR_T));
+
+static void delete_local_contexts PARAMS((VAR_CONTEXT *));
+
+/* This needs to be looked at again. */
+static inline void push_posix_tempvar_internal PARAMS((SHELL_VAR *, int));
+
+static inline int find_special_var PARAMS((const char *));
+
+static void
+create_variable_tables ()
+{
+  if (shell_variables == 0)
+    {
+      shell_variables = global_variables = new_var_context ((char *)NULL, 0);
+      shell_variables->scope = 0;
+      shell_variables->table = hash_create (VARIABLES_HASH_BUCKETS);
+    }
+
+  if (shell_functions == 0)
+    shell_functions = hash_create (FUNCTIONS_HASH_BUCKETS);
+
+#if defined (DEBUGGER)
+  if (shell_function_defs == 0)
+    shell_function_defs = hash_create (FUNCTIONS_HASH_BUCKETS);
+#endif
+}
+
+/* Initialize the shell variables from the current environment.
+   If PRIVMODE is nonzero, don't import functions from ENV or
+   parse $SHELLOPTS. */
+void
+initialize_shell_variables (env, privmode)
+     char **env;
+     int privmode;
+{
+  char *name, *string, *temp_string;
+  int c, char_index, string_index, string_length, ro;
+  SHELL_VAR *temp_var;
+
+  create_variable_tables ();
+
+  for (string_index = 0; env && (string = env[string_index++]); )
+    {
+      char_index = 0;
+      name = string;
+      while ((c = *string++) && c != '=')
+	;
+      if (string[-1] == '=')
+	char_index = string - name - 1;
+
+      /* If there are weird things in the environment, like `=xxx' or a
+	 string without an `=', just skip them. */
+      if (char_index == 0)
+	continue;
+
+      /* ASSERT(name[char_index] == '=') */
+      name[char_index] = '\0';
+      /* Now, name = env variable name, string = env variable value, and
+	 char_index == strlen (name) */
+
+      temp_var = (SHELL_VAR *)NULL;
+
+#if defined (FUNCTION_IMPORT)
+      /* If exported function, define it now.  Don't import functions from
+	 the environment in privileged mode. */
+      if (privmode == 0 && read_but_dont_execute == 0 && 
+          STREQN (BASHFUNC_PREFIX, name, BASHFUNC_PREFLEN) &&
+          STREQ (BASHFUNC_SUFFIX, name + char_index - BASHFUNC_SUFFLEN) &&
+	  STREQN ("() {", string, 4))
+	{
+	  size_t namelen;
+	  char *tname;		/* desired imported function name */
+
+	  namelen = char_index - BASHFUNC_PREFLEN - BASHFUNC_SUFFLEN;
+
+	  tname = name + BASHFUNC_PREFLEN;	/* start of func name */
+	  tname[namelen] = '\0';		/* now tname == func name */
+
+	  string_length = strlen (string);
+	  temp_string = (char *)xmalloc (namelen + string_length + 2);
+
+	  memcpy (temp_string, tname, namelen);
+	  temp_string[namelen] = ' ';
+	  memcpy (temp_string + namelen + 1, string, string_length + 1);
+
+	  /* Don't import function names that are invalid identifiers from the
+	     environment in posix mode, though we still allow them to be defined as
+	     shell variables. */
+	  if (absolute_program (tname) == 0 && (posixly_correct == 0 || legal_identifier (tname)))
+	    parse_and_execute (temp_string, tname, SEVAL_NONINT|SEVAL_NOHIST|SEVAL_FUNCDEF|SEVAL_ONECMD);
+	  else
+	    free (temp_string);		/* parse_and_execute does this */
+
+	  if (temp_var = find_function (tname))
+	    {
+	      VSETATTR (temp_var, (att_exported|att_imported));
+	      array_needs_making = 1;
+	    }
+	  else
+	    {
+	      if (temp_var = bind_invalid_envvar (name, string, 0))
+		{
+		  VSETATTR (temp_var, (att_exported | att_imported | att_invisible));
+		  array_needs_making = 1;
+		}
+	      last_command_exit_value = EXECUTION_FAILURE;
+	      report_error (_("error importing function definition for `%s'"), tname);
+	    }
+
+	  /* Restore original suffix */
+	  tname[namelen] = BASHFUNC_SUFFIX[0];
+	}
+      else
+#endif /* FUNCTION_IMPORT */
+#if defined (ARRAY_VARS)
+#  if ARRAY_EXPORT
+      /* Array variables may not yet be exported. */
+      if (STREQN (BASHARRAY_PREFIX, name, BASHARRAY_PREFLEN) &&
+	  STREQN (BASHARRAY_SUFFIX, name + char_index - BASHARRAY_SUFFLEN, BASHARRAY_SUFFLEN) &&
+	  *string == '(' && string[1] == '[' && string[strlen (string) - 1] == ')')
+	{
+	  size_t namelen;
+	  char *tname;		/* desired imported array variable name */
+
+	  namelen = char_index - BASHARRAY_PREFLEN - BASHARRAY_SUFFLEN;
+
+	  tname = name + BASHARRAY_PREFLEN;	/* start of variable name */
+	  tname[namelen] = '\0';		/* now tname == varname */
+	  
+	  string_length = 1;
+	  temp_string = extract_array_assignment_list (string, &string_length);
+	  temp_var = assign_array_from_string (tname, temp_string, 0);
+	  FREE (temp_string);
+	  if (temp_var)
+	    {
+	      VSETATTR (temp_var, (att_exported | att_imported));
+	      array_needs_making = 1;
+	    }
+	}
+      else if (STREQN (BASHASSOC_PREFIX, name, BASHASSOC_PREFLEN) &&
+	  STREQN (BASHASSOC_SUFFIX, name + char_index - BASHASSOC_SUFFLEN, BASHASSOC_SUFFLEN) &&
+	  *string == '(' && string[1] == '[' && string[strlen (string) - 1] == ')')
+	{
+	  size_t namelen;
+	  char *tname;		/* desired imported assoc variable name */
+
+	  namelen = char_index - BASHASSOC_PREFLEN - BASHASSOC_SUFFLEN;
+
+	  tname = name + BASHASSOC_PREFLEN;	/* start of variable name */
+	  tname[namelen] = '\0';		/* now tname == varname */
+
+	  /* need to make sure it exists as an associative array first */
+	  temp_var = find_or_make_array_variable (tname, 2);
+	  if (temp_var)
+	    {
+	      string_length = 1;
+	      temp_string = extract_array_assignment_list (string, &string_length);
+	      temp_var = assign_array_var_from_string (temp_var, temp_string, 0);
+	    }
+	  FREE (temp_string);
+	  if (temp_var)
+	    {
+	      VSETATTR (temp_var, (att_exported | att_imported));
+	      array_needs_making = 1;
+	    }
+	}
+      else
+#  endif /* ARRAY_EXPORT */
+#endif
+	{
+	  ro = 0;
+	  /* If we processed a command-line option that caused SHELLOPTS to be
+	     set, it may already be set (and read-only) by the time we process
+	     the shell's environment. */
+	  if (/* posixly_correct &&*/ STREQ (name, "SHELLOPTS"))
+	    {
+	      temp_var = find_variable ("SHELLOPTS");
+	      ro = temp_var && readonly_p (temp_var);
+	      if (temp_var)
+		VUNSETATTR (temp_var, att_readonly);
+	    }
+	  if (legal_identifier (name))
+	    {
+	      temp_var = bind_variable (name, string, 0);
+	      if (temp_var)
+		{
+		  VSETATTR (temp_var, (att_exported | att_imported));
+		  if (ro)
+		    VSETATTR (temp_var, att_readonly);
+		}
+	    }
+	  else
+	    {
+	      temp_var = bind_invalid_envvar (name, string, 0);
+	      if (temp_var)
+		VSETATTR (temp_var, (att_exported | att_imported | att_invisible));
+	    }
+	  if (temp_var)
+	    array_needs_making = 1;
+	}
+
+      name[char_index] = '=';
+      /* temp_var can be NULL if it was an exported function with a syntax
+	 error (a different bug, but it still shouldn't dump core). */
+      if (temp_var && function_p (temp_var) == 0)	/* XXX not yet */
+	{
+	  CACHE_IMPORTSTR (temp_var, name);
+	}
+    }
+
+  set_pwd ();
+
+  /* Set up initial value of $_ */
+  temp_var = set_if_not ("_", dollar_vars[0]);
+
+  /* Remember this pid. */
+  dollar_dollar_pid = getpid ();
+
+  /* Now make our own defaults in case the vars that we think are
+     important are missing. */
+  temp_var = set_if_not ("PATH", DEFAULT_PATH_VALUE);
+  temp_var = set_if_not ("TERM", "dumb");
+
+#if defined (__QNX__)
+  /* set node id -- don't import it from the environment */
+  {
+    char node_name[22];
+#  if defined (__QNXNTO__)
+    netmgr_ndtostr(ND2S_LOCAL_STR, ND_LOCAL_NODE, node_name, sizeof(node_name));
+#  else
+    qnx_nidtostr (getnid (), node_name, sizeof (node_name));
+#  endif
+    temp_var = bind_variable ("NODE", node_name, 0);
+    if (temp_var)
+      set_auto_export (temp_var);
+  }
+#endif
+
+  /* set up the prompts. */
+  if (interactive_shell)
+    {
+#if defined (PROMPT_STRING_DECODE)
+      set_if_not ("PS1", primary_prompt);
+#else
+      if (current_user.uid == -1)
+	get_current_user_info ();
+      set_if_not ("PS1", current_user.euid == 0 ? "# " : primary_prompt);
+#endif
+      set_if_not ("PS2", secondary_prompt);
+    }
+
+  if (current_user.euid == 0)
+    bind_variable ("PS4", "+ ", 0);
+  else
+    set_if_not ("PS4", "+ ");
+
+  /* Don't allow IFS to be imported from the environment. */
+  temp_var = bind_variable ("IFS", " \t\n", 0);
+  setifs (temp_var);
+
+  /* Magic machine types.  Pretty convenient. */
+  set_machine_vars ();
+
+  /* Default MAILCHECK for interactive shells.  Defer the creation of a
+     default MAILPATH until the startup files are read, because MAIL
+     names a mail file if MAILPATH is not set, and we should provide a
+     default only if neither is set. */
+  if (interactive_shell)
+    {
+      temp_var = set_if_not ("MAILCHECK", posixly_correct ? "600" : "60");
+      VSETATTR (temp_var, att_integer);
+    }
+
+  /* Do some things with shell level. */
+  initialize_shell_level ();
+
+  set_ppid ();
+
+  set_argv0 ();
+
+  /* Initialize the `getopts' stuff. */
+  temp_var = bind_variable ("OPTIND", "1", 0);
+  VSETATTR (temp_var, att_integer);
+  getopts_reset (0);
+  bind_variable ("OPTERR", "1", 0);
+  sh_opterr = 1;
+
+  if (login_shell == 1 && posixly_correct == 0)
+    set_home_var ();
+
+  /* Get the full pathname to THIS shell, and set the BASH variable
+     to it. */
+  name = get_bash_name ();
+  temp_var = bind_variable ("BASH", name, 0);
+  free (name);
+
+  /* Make the exported environment variable SHELL be the user's login
+     shell.  Note that the `tset' command looks at this variable
+     to determine what style of commands to output; if it ends in "csh",
+     then C-shell commands are output, else Bourne shell commands. */
+  set_shell_var ();
+
+  /* Make a variable called BASH_VERSION which contains the version info. */
+  bind_variable ("BASH_VERSION", shell_version_string (), 0);
+#if defined (ARRAY_VARS)
+  make_vers_array ();
+#endif
+
+  if (command_execution_string)
+    bind_variable ("BASH_EXECUTION_STRING", command_execution_string, 0);
+
+  /* Find out if we're supposed to be in Posix.2 mode via an
+     environment variable. */
+  temp_var = find_variable ("POSIXLY_CORRECT");
+  if (!temp_var)
+    temp_var = find_variable ("POSIX_PEDANTIC");
+  if (temp_var && imported_p (temp_var))
+    sv_strict_posix (temp_var->name);
+
+#if defined (HISTORY)
+  /* Set history variables to defaults, and then do whatever we would
+     do if the variable had just been set.  Do this only in the case
+     that we are remembering commands on the history list. */
+  if (remember_on_history)
+    {
+      name = bash_tilde_expand (posixly_correct ? "~/.sh_history" : "~/.bash_history", 0);
+
+      set_if_not ("HISTFILE", name);
+      free (name);
+    }
+#endif /* HISTORY */
+
+  /* Seed the random number generators. */
+  seedrand ();
+  seedrand32 ();
+
+  /* Handle some "special" variables that we may have inherited from a
+     parent shell. */
+  if (interactive_shell)
+    {
+      temp_var = find_variable ("IGNOREEOF");
+      if (!temp_var)
+	temp_var = find_variable ("ignoreeof");
+      if (temp_var && imported_p (temp_var))
+	sv_ignoreeof (temp_var->name);
+    }
+
+#if defined (HISTORY)
+  if (interactive_shell && remember_on_history)
+    {
+      sv_history_control ("HISTCONTROL");
+      sv_histignore ("HISTIGNORE");
+      sv_histtimefmt ("HISTTIMEFORMAT");
+    }
+#endif /* HISTORY */
+
+#if defined (READLINE) && defined (STRICT_POSIX)
+  /* POSIXLY_CORRECT will be 1 here if the shell was compiled
+     -DSTRICT_POSIX or if POSIXLY_CORRECT was supplied in the shell's
+     environment */
+  if (interactive_shell && posixly_correct && no_line_editing == 0)
+    rl_prefer_env_winsize = 1;
+#endif /* READLINE && STRICT_POSIX */
+
+  /* Get the user's real and effective user ids. */
+  uidset ();
+
+  temp_var = set_if_not ("BASH_LOADABLES_PATH", DEFAULT_LOADABLE_BUILTINS_PATH);
+
+  temp_var = find_variable ("BASH_XTRACEFD");
+  if (temp_var && imported_p (temp_var))
+    sv_xtracefd (temp_var->name);
+
+  sv_shcompat ("BASH_COMPAT");
+
+  /* Allow FUNCNEST to be inherited from the environment. */
+  sv_funcnest ("FUNCNEST");
+
+  /* Initialize the dynamic variables, and seed their values. */
+  initialize_dynamic_variables ();
+}
+
+/* **************************************************************** */
+/*								    */
+/*	     Setting values for special shell variables		    */
+/*								    */
+/* **************************************************************** */
+
+static void
+set_machine_vars ()
+{
+  SHELL_VAR *temp_var;
+
+  temp_var = set_if_not ("HOSTTYPE", HOSTTYPE);
+  temp_var = set_if_not ("OSTYPE", OSTYPE);
+  temp_var = set_if_not ("MACHTYPE", MACHTYPE);
+
+  temp_var = set_if_not ("HOSTNAME", current_host_name);
+}
+
+/* Set $HOME to the information in the password file if we didn't get
+   it from the environment. */
+
+/* This function is not static so the tilde and readline libraries can
+   use it. */
+char *
+sh_get_home_dir ()
+{
+  if (current_user.home_dir == 0)
+    get_current_user_info ();
+  return current_user.home_dir;
+}
+
+static void
+set_home_var ()
+{
+  SHELL_VAR *temp_var;
+
+  temp_var = find_variable ("HOME");
+  if (temp_var == 0)
+    temp_var = bind_variable ("HOME", sh_get_home_dir (), 0);
+#if 0
+  VSETATTR (temp_var, att_exported);
+#endif
+}
+
+/* Set $SHELL to the user's login shell if it is not already set.  Call
+   get_current_user_info if we haven't already fetched the shell. */
+static void
+set_shell_var ()
+{
+  SHELL_VAR *temp_var;
+
+  temp_var = find_variable ("SHELL");
+  if (temp_var == 0)
+    {
+      if (current_user.shell == 0)
+	get_current_user_info ();
+      temp_var = bind_variable ("SHELL", current_user.shell, 0);
+    }
+#if 0
+  VSETATTR (temp_var, att_exported);
+#endif
+}
+
+static char *
+get_bash_name ()
+{
+  char *name;
+
+  if ((login_shell == 1) && RELPATH(shell_name))
+    {
+      if (current_user.shell == 0)
+	get_current_user_info ();
+      name = savestring (current_user.shell);
+    }
+  else if (ABSPATH(shell_name))
+    name = savestring (shell_name);
+  else if (shell_name[0] == '.' && shell_name[1] == '/')
+    {
+      /* Fast path for common case. */
+      char *cdir;
+      int len;
+
+      cdir = get_string_value ("PWD");
+      if (cdir)
+	{
+	  len = strlen (cdir);
+	  name = (char *)xmalloc (len + strlen (shell_name) + 1);
+	  strcpy (name, cdir);
+	  strcpy (name + len, shell_name + 1);
+	}
+      else
+	name = savestring (shell_name);
+    }
+  else
+    {
+      char *tname;
+      int s;
+
+      tname = find_user_command (shell_name);
+
+      if (tname == 0)
+	{
+	  /* Try the current directory.  If there is not an executable
+	     there, just punt and use the login shell. */
+	  s = file_status (shell_name);
+	  if (s & FS_EXECABLE)
+	    {
+	      tname = make_absolute (shell_name, get_string_value ("PWD"));
+	      if (*shell_name == '.')
+		{
+		  name = sh_canonpath (tname, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
+		  if (name == 0)
+		    name = tname;
+		  else
+		    free (tname);
+		}
+	     else
+		name = tname;
+	    }
+	  else
+	    {
+	      if (current_user.shell == 0)
+		get_current_user_info ();
+	      name = savestring (current_user.shell);
+	    }
+	}
+      else
+	{
+	  name = full_pathname (tname);
+	  free (tname);
+	}
+    }
+
+  return (name);
+}
+
+void
+adjust_shell_level (change)
+     int change;
+{
+  char new_level[5], *old_SHLVL;
+  intmax_t old_level;
+  SHELL_VAR *temp_var;
+
+  old_SHLVL = get_string_value ("SHLVL");
+  if (old_SHLVL == 0 || *old_SHLVL == '\0' || legal_number (old_SHLVL, &old_level) == 0)
+    old_level = 0;
+
+  shell_level = old_level + change;
+  if (shell_level < 0)
+    shell_level = 0;
+  else if (shell_level >= 1000)
+    {
+      internal_warning (_("shell level (%d) too high, resetting to 1"), shell_level);
+      shell_level = 1;
+    }
+
+  /* We don't need the full generality of itos here. */
+  if (shell_level < 10)
+    {
+      new_level[0] = shell_level + '0';
+      new_level[1] = '\0';
+    }
+  else if (shell_level < 100)
+    {
+      new_level[0] = (shell_level / 10) + '0';
+      new_level[1] = (shell_level % 10) + '0';
+      new_level[2] = '\0';
+    }
+  else if (shell_level < 1000)
+    {
+      new_level[0] = (shell_level / 100) + '0';
+      old_level = shell_level % 100;
+      new_level[1] = (old_level / 10) + '0';
+      new_level[2] = (old_level % 10) + '0';
+      new_level[3] = '\0';
+    }
+
+  temp_var = bind_variable ("SHLVL", new_level, 0);
+  set_auto_export (temp_var);
+}
+
+static void
+initialize_shell_level ()
+{
+  adjust_shell_level (1);
+}
+
+/* If we got PWD from the environment, update our idea of the current
+   working directory.  In any case, make sure that PWD exists before
+   checking it.  It is possible for getcwd () to fail on shell startup,
+   and in that case, PWD would be undefined.  If this is an interactive
+   login shell, see if $HOME is the current working directory, and if
+   that's not the same string as $PWD, set PWD=$HOME. */
+
+void
+set_pwd ()
+{
+  SHELL_VAR *temp_var, *home_var;
+  char *temp_string, *home_string, *current_dir;
+
+  home_var = find_variable ("HOME");
+  home_string = home_var ? value_cell (home_var) : (char *)NULL;
+
+  temp_var = find_variable ("PWD");
+  /* Follow posix rules for importing PWD */
+  if (temp_var && imported_p (temp_var) &&
+      (temp_string = value_cell (temp_var)) &&
+      temp_string[0] == '/' &&
+      same_file (temp_string, ".", (struct stat *)NULL, (struct stat *)NULL))
+    {
+      current_dir = sh_canonpath (temp_string, PATH_CHECKDOTDOT|PATH_CHECKEXISTS);
+      if (current_dir == 0)
+	current_dir = get_working_directory ("shell_init");
+      else
+	set_working_directory (current_dir);
+      if (posixly_correct && current_dir)
+	{
+	  temp_var = bind_variable ("PWD", current_dir, 0);
+	  set_auto_export (temp_var);
+	}  
+      free (current_dir);
+    }
+  else if (home_string && interactive_shell && login_shell &&
+	   same_file (home_string, ".", (struct stat *)NULL, (struct stat *)NULL))
+    {
+      set_working_directory (home_string);
+      temp_var = bind_variable ("PWD", home_string, 0);
+      set_auto_export (temp_var);
+    }
+  else
+    {
+      temp_string = get_working_directory ("shell-init");
+      if (temp_string)
+	{
+	  temp_var = bind_variable ("PWD", temp_string, 0);
+	  set_auto_export (temp_var);
+	  free (temp_string);
+	}
+    }
+
+  /* According to the Single Unix Specification, v2, $OLDPWD is an
+     `environment variable' and therefore should be auto-exported.  If we
+     don't find OLDPWD in the environment, or it doesn't name a directory,
+     make a dummy invisible variable for OLDPWD, and mark it as exported. */
+  temp_var = find_variable ("OLDPWD");
+#if defined (OLDPWD_CHECK_DIRECTORY)
+  if (temp_var == 0 || value_cell (temp_var) == 0 || file_isdir (value_cell (temp_var)) == 0)
+#else
+  if (temp_var == 0 || value_cell (temp_var) == 0)
+#endif
+    {
+      temp_var = bind_variable ("OLDPWD", (char *)NULL, 0);
+      VSETATTR (temp_var, (att_exported | att_invisible));
+    }
+}
+
+/* Make a variable $PPID, which holds the pid of the shell's parent.  */
+void
+set_ppid ()
+{
+  char namebuf[INT_STRLEN_BOUND(pid_t) + 1], *name;
+  SHELL_VAR *temp_var;
+
+  name = inttostr (getppid (), namebuf, sizeof(namebuf));
+  temp_var = find_variable ("PPID");
+  if (temp_var)
+    VUNSETATTR (temp_var, (att_readonly | att_exported));
+  temp_var = bind_variable ("PPID", name, 0);
+  VSETATTR (temp_var, (att_readonly | att_integer));
+}
+
+static void
+uidset ()
+{
+  char buff[INT_STRLEN_BOUND(uid_t) + 1], *b;
+  register SHELL_VAR *v;
+
+  b = inttostr (current_user.uid, buff, sizeof (buff));
+  v = find_variable ("UID");
+  if (v == 0)
+    {
+      v = bind_variable ("UID", b, 0);
+      VSETATTR (v, (att_readonly | att_integer));
+    }
+
+  if (current_user.euid != current_user.uid)
+    b = inttostr (current_user.euid, buff, sizeof (buff));
+
+  v = find_variable ("EUID");
+  if (v == 0)
+    {
+      v = bind_variable ("EUID", b, 0);
+      VSETATTR (v, (att_readonly | att_integer));
+    }
+}
+
+#if defined (ARRAY_VARS)
+static void
+make_vers_array ()
+{
+  SHELL_VAR *vv;
+  ARRAY *av;
+  char *s, d[32], b[INT_STRLEN_BOUND(int) + 1];
+
+  unbind_variable_noref ("BASH_VERSINFO");
+
+  vv = make_new_array_variable ("BASH_VERSINFO");
+  av = array_cell (vv);
+  strcpy (d, dist_version);
+  s = strchr (d, '.');
+  if (s)
+    *s++ = '\0';
+  array_insert (av, 0, d);
+  array_insert (av, 1, s);
+  s = inttostr (patch_level, b, sizeof (b));
+  array_insert (av, 2, s);
+  s = inttostr (build_version, b, sizeof (b));
+  array_insert (av, 3, s);
+  array_insert (av, 4, release_status);
+  array_insert (av, 5, MACHTYPE);
+
+  VSETATTR (vv, att_readonly);
+}
+#endif /* ARRAY_VARS */
+
+/* Set the environment variables $LINES and $COLUMNS in response to
+   a window size change. */
+void
+sh_set_lines_and_columns (lines, cols)
+     int lines, cols;
+{
+  char val[INT_STRLEN_BOUND(int) + 1], *v;
+
+#if defined (READLINE)
+  /* If we are currently assigning to LINES or COLUMNS, don't do anything. */
+  if (winsize_assignment)
+    return;
+#endif
+
+  v = inttostr (lines, val, sizeof (val));
+  bind_variable ("LINES", v, 0);
+
+  v = inttostr (cols, val, sizeof (val));
+  bind_variable ("COLUMNS", v, 0);
+}
+
+/* **************************************************************** */
+/*								    */
+/*		   Printing variables and values		    */
+/*								    */
+/* **************************************************************** */
+
+/* Print LIST (a list of shell variables) to stdout in such a way that
+   they can be read back in. */
+void
+print_var_list (list)
+     register SHELL_VAR **list;
+{
+  register int i;
+  register SHELL_VAR *var;
+
+  for (i = 0; list && (var = list[i]); i++)
+    if (invisible_p (var) == 0)
+      print_assignment (var);
+}
+
+/* Print LIST (a list of shell functions) to stdout in such a way that
+   they can be read back in. */
+void
+print_func_list (list)
+     register SHELL_VAR **list;
+{
+  register int i;
+  register SHELL_VAR *var;
+
+  for (i = 0; list && (var = list[i]); i++)
+    {
+      printf ("%s ", var->name);
+      print_var_function (var);
+      printf ("\n");
+    }
+}
+      
+/* Print the value of a single SHELL_VAR.  No newline is
+   output, but the variable is printed in such a way that
+   it can be read back in. */
+void
+print_assignment (var)
+     SHELL_VAR *var;
+{
+  if (var_isset (var) == 0)
+    return;
+
+  if (function_p (var))
+    {
+      printf ("%s", var->name);
+      print_var_function (var);
+      printf ("\n");
+    }
+#if defined (ARRAY_VARS)
+  else if (array_p (var))
+    print_array_assignment (var, 0);
+  else if (assoc_p (var))
+    print_assoc_assignment (var, 0);
+#endif /* ARRAY_VARS */
+  else
+    {
+      printf ("%s=", var->name);
+      print_var_value (var, 1);
+      printf ("\n");
+    }
+}
+
+/* Print the value cell of VAR, a shell variable.  Do not print
+   the name, nor leading/trailing newline.  If QUOTE is non-zero,
+   and the value contains shell metacharacters, quote the value
+   in such a way that it can be read back in. */
+void
+print_var_value (var, quote)
+     SHELL_VAR *var;
+     int quote;
+{
+  char *t;
+
+  if (var_isset (var) == 0)
+    return;
+
+  if (quote && posixly_correct == 0 && ansic_shouldquote (value_cell (var)))
+    {
+      t = ansic_quote (value_cell (var), 0, (int *)0);
+      printf ("%s", t);
+      free (t);
+    }
+  else if (quote && sh_contains_shell_metas (value_cell (var)))
+    {
+      t = sh_single_quote (value_cell (var));
+      printf ("%s", t);
+      free (t);
+    }
+  else
+    printf ("%s", value_cell (var));
+}
+
+/* Print the function cell of VAR, a shell variable.  Do not
+   print the name, nor leading/trailing newline. */
+void
+print_var_function (var)
+     SHELL_VAR *var;
+{
+  char *x;
+
+  if (function_p (var) && var_isset (var))
+    {
+      x = named_function_string ((char *)NULL, function_cell(var), FUNC_MULTILINE|FUNC_EXTERNAL);
+      printf ("%s", x);
+    }
+}
+
+/* **************************************************************** */
+/*								    */
+/*		 	Dynamic Variables			    */
+/*								    */
+/* **************************************************************** */
+
+/* DYNAMIC VARIABLES
+
+   These are variables whose values are generated anew each time they are
+   referenced.  These are implemented using a pair of function pointers
+   in the struct variable: assign_func, which is called from bind_variable
+   and, if arrays are compiled into the shell, some of the functions in
+   arrayfunc.c, and dynamic_value, which is called from find_variable.
+
+   assign_func is called from bind_variable_internal, if
+   bind_variable_internal discovers that the variable being assigned to
+   has such a function.  The function is called as
+	SHELL_VAR *temp = (*(entry->assign_func)) (entry, value, ind)
+   and the (SHELL_VAR *)temp is returned as the value of bind_variable.  It
+   is usually ENTRY (self).  IND is an index for an array variable, and
+   unused otherwise.
+
+   dynamic_value is called from find_variable_internal to return a `new'
+   value for the specified dynamic variable.  If this function is NULL,
+   the variable is treated as a `normal' shell variable.  If it is not,
+   however, then this function is called like this:
+	tempvar = (*(var->dynamic_value)) (var);
+
+   Sometimes `tempvar' will replace the value of `var'.  Other times, the
+   shell will simply use the string value.  Pretty object-oriented, huh?
+
+   Be warned, though: if you `unset' a special variable, it loses its
+   special meaning, even if you subsequently set it.
+
+   The special assignment code would probably have been better put in
+   subst.c: do_assignment_internal, in the same style as
+   stupidly_hack_special_variables, but I wanted the changes as
+   localized as possible.  */
+
+#define INIT_DYNAMIC_VAR(var, val, gfunc, afunc) \
+  do \
+    { \
+      v = bind_variable (var, (val), 0); \
+      v->dynamic_value = gfunc; \
+      v->assign_func = afunc; \
+    } \
+  while (0)
+
+#define INIT_DYNAMIC_ARRAY_VAR(var, gfunc, afunc) \
+  do \
+    { \
+      v = make_new_array_variable (var); \
+      v->dynamic_value = gfunc; \
+      v->assign_func = afunc; \
+    } \
+  while (0)
+
+#define INIT_DYNAMIC_ASSOC_VAR(var, gfunc, afunc) \
+  do \
+    { \
+      v = make_new_assoc_variable (var); \
+      v->dynamic_value = gfunc; \
+      v->assign_func = afunc; \
+    } \
+  while (0)
+
+static SHELL_VAR *
+null_assign (self, value, unused, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  return (self);
+}
+
+#if defined (ARRAY_VARS)
+static SHELL_VAR *
+null_array_assign (self, value, ind, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t ind;
+     char *key;
+{
+  return (self);
+}
+#endif
+
+/* Degenerate `dynamic_value' function; just returns what's passed without
+   manipulation. */
+static SHELL_VAR *
+get_self (self)
+     SHELL_VAR *self;
+{
+  return (self);
+}
+
+#if defined (ARRAY_VARS)
+/* A generic dynamic array variable initializer.  Initialize array variable
+   NAME with dynamic value function GETFUNC and assignment function SETFUNC. */
+static SHELL_VAR *
+init_dynamic_array_var (name, getfunc, setfunc, attrs)
+     char *name;
+     sh_var_value_func_t *getfunc;
+     sh_var_assign_func_t *setfunc;
+     int attrs;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v)
+    return (v);
+  INIT_DYNAMIC_ARRAY_VAR (name, getfunc, setfunc);
+  if (attrs)
+    VSETATTR (v, attrs);
+  return v;
+}
+
+static SHELL_VAR *
+init_dynamic_assoc_var (name, getfunc, setfunc, attrs)
+     char *name;
+     sh_var_value_func_t *getfunc;
+     sh_var_assign_func_t *setfunc;
+     int attrs;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v)
+    return (v);
+  INIT_DYNAMIC_ASSOC_VAR (name, getfunc, setfunc);
+  if (attrs)
+    VSETATTR (v, attrs);
+  return v;
+}
+#endif
+
+/* Set the string value of VAR to the string representation of VALUE.
+   Right now this takes an INTMAX_T because that's what itos needs. If
+   FLAGS&1, we force the integer attribute on. */
+static inline SHELL_VAR *
+set_int_value (SHELL_VAR *var, intmax_t value, int flags)
+{
+  char *p;
+
+  p = itos (value);
+  FREE (value_cell (var));
+  var_setvalue (var, p);
+  if (flags & 1)
+    VSETATTR (var, att_integer);
+  return (var);
+}
+
+static inline SHELL_VAR *
+set_string_value (SHELL_VAR *var, const char *value, int flags)
+{
+  char *p;
+
+  if (value && *value)
+    p = savestring (value);
+  else
+    {
+      p = (char *)xmalloc (1);
+      p[0] = '\0';
+    }
+  FREE (value_cell (var));
+  var_setvalue (var, p);
+  return (var);
+}
+
+/* The value of $SECONDS.  This is the number of seconds since shell
+   invocation, or, the number of seconds since the last assignment + the
+   value of the last assignment. */
+static intmax_t seconds_value_assigned;
+
+static SHELL_VAR *
+assign_seconds (self, value, unused, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  intmax_t nval;
+  int expok;
+
+  if (integer_p (self))
+    nval = evalexp (value, 0, &expok);
+  else
+    expok = legal_number (value, &nval);
+  seconds_value_assigned = expok ? nval : 0;
+  gettimeofday (&shellstart, NULL);
+  shell_start_time = shellstart.tv_sec;
+  return (set_int_value (self, nval, integer_p (self) != 0));
+}
+
+static SHELL_VAR *
+get_seconds (var)
+     SHELL_VAR *var;
+{
+  time_t time_since_start;
+  struct timeval tv;
+
+  gettimeofday(&tv, NULL);
+  time_since_start = tv.tv_sec - shell_start_time;
+  return (set_int_value (var, seconds_value_assigned + time_since_start, 1));
+}
+
+static SHELL_VAR *
+init_seconds_var ()
+{
+  SHELL_VAR *v;
+
+  v = find_variable ("SECONDS");
+  if (v)
+    {
+      if (legal_number (value_cell(v), &seconds_value_assigned) == 0)
+	seconds_value_assigned = 0;
+    }
+  INIT_DYNAMIC_VAR ("SECONDS", (v ? value_cell (v) : (char *)NULL), get_seconds, assign_seconds);
+  return v;      
+}
+
+/* Functions for $RANDOM and $SRANDOM */
+
+int last_random_value;
+static int seeded_subshell = 0;
+
+static SHELL_VAR *
+assign_random (self, value, unused, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  intmax_t seedval;
+  int expok;
+
+  if (integer_p (self))
+    seedval = evalexp (value, 0, &expok);
+  else
+    expok = legal_number (value, &seedval);
+  if (expok == 0)
+    return (self);
+  sbrand (seedval);
+  if (subshell_environment)
+    seeded_subshell = getpid ();
+  return (set_int_value (self, seedval, integer_p (self) != 0));
+}
+
+int
+get_random_number ()
+{
+  int rv, pid;
+
+  /* Reset for command and process substitution. */
+  pid = getpid ();
+  if (subshell_environment && seeded_subshell != pid)
+    {
+      seedrand ();
+      seeded_subshell = pid;
+    }
+
+  do
+    rv = brand ();
+  while (rv == last_random_value);
+
+  return (last_random_value = rv);
+}
+
+static SHELL_VAR *
+get_random (var)
+     SHELL_VAR *var;
+{
+  int rv;
+
+  rv = get_random_number ();
+  return (set_int_value (var, rv, 1));
+}
+
+static SHELL_VAR *
+get_urandom (var)
+     SHELL_VAR *var;
+{
+  u_bits32_t rv;
+
+  rv = get_urandom32 ();
+  return (set_int_value (var, rv, 1));
+}
+
+static SHELL_VAR *
+assign_lineno (var, value, unused, key)
+     SHELL_VAR *var;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  intmax_t new_value;
+
+  if (value == 0 || *value == '\0' || legal_number (value, &new_value) == 0)
+    new_value = 0;
+  line_number = line_number_base = new_value;
+  return (set_int_value (var, line_number, integer_p (var) != 0));
+}
+
+/* Function which returns the current line number. */
+static SHELL_VAR *
+get_lineno (var)
+     SHELL_VAR *var;
+{
+  int ln;
+
+  ln = executing_line_number ();
+  return (set_int_value (var, ln, 0));
+}
+
+static SHELL_VAR *
+assign_subshell (var, value, unused, key)
+     SHELL_VAR *var;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  intmax_t new_value;
+
+  if (value == 0 || *value == '\0' || legal_number (value, &new_value) == 0)
+    new_value = 0;
+  subshell_level = new_value;
+  return var;
+}
+
+static SHELL_VAR *
+get_subshell (var)
+     SHELL_VAR *var;
+{
+  return (set_int_value (var, subshell_level, 0));
+}
+
+static SHELL_VAR *
+get_epochseconds (var)
+     SHELL_VAR *var;
+{
+  intmax_t now;
+
+  now = NOW;
+  return (set_int_value (var, now, 0));
+}
+
+static SHELL_VAR *
+get_epochrealtime (var)
+     SHELL_VAR *var;
+{
+  char buf[32];
+  struct timeval tv;
+
+  gettimeofday (&tv, NULL);
+  snprintf (buf, sizeof (buf), "%u%c%06u", (unsigned)tv.tv_sec,
+					   locale_decpoint (),
+					   (unsigned)tv.tv_usec);
+
+  return (set_string_value (var, buf, 0));
+}
+
+static SHELL_VAR *
+get_bashpid (var)
+     SHELL_VAR *var;
+{
+  int pid;
+
+  pid = getpid ();
+  return (set_int_value (var, pid, 1));
+}
+
+static SHELL_VAR *
+get_bash_argv0 (var)
+     SHELL_VAR *var;
+{
+  return (set_string_value (var, dollar_vars[0], 0));
+}
+
+static char *static_shell_name = 0;
+
+static SHELL_VAR *
+assign_bash_argv0 (var, value, unused, key)
+     SHELL_VAR *var;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  size_t vlen;
+
+  if (value == 0)
+    return var;
+
+  FREE (dollar_vars[0]);
+  dollar_vars[0] = savestring (value);
+
+  /* Need these gyrations because shell_name isn't dynamically allocated */
+  vlen = STRLEN (value);
+  static_shell_name = xrealloc (static_shell_name, vlen + 1);
+  strcpy (static_shell_name, value);
+  
+  shell_name = static_shell_name;
+  return var;
+}
+
+static void
+set_argv0 ()
+{
+  SHELL_VAR *v;
+
+  v = find_variable ("BASH_ARGV0");
+  if (v && imported_p (v))
+    assign_bash_argv0 (v, value_cell (v), 0, 0);
+}
+  
+static SHELL_VAR *
+get_bash_command (var)
+     SHELL_VAR *var;
+{
+  char *p;
+
+  p = the_printed_command_except_trap ? the_printed_command_except_trap : "";
+  return (set_string_value (var, p, 0));
+}
+
+#if defined (HISTORY)
+static SHELL_VAR *
+get_histcmd (var)
+     SHELL_VAR *var;
+{
+  int n;
+
+  /* Do the same adjustment here we do in parse.y:prompt_history_number,
+     assuming that we are in one of two states: decoding this as part of
+     the prompt string, in which case we do not want to assume that the
+     command has been saved to the history and the history number incremented,
+     or the expansion is part of the current command being executed and has
+     already been saved to history and the history number incremented.
+     Right now we use EXECUTING as the determinant. */
+  n = history_number () - executing;
+  return (set_int_value (var, n, 0));
+}
+#endif
+
+#if defined (READLINE)
+/* When this function returns, VAR->value points to malloced memory. */
+static SHELL_VAR *
+get_comp_wordbreaks (var)
+     SHELL_VAR *var;
+{
+  /* If we don't have anything yet, assign a default value. */
+  if (rl_completer_word_break_characters == 0 && bash_readline_initialized == 0)
+    enable_hostname_completion (perform_hostname_completion);
+
+  return (set_string_value (var, rl_completer_word_break_characters, 0));
+}
+
+/* When this function returns, rl_completer_word_break_characters points to
+   malloced memory. */
+static SHELL_VAR *
+assign_comp_wordbreaks (self, value, unused, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t unused;
+     char *key;
+{
+  if (rl_completer_word_break_characters &&
+      rl_completer_word_break_characters != rl_basic_word_break_characters)
+    free ((void *)rl_completer_word_break_characters);
+
+  rl_completer_word_break_characters = savestring (value);
+  return self;
+}
+#endif /* READLINE */
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+static SHELL_VAR *
+assign_dirstack (self, value, ind, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t ind;
+     char *key;
+{
+  set_dirstack_element (ind, 1, value);
+  return self;
+}
+
+static SHELL_VAR *
+get_dirstack (self)
+     SHELL_VAR *self;
+{
+  ARRAY *a;
+  WORD_LIST *l;
+
+  l = get_directory_stack (0);
+  a = array_from_word_list (l);
+  array_dispose (array_cell (self));
+  dispose_words (l);
+  var_setarray (self, a);
+  return self;
+}
+#endif /* PUSHD AND POPD && ARRAY_VARS */
+
+#if defined (ARRAY_VARS)
+/* We don't want to initialize the group set with a call to getgroups()
+   unless we're asked to, but we only want to do it once. */
+static SHELL_VAR *
+get_groupset (self)
+     SHELL_VAR *self;
+{
+  register int i;
+  int ng;
+  ARRAY *a;
+  static char **group_set = (char **)NULL;
+
+  if (group_set == 0)
+    {
+      group_set = get_group_list (&ng);
+      a = array_cell (self);
+      for (i = 0; i < ng; i++)
+	array_insert (a, i, group_set[i]);
+    }
+  return (self);
+}
+
+#  if defined (DEBUGGER)
+static SHELL_VAR *
+get_bashargcv (self)
+     SHELL_VAR *self;
+{
+  static int self_semaphore = 0;
+
+  /* Backwards compatibility: if we refer to BASH_ARGV or BASH_ARGC at the
+     top level without enabling debug mode, and we don't have an instance
+     of the variable set, initialize the arg arrays.
+     This will already have been done if debugging_mode != 0. */
+  if (self_semaphore == 0 && variable_context == 0 && debugging_mode == 0)	/* don't do it for shell functions */
+    {
+      self_semaphore = 1;
+      init_bash_argv ();
+      self_semaphore = 0;
+    }
+  return self;
+}
+#  endif
+
+static SHELL_VAR *
+build_hashcmd (self)
+     SHELL_VAR *self;
+{
+  HASH_TABLE *h;
+  int i;
+  char *k, *v;
+  BUCKET_CONTENTS *item;
+
+  h = assoc_cell (self);
+  if (h)
+    assoc_dispose (h);
+
+  if (hashed_filenames == 0 || HASH_ENTRIES (hashed_filenames) == 0)
+    {
+      var_setvalue (self, (char *)NULL);
+      return self;
+    }
+
+  h = assoc_create (hashed_filenames->nbuckets);
+  for (i = 0; i < hashed_filenames->nbuckets; i++)
+    {
+      for (item = hash_items (i, hashed_filenames); item; item = item->next)
+	{
+	  k = savestring (item->key);
+	  v = pathdata(item)->path;
+	  assoc_insert (h, k, v);
+	}
+    }
+
+  var_setvalue (self, (char *)h);
+  return self;
+}
+
+static SHELL_VAR *
+get_hashcmd (self)
+     SHELL_VAR *self;
+{
+  build_hashcmd (self);
+  return (self);
+}
+
+static SHELL_VAR *
+assign_hashcmd (self, value, ind, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t ind;
+     char *key;
+{
+#if defined (RESTRICTED_SHELL)
+  char *full_path;
+
+  if (restricted)
+    {
+      if (strchr (value, '/'))
+	{
+	  sh_restricted (value);
+	  return (SHELL_VAR *)NULL;
+	}
+      /* If we are changing the hash table in a restricted shell, make sure the
+	 target pathname can be found using a $PATH search. */
+      full_path = find_user_command (value);
+      if (full_path == 0 || *full_path == 0 || executable_file (full_path) == 0)
+	{
+	  sh_notfound (value);
+	  free (full_path);
+	  return ((SHELL_VAR *)NULL);
+	}
+      free (full_path);
+    }
+#endif
+  phash_insert (key, value, 0, 0);
+  return (build_hashcmd (self));
+}
+
+#if defined (ALIAS)
+static SHELL_VAR *
+build_aliasvar (self)
+     SHELL_VAR *self;
+{
+  HASH_TABLE *h;
+  int i;
+  char *k, *v;
+  BUCKET_CONTENTS *item;
+
+  h = assoc_cell (self);
+  if (h)
+    assoc_dispose (h);
+
+  if (aliases == 0 || HASH_ENTRIES (aliases) == 0)
+    {
+      var_setvalue (self, (char *)NULL);
+      return self;
+    }
+
+  h = assoc_create (aliases->nbuckets);
+  for (i = 0; i < aliases->nbuckets; i++)
+    {
+      for (item = hash_items (i, aliases); item; item = item->next)
+	{
+	  k = savestring (item->key);
+	  v = ((alias_t *)(item->data))->value;
+	  assoc_insert (h, k, v);
+	}
+    }
+
+  var_setvalue (self, (char *)h);
+  return self;
+}
+
+static SHELL_VAR *
+get_aliasvar (self)
+     SHELL_VAR *self;
+{
+  build_aliasvar (self);
+  return (self);
+}
+
+static SHELL_VAR *
+assign_aliasvar (self, value, ind, key)
+     SHELL_VAR *self;
+     char *value;
+     arrayind_t ind;
+     char *key;
+{
+  if (legal_alias_name (key, 0) == 0)
+    {
+       report_error (_("`%s': invalid alias name"), key);
+       return (self);
+    }
+  add_alias (key, value);
+  return (build_aliasvar (self));
+}
+#endif /* ALIAS */
+
+#endif /* ARRAY_VARS */
+
+/* If ARRAY_VARS is not defined, this just returns the name of any
+   currently-executing function.  If we have arrays, it's a call stack. */
+static SHELL_VAR *
+get_funcname (self)
+     SHELL_VAR *self;
+{
+#if ! defined (ARRAY_VARS)
+  if (variable_context && this_shell_function)
+    return (set_string_value (self, this_shell_function->name, 0));
+#endif
+  return (self);
+}
+
+void
+make_funcname_visible (on_or_off)
+     int on_or_off;
+{
+  SHELL_VAR *v;
+
+  v = find_variable ("FUNCNAME");
+  if (v == 0 || v->dynamic_value == 0)
+    return;
+
+  if (on_or_off)
+    VUNSETATTR (v, att_invisible);
+  else
+    VSETATTR (v, att_invisible);
+}
+
+static SHELL_VAR *
+init_funcname_var ()
+{
+  SHELL_VAR *v;
+
+  v = find_variable ("FUNCNAME");
+  if (v)
+    return v;
+#if defined (ARRAY_VARS)
+  INIT_DYNAMIC_ARRAY_VAR ("FUNCNAME", get_funcname, null_array_assign);
+#else
+  INIT_DYNAMIC_VAR ("FUNCNAME", (char *)NULL, get_funcname, null_assign);
+#endif
+  VSETATTR (v, att_invisible|att_noassign);
+  return v;
+}
+
+static void
+initialize_dynamic_variables ()
+{
+  SHELL_VAR *v;
+
+  v = init_seconds_var ();
+
+  INIT_DYNAMIC_VAR ("BASH_ARGV0", (char *)NULL, get_bash_argv0, assign_bash_argv0);
+
+  INIT_DYNAMIC_VAR ("BASH_COMMAND", (char *)NULL, get_bash_command, (sh_var_assign_func_t *)NULL);
+  INIT_DYNAMIC_VAR ("BASH_SUBSHELL", (char *)NULL, get_subshell, assign_subshell);
+
+  INIT_DYNAMIC_VAR ("RANDOM", (char *)NULL, get_random, assign_random);
+  VSETATTR (v, att_integer);
+  INIT_DYNAMIC_VAR ("SRANDOM", (char *)NULL, get_urandom, (sh_var_assign_func_t *)NULL);
+  VSETATTR (v, att_integer);  
+  INIT_DYNAMIC_VAR ("LINENO", (char *)NULL, get_lineno, assign_lineno);
+  VSETATTR (v, att_regenerate);
+
+  INIT_DYNAMIC_VAR ("BASHPID", (char *)NULL, get_bashpid, null_assign);
+  VSETATTR (v, att_integer);
+
+  INIT_DYNAMIC_VAR ("EPOCHSECONDS", (char *)NULL, get_epochseconds, null_assign);
+  VSETATTR (v, att_regenerate);
+  INIT_DYNAMIC_VAR ("EPOCHREALTIME", (char *)NULL, get_epochrealtime, null_assign);
+  VSETATTR (v, att_regenerate);
+
+#if defined (HISTORY)
+  INIT_DYNAMIC_VAR ("HISTCMD", (char *)NULL, get_histcmd, (sh_var_assign_func_t *)NULL);
+  VSETATTR (v, att_integer);
+#endif
+
+#if defined (READLINE)
+  INIT_DYNAMIC_VAR ("COMP_WORDBREAKS", (char *)NULL, get_comp_wordbreaks, assign_comp_wordbreaks);
+#endif
+
+#if defined (PUSHD_AND_POPD) && defined (ARRAY_VARS)
+  v = init_dynamic_array_var ("DIRSTACK", get_dirstack, assign_dirstack, 0);
+#endif /* PUSHD_AND_POPD && ARRAY_VARS */
+
+#if defined (ARRAY_VARS)
+  v = init_dynamic_array_var ("GROUPS", get_groupset, null_array_assign, att_noassign);
+
+#  if defined (DEBUGGER)
+  v = init_dynamic_array_var ("BASH_ARGC", get_bashargcv, null_array_assign, att_noassign|att_nounset);
+  v = init_dynamic_array_var ("BASH_ARGV", get_bashargcv, null_array_assign, att_noassign|att_nounset);
+#  endif /* DEBUGGER */
+  v = init_dynamic_array_var ("BASH_SOURCE", get_self, null_array_assign, att_noassign|att_nounset);
+  v = init_dynamic_array_var ("BASH_LINENO", get_self, null_array_assign, att_noassign|att_nounset);
+
+  v = init_dynamic_assoc_var ("BASH_CMDS", get_hashcmd, assign_hashcmd, att_nofree);
+#  if defined (ALIAS)
+  v = init_dynamic_assoc_var ("BASH_ALIASES", get_aliasvar, assign_aliasvar, att_nofree);
+#  endif
+#endif
+
+  v = init_funcname_var ();
+}
+
+/* **************************************************************** */
+/*								    */
+/*		Retrieving variables and values			    */
+/*								    */
+/* **************************************************************** */
+
+#if 0	/* not yet */
+int
+var_isset (var)
+     SHELL_VAR *var;
+{
+  return (var->value != 0);
+}
+
+int
+var_isunset (var)
+     SHELL_VAR *var;
+{
+  return (var->value == 0);
+}
+#endif
+
+/* How to get a pointer to the shell variable or function named NAME.
+   HASHED_VARS is a pointer to the hash table containing the list
+   of interest (either variables or functions). */
+
+static SHELL_VAR *
+hash_lookup (name, hashed_vars)
+     const char *name;
+     HASH_TABLE *hashed_vars;
+{
+  BUCKET_CONTENTS *bucket;
+
+  bucket = hash_search (name, hashed_vars, 0);
+  /* If we find the name in HASHED_VARS, set LAST_TABLE_SEARCHED to that
+     table. */
+  if (bucket)
+    last_table_searched = hashed_vars;
+  return (bucket ? (SHELL_VAR *)bucket->data : (SHELL_VAR *)NULL);
+}
+
+SHELL_VAR *
+var_lookup (name, vcontext)
+     const char *name;
+     VAR_CONTEXT *vcontext;
+{
+  VAR_CONTEXT *vc;
+  SHELL_VAR *v;
+
+  v = (SHELL_VAR *)NULL;
+  for (vc = vcontext; vc; vc = vc->down)
+    if (v = hash_lookup (name, vc->table))
+      break;
+
+  return v;
+}
+
+/* Look up the variable entry named NAME.  If SEARCH_TEMPENV is non-zero,
+   then also search the temporarily built list of exported variables.
+   The lookup order is:
+	temporary_env
+	shell_variables list
+*/
+
+SHELL_VAR *
+find_variable_internal (name, flags)
+     const char *name;
+     int flags;
+{
+  SHELL_VAR *var;
+  int search_tempenv, force_tempenv;
+  VAR_CONTEXT *vc;
+
+  var = (SHELL_VAR *)NULL;
+
+  force_tempenv = (flags & FV_FORCETEMPENV);
+
+  /* If explicitly requested, first look in the temporary environment for
+     the variable.  This allows constructs such as "foo=x eval 'echo $foo'"
+     to get the `exported' value of $foo.  This happens if we are executing
+     a function or builtin, or if we are looking up a variable in a
+     "subshell environment". */
+  search_tempenv = force_tempenv || (expanding_redir == 0 && subshell_environment);
+
+  if (search_tempenv && temporary_env)		
+    var = hash_lookup (name, temporary_env);
+
+  if (var == 0)
+    {
+      if ((flags & FV_SKIPINVISIBLE) == 0)
+	var = var_lookup (name, shell_variables);
+      else
+	{
+	  /* essentially var_lookup expanded inline so we can check for
+	     att_invisible */
+	  for (vc = shell_variables; vc; vc = vc->down)
+	    {
+	      var = hash_lookup (name, vc->table);
+	      if (var && invisible_p (var))
+		var = 0;
+	      if (var)
+		break;
+	    }
+	}
+    }
+
+  if (var == 0)
+    return ((SHELL_VAR *)NULL);
+
+  return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+/* Look up and resolve the chain of nameref variables starting at V all the
+   way to NULL or non-nameref. */
+SHELL_VAR *
+find_variable_nameref (v)
+     SHELL_VAR *v;
+{
+  int level, flags;
+  char *newname;
+  SHELL_VAR *orig, *oldv;
+
+  level = 0;
+  orig = v;
+  while (v && nameref_p (v))
+    {
+      level++;
+      if (level > NAMEREF_MAX)
+	return ((SHELL_VAR *)0);	/* error message here? */
+      newname = nameref_cell (v);
+      if (newname == 0 || *newname == '\0')
+	return ((SHELL_VAR *)0);
+      oldv = v;
+      flags = 0;
+      if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+	flags |= FV_FORCETEMPENV;
+      /* We don't handle array subscripts here. */
+      v = find_variable_internal (newname, flags);
+      if (v == orig || v == oldv)
+	{
+	  internal_warning (_("%s: circular name reference"), orig->name);
+#if 1
+	  /* XXX - provisional change - circular refs go to
+	     global scope for resolution, without namerefs. */
+	  if (variable_context && v->context)
+	    return (find_global_variable_noref (v->name));
+	  else
+#endif
+	  return ((SHELL_VAR *)0);
+	}
+    }
+  return v;
+}
+
+/* Resolve the chain of nameref variables for NAME.  XXX - could change later */
+SHELL_VAR *
+find_variable_last_nameref (name, vflags)
+     const char *name;
+     int vflags;
+{
+  SHELL_VAR *v, *nv;
+  char *newname;
+  int level, flags;
+
+  nv = v = find_variable_noref (name);
+  level = 0;
+  while (v && nameref_p (v))
+    {
+      level++;
+      if (level > NAMEREF_MAX)
+        return ((SHELL_VAR *)0);	/* error message here? */
+      newname = nameref_cell (v);
+      if (newname == 0 || *newname == '\0')
+	return ((vflags && invisible_p (v)) ? v : (SHELL_VAR *)0);
+      nv = v;
+      flags = 0;
+      if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+	flags |= FV_FORCETEMPENV;
+      /* We don't accommodate array subscripts here. */
+      v = find_variable_internal (newname, flags);
+    }
+  return nv;
+}
+
+/* Resolve the chain of nameref variables for NAME.  XXX - could change later */
+SHELL_VAR *
+find_global_variable_last_nameref (name, vflags)
+     const char *name;
+     int vflags;
+{
+  SHELL_VAR *v, *nv;
+  char *newname;
+  int level;
+
+  nv = v = find_global_variable_noref (name);
+  level = 0;
+  while (v && nameref_p (v))
+    {
+      level++;
+      if (level > NAMEREF_MAX)
+        return ((SHELL_VAR *)0);	/* error message here? */
+      newname = nameref_cell (v);
+      if (newname == 0 || *newname == '\0')
+	return ((vflags && invisible_p (v)) ? v : (SHELL_VAR *)0);
+      nv = v;
+      /* We don't accommodate array subscripts here. */
+      v = find_global_variable_noref (newname);
+    }
+  return nv;
+}
+
+static SHELL_VAR *
+find_nameref_at_context (v, vc)
+     SHELL_VAR *v;
+     VAR_CONTEXT *vc;
+{
+  SHELL_VAR *nv, *nv2;
+  char *newname;
+  int level;
+
+  nv = v;
+  level = 1;
+  while (nv && nameref_p (nv))
+    {
+      level++;
+      if (level > NAMEREF_MAX)
+        return (&nameref_maxloop_value);
+      newname = nameref_cell (nv);
+      if (newname == 0 || *newname == '\0')
+        return ((SHELL_VAR *)NULL);      
+      nv2 = hash_lookup (newname, vc->table);
+      if (nv2 == 0)
+        break;
+      nv = nv2;
+    }
+  return nv;
+}
+
+/* Do nameref resolution from the VC, which is the local context for some
+   function or builtin, `up' the chain to the global variables context.  If
+   NVCP is not NULL, return the variable context where we finally ended the
+   nameref resolution (so the bind_variable_internal can use the correct
+   variable context and hash table). */
+static SHELL_VAR *
+find_variable_nameref_context (v, vc, nvcp)
+     SHELL_VAR *v;
+     VAR_CONTEXT *vc;
+     VAR_CONTEXT **nvcp;
+{
+  SHELL_VAR *nv, *nv2;
+  VAR_CONTEXT *nvc;
+
+  /* Look starting at the current context all the way `up' */
+  for (nv = v, nvc = vc; nvc; nvc = nvc->down)
+    {
+      nv2 = find_nameref_at_context (nv, nvc);
+      if (nv2 == &nameref_maxloop_value)
+	return (nv2);			/* XXX */
+      if (nv2 == 0)
+        continue;
+      nv = nv2;
+      if (*nvcp)
+        *nvcp = nvc;
+      if (nameref_p (nv) == 0)
+        break;
+    }
+  return (nameref_p (nv) ? (SHELL_VAR *)NULL : nv);
+}
+
+/* Do nameref resolution from the VC, which is the local context for some
+   function or builtin, `up' the chain to the global variables context.  If
+   NVCP is not NULL, return the variable context where we finally ended the
+   nameref resolution (so the bind_variable_internal can use the correct
+   variable context and hash table). */
+static SHELL_VAR *
+find_variable_last_nameref_context (v, vc, nvcp)
+     SHELL_VAR *v;
+     VAR_CONTEXT *vc;
+     VAR_CONTEXT **nvcp;
+{
+  SHELL_VAR *nv, *nv2;
+  VAR_CONTEXT *nvc;
+
+  /* Look starting at the current context all the way `up' */
+  for (nv = v, nvc = vc; nvc; nvc = nvc->down)
+    {
+      nv2 = find_nameref_at_context (nv, nvc);
+      if (nv2 == &nameref_maxloop_value)
+	return (nv2);			/* XXX */
+      if (nv2 == 0)
+	continue;
+      nv = nv2;
+      if (*nvcp)
+        *nvcp = nvc;
+    }
+  return (nameref_p (nv) ? nv : (SHELL_VAR *)NULL);
+}
+
+SHELL_VAR *
+find_variable_nameref_for_create (name, flags)
+     const char *name;
+     int flags;
+{
+  SHELL_VAR *var;
+
+  /* See if we have a nameref pointing to a variable that hasn't been
+     created yet. */
+  var = find_variable_last_nameref (name, 1);
+  if ((flags&1) && var && nameref_p (var) && invisible_p (var))
+    {
+      internal_warning (_("%s: removing nameref attribute"), name);
+      VUNSETATTR (var, att_nameref);
+    }
+  if (var && nameref_p (var))
+    {
+      if (legal_identifier (nameref_cell (var)) == 0)
+	{
+	  sh_invalidid (nameref_cell (var) ? nameref_cell (var) : "");
+	  return ((SHELL_VAR *)INVALID_NAMEREF_VALUE);
+	}
+    }
+  return (var);
+}
+
+SHELL_VAR *
+find_variable_nameref_for_assignment (name, flags)
+     const char *name;
+     int flags;
+{
+  SHELL_VAR *var;
+
+  /* See if we have a nameref pointing to a variable that hasn't been
+     created yet. */
+  var = find_variable_last_nameref (name, 1);
+  if (var && nameref_p (var) && invisible_p (var))	/* XXX - flags */
+    {
+      internal_warning (_("%s: removing nameref attribute"), name);
+      VUNSETATTR (var, att_nameref);
+    }
+  if (var && nameref_p (var))
+    {
+      if (valid_nameref_value (nameref_cell (var), 1) == 0)
+	{
+	  sh_invalidid (nameref_cell (var) ? nameref_cell (var) : "");
+	  return ((SHELL_VAR *)INVALID_NAMEREF_VALUE);
+	}
+    }
+  return (var);
+}
+
+/* If find_variable (name) returns NULL, check that it's not a nameref
+   referencing a variable that doesn't exist. If it is, return the new
+   name. If not, return the original name. Kind of like the previous
+   function, but dealing strictly with names. This takes assignment flags
+   so it can deal with the various assignment modes used by `declare'. */
+char *
+nameref_transform_name (name, flags)
+     char *name;
+     int flags;
+{
+  SHELL_VAR *v;
+  char *newname;
+
+  v = 0;
+  if (flags & ASS_MKLOCAL)
+    {
+      v = find_variable_last_nameref (name, 1);
+      /* If we're making local variables, only follow namerefs that point to
+	 non-existent variables at the same variable context. */
+      if (v && v->context != variable_context)
+	v = 0;
+    }
+  else if (flags & ASS_MKGLOBAL)
+    v = (flags & ASS_CHKLOCAL) ? find_variable_last_nameref (name, 1)
+			       : find_global_variable_last_nameref (name, 1);
+  if (v && nameref_p (v) && valid_nameref_value (nameref_cell (v), 1))
+    return nameref_cell (v);
+  return name;
+}
+
+/* Find a variable, forcing a search of the temporary environment first */
+SHELL_VAR *
+find_variable_tempenv (name)
+     const char *name;
+{
+  SHELL_VAR *var;
+
+  var = find_variable_internal (name, FV_FORCETEMPENV);
+  if (var && nameref_p (var))
+    var = find_variable_nameref (var);
+  return (var);
+}
+
+/* Find a variable, not forcing a search of the temporary environment first */
+SHELL_VAR *
+find_variable_notempenv (name)
+     const char *name;
+{
+  SHELL_VAR *var;
+
+  var = find_variable_internal (name, 0);
+  if (var && nameref_p (var))
+    var = find_variable_nameref (var);
+  return (var);
+}
+
+SHELL_VAR *
+find_global_variable (name)
+     const char *name;
+{
+  SHELL_VAR *var;
+
+  var = var_lookup (name, global_variables);
+  if (var && nameref_p (var))
+    var = find_variable_nameref (var);	/* XXX - find_global_variable_noref? */
+
+  if (var == 0)
+    return ((SHELL_VAR *)NULL);
+
+  return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+SHELL_VAR *
+find_global_variable_noref (name)
+     const char *name;
+{
+  SHELL_VAR *var;
+
+  var = var_lookup (name, global_variables);
+
+  if (var == 0)
+    return ((SHELL_VAR *)NULL);
+
+  return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+SHELL_VAR *
+find_shell_variable (name)
+     const char *name;
+{
+  SHELL_VAR *var;
+
+  var = var_lookup (name, shell_variables);
+  if (var && nameref_p (var))
+    var = find_variable_nameref (var);
+
+  if (var == 0)
+    return ((SHELL_VAR *)NULL);
+
+  return (var->dynamic_value ? (*(var->dynamic_value)) (var) : var);
+}
+
+/* Look up the variable entry named NAME.  Returns the entry or NULL. */
+SHELL_VAR *
+find_variable (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+  int flags;
+
+  last_table_searched = 0;
+  flags = 0;
+  if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+    flags |= FV_FORCETEMPENV;
+  v = find_variable_internal (name, flags);
+  if (v && nameref_p (v))
+    v = find_variable_nameref (v);
+  return v;
+}
+
+/* Find the first instance of NAME in the variable context chain; return first
+   one found without att_invisible set; return 0 if no non-invisible instances
+   found. */
+SHELL_VAR *
+find_variable_no_invisible (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+  int flags;
+
+  last_table_searched = 0;
+  flags = FV_SKIPINVISIBLE;
+  if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+    flags |= FV_FORCETEMPENV;
+  v = find_variable_internal (name, flags);
+  if (v && nameref_p (v))
+    v = find_variable_nameref (v);
+  return v;
+}
+
+/* Find the first instance of NAME in the variable context chain; return first
+   one found even if att_invisible set. */
+SHELL_VAR *
+find_variable_for_assignment (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+  int flags;
+
+  last_table_searched = 0;
+  flags = 0;
+  if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+    flags |= FV_FORCETEMPENV;
+  v = find_variable_internal (name, flags);
+  if (v && nameref_p (v))
+    v = find_variable_nameref (v);
+  return v;
+}
+
+SHELL_VAR *
+find_variable_noref (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+  int flags;
+
+  flags = 0;
+  if (expanding_redir == 0 && (assigning_in_environment || executing_builtin))
+    flags |= FV_FORCETEMPENV;
+  v = find_variable_internal (name, flags);
+  return v;
+}
+
+/* Look up the function entry whose name matches STRING.
+   Returns the entry or NULL. */
+SHELL_VAR *
+find_function (name)
+     const char *name;
+{
+  return (hash_lookup (name, shell_functions));
+}
+
+/* Find the function definition for the shell function named NAME.  Returns
+   the entry or NULL. */
+FUNCTION_DEF *
+find_function_def (name)
+     const char *name;
+{
+#if defined (DEBUGGER)
+  return ((FUNCTION_DEF *)hash_lookup (name, shell_function_defs));
+#else
+  return ((FUNCTION_DEF *)0);
+#endif
+}
+
+/* Return the value of VAR.  VAR is assumed to have been the result of a
+   lookup without any subscript, if arrays are compiled into the shell. */
+char *
+get_variable_value (var)
+     SHELL_VAR *var;
+{
+  if (var == 0)
+    return ((char *)NULL);
+#if defined (ARRAY_VARS)
+  else if (array_p (var))
+    return (array_reference (array_cell (var), 0));
+  else if (assoc_p (var))
+    return (assoc_reference (assoc_cell (var), "0"));
+#endif
+  else
+    return (value_cell (var));
+}
+
+/* Return the string value of a variable.  Return NULL if the variable
+   doesn't exist.  Don't cons a new string.  This is a potential memory
+   leak if the variable is found in the temporary environment, but doesn't
+   leak in practice.  Since functions and variables have separate name
+   spaces, returns NULL if var_name is a shell function only. */
+char *
+get_string_value (var_name)
+     const char *var_name;
+{
+  SHELL_VAR *var;
+
+  var = find_variable (var_name);
+  return ((var) ? get_variable_value (var) : (char *)NULL);
+}
+
+/* This is present for use by the tilde and readline libraries. */
+char *
+sh_get_env_value (v)
+     const char *v;
+{
+  return get_string_value (v);
+}
+
+/* **************************************************************** */
+/*								    */
+/*		  Creating and setting variables		    */
+/*								    */
+/* **************************************************************** */
+
+static int
+var_sametype (v1, v2)
+     SHELL_VAR *v1;
+     SHELL_VAR *v2;
+{
+  if (v1 == 0 || v2 == 0)
+    return 0;
+#if defined (ARRAY_VARS)
+  else if (assoc_p (v1) && assoc_p (v2))
+    return 1;
+  else if (array_p (v1) && array_p (v2))
+    return 1;
+  else if (array_p (v1) || array_p (v2))
+    return 0;
+  else if (assoc_p (v1) || assoc_p (v2))
+    return 0;
+#endif
+  else
+    return 1;
+}
+
+int
+validate_inherited_value (var, type)
+     SHELL_VAR *var;
+     int type;
+{
+#if defined (ARRAY_VARS)
+  if (type == att_array && assoc_p (var))
+    return 0;
+  else if (type == att_assoc && array_p (var))
+    return 0;
+  else
+#endif
+  return 1;	/* should we run convert_var_to_array here or let the caller? */
+}
+
+/* Set NAME to VALUE if NAME has no value. */
+SHELL_VAR *
+set_if_not (name, value)
+     char *name, *value;
+{
+  SHELL_VAR *v;
+
+  if (shell_variables == 0)
+    create_variable_tables ();
+
+  v = find_variable (name);
+  if (v == 0)
+    v = bind_variable_internal (name, value, global_variables->table, HASH_NOSRCH, 0);
+  return (v);
+}
+
+/* Create a local variable referenced by NAME. */
+SHELL_VAR *
+make_local_variable (name, flags)
+     const char *name;
+     int flags;
+{
+  SHELL_VAR *new_var, *old_var, *old_ref;
+  VAR_CONTEXT *vc;
+  int was_tmpvar;
+  char *old_value;
+
+  /* We don't want to follow the nameref chain when making local variables; we
+     just want to create them. */
+  old_ref = find_variable_noref (name);
+  if (old_ref && nameref_p (old_ref) == 0)
+    old_ref = 0;
+  /* local foo; local foo;  is a no-op. */
+  old_var = find_variable (name);
+  if (old_ref == 0 && old_var && local_p (old_var) && old_var->context == variable_context)
+    return (old_var);
+
+  /* local -n foo; local -n foo;  is a no-op. */
+  if (old_ref && local_p (old_ref) && old_ref->context == variable_context)
+    return (old_ref);
+
+  /* From here on, we want to use the refvar, not the variable it references */
+  if (old_ref)
+    old_var = old_ref;
+
+  was_tmpvar = old_var && tempvar_p (old_var);
+  /* If we're making a local variable in a shell function, the temporary env
+     has already been merged into the function's variable context stack.  We
+     can assume that a temporary var in the same context appears in the same
+     VAR_CONTEXT and can safely be returned without creating a new variable
+     (which results in duplicate names in the same VAR_CONTEXT->table */
+  /* We can't just test tmpvar_p because variables in the temporary env given
+     to a shell function appear in the function's local variable VAR_CONTEXT
+     but retain their tempvar attribute.  We want temporary variables that are
+     found in temporary_env, hence the test for last_table_searched, which is
+     set in hash_lookup and only (so far) checked here. */
+  if (was_tmpvar && old_var->context == variable_context && last_table_searched != temporary_env)
+    {
+      VUNSETATTR (old_var, att_invisible);	/* XXX */
+      /* We still want to flag this variable as local, though, and set things
+         up so that it gets treated as a local variable. */
+      new_var = old_var;
+      /* Since we found the variable in a temporary environment, this will
+	 succeed. */
+      for (vc = shell_variables; vc; vc = vc->down)
+	if (vc_isfuncenv (vc) && vc->scope == variable_context)
+	  break;
+      goto set_local_var_flags;
+
+      return (old_var);
+    }
+
+  /* If we want to change to "inherit the old variable's value" semantics,
+     here is where to save the old value. */
+  old_value = was_tmpvar ? value_cell (old_var) : (char *)NULL;
+
+  for (vc = shell_variables; vc; vc = vc->down)
+    if (vc_isfuncenv (vc) && vc->scope == variable_context)
+      break;
+
+  if (vc == 0)
+    {
+      internal_error (_("make_local_variable: no function context at current scope"));
+      return ((SHELL_VAR *)NULL);
+    }
+  else if (vc->table == 0)
+    vc->table = hash_create (TEMPENV_HASH_BUCKETS);
+
+  /* Since this is called only from the local/declare/typeset code, we can
+     call builtin_error here without worry (of course, it will also work
+     for anything that sets this_command_name).  Variables with the `noassign'
+     attribute may not be made local.  The test against old_var's context
+     level is to disallow local copies of readonly global variables (since I
+     believe that this could be a security hole).  Readonly copies of calling
+     function local variables are OK. */
+  if (old_var && (noassign_p (old_var) ||
+		 (readonly_p (old_var) && old_var->context == 0)))
+    {
+      if (readonly_p (old_var))
+	sh_readonly (name);
+      else if (noassign_p (old_var))
+	builtin_error (_("%s: variable may not be assigned value"), name);
+#if 0
+      /* Let noassign variables through with a warning */
+      if (readonly_p (old_var))
+#endif
+	return ((SHELL_VAR *)NULL);
+    }
+
+  if (old_var == 0)
+    new_var = make_new_variable (name, vc->table);
+  else
+    {
+      new_var = make_new_variable (name, vc->table);
+
+      /* If we found this variable in one of the temporary environments,
+	 inherit its value.  Watch to see if this causes problems with
+	 things like `x=4 local x'. XXX - see above for temporary env
+	 variables with the same context level as variable_context */
+      /* XXX - we should only do this if the variable is not an array. */
+      /* If we want to change the local variable semantics to "inherit
+	 the old variable's value" here is where to set it.  And we would
+	 need to use copy_variable (currently unused) to do it for all
+	 possible variable values. */
+      if (was_tmpvar)
+	var_setvalue (new_var, savestring (old_value));
+      else if (localvar_inherit || (flags & MKLOC_INHERIT))
+	{
+	  /* This may not make sense for nameref variables that are shadowing
+	     variables with the same name, but we don't know that yet. */
+#if defined (ARRAY_VARS)
+	  if (assoc_p (old_var))
+	    var_setassoc (new_var, assoc_copy (assoc_cell (old_var)));
+	  else if (array_p (old_var))
+	    var_setarray (new_var, array_copy (array_cell (old_var)));
+	  else if (value_cell (old_var))
+#else
+	  if (value_cell (old_var))
+#endif
+	    var_setvalue (new_var, savestring (value_cell (old_var)));
+	  else
+	    var_setvalue (new_var, (char *)NULL);
+	}
+
+      if (localvar_inherit || (flags & MKLOC_INHERIT))
+	{
+	  /* It doesn't make sense to inherit the nameref attribute */
+	  new_var->attributes = old_var->attributes & ~att_nameref;
+	  new_var->dynamic_value = old_var->dynamic_value;
+	  new_var->assign_func = old_var->assign_func;
+	}
+      else
+	/* We inherit the export attribute, but no others. */
+	new_var->attributes = exported_p (old_var) ? att_exported : 0;
+    }
+
+set_local_var_flags:
+  vc->flags |= VC_HASLOCAL;
+
+  new_var->context = variable_context;
+  VSETATTR (new_var, att_local);
+
+  if (ifsname (name))
+    setifs (new_var);
+
+  /* value_cell will be 0 if localvar_inherit == 0 or there was no old variable
+     with the same name or the old variable was invisible */
+  if (was_tmpvar == 0 && value_cell (new_var) == 0)
+    VSETATTR (new_var, att_invisible);	/* XXX */
+  return (new_var);
+}
+
+/* Create a new shell variable with name NAME. */
+static SHELL_VAR *
+new_shell_variable (name)
+     const char *name;
+{
+  SHELL_VAR *entry;
+
+  entry = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
+
+  entry->name = savestring (name);
+  var_setvalue (entry, (char *)NULL);
+  CLEAR_EXPORTSTR (entry);
+
+  entry->dynamic_value = (sh_var_value_func_t *)NULL;
+  entry->assign_func = (sh_var_assign_func_t *)NULL;
+
+  entry->attributes = 0;
+
+  /* Always assume variables are to be made at toplevel!
+     make_local_variable has the responsibility of changing the
+     variable context. */
+  entry->context = 0;
+
+  return (entry);
+}
+
+/* Create a new shell variable with name NAME and add it to the hash table
+   TABLE. */
+static SHELL_VAR *
+make_new_variable (name, table)
+     const char *name;
+     HASH_TABLE *table;
+{
+  SHELL_VAR *entry;
+  BUCKET_CONTENTS *elt;
+
+  entry = new_shell_variable (name);
+
+  /* Make sure we have a shell_variables hash table to add to. */
+  if (shell_variables == 0)
+    create_variable_tables ();
+
+  elt = hash_insert (savestring (name), table, HASH_NOSRCH);
+  elt->data = (PTR_T)entry;
+
+  return entry;
+}
+
+#if defined (ARRAY_VARS)
+SHELL_VAR *
+make_new_array_variable (name)
+     char *name;
+{
+  SHELL_VAR *entry;
+  ARRAY *array;
+
+  entry = make_new_variable (name, global_variables->table);
+  array = array_create ();
+
+  var_setarray (entry, array);
+  VSETATTR (entry, att_array);
+  return entry;
+}
+
+SHELL_VAR *
+make_local_array_variable (name, flags)
+     char *name;
+     int flags;
+{
+  SHELL_VAR *var;
+  ARRAY *array;
+  int assoc_ok;
+
+  assoc_ok = flags & MKLOC_ASSOCOK;
+
+  var = make_local_variable (name, flags & MKLOC_INHERIT);	/* XXX for now */
+  /* If ASSOC_OK is non-zero, assume that we are ok with letting an assoc
+     variable return to the caller without converting it. The caller will
+     either flag an error or do the conversion itself. */
+  if (var == 0 || array_p (var) || (assoc_ok && assoc_p (var)))
+    return var;
+
+  /* Validate any value we inherited from a variable instance at a previous
+     scope and discard anything that's invalid. */
+  if (localvar_inherit && assoc_p (var))
+    {
+      internal_warning (_("%s: cannot inherit value from incompatible type"), name);
+      VUNSETATTR (var, att_assoc);
+      dispose_variable_value (var);
+      array = array_create ();
+      var_setarray (var, array);
+    }
+  else if (localvar_inherit)
+    var = convert_var_to_array (var);		/* XXX */
+  else
+    {
+      dispose_variable_value (var);
+      array = array_create ();
+      var_setarray (var, array);
+    }
+
+  VSETATTR (var, att_array);
+  return var;
+}
+
+SHELL_VAR *
+make_new_assoc_variable (name)
+     char *name;
+{
+  SHELL_VAR *entry;
+  HASH_TABLE *hash;
+
+  entry = make_new_variable (name, global_variables->table);
+  hash = assoc_create (ASSOC_HASH_BUCKETS);
+
+  var_setassoc (entry, hash);
+  VSETATTR (entry, att_assoc);
+  return entry;
+}
+
+SHELL_VAR *
+make_local_assoc_variable (name, flags)
+     char *name;
+     int flags;
+{
+  SHELL_VAR *var;
+  HASH_TABLE *hash;
+  int array_ok;
+
+  array_ok = flags & MKLOC_ARRAYOK;
+
+  var = make_local_variable (name, flags & MKLOC_INHERIT);	/* XXX for now */
+  /* If ARRAY_OK is non-zero, assume that we are ok with letting an array
+     variable return to the caller without converting it. The caller will
+     either flag an error or do the conversion itself. */
+  if (var == 0 || assoc_p (var) || (array_ok && array_p (var)))
+    return var;
+
+  /* Validate any value we inherited from a variable instance at a previous
+     scope and discard anything that's invalid. */
+  if (localvar_inherit && array_p (var))
+    {
+      internal_warning (_("%s: cannot inherit value from incompatible type"), name);
+      VUNSETATTR (var, att_array);
+      dispose_variable_value (var);
+      hash = assoc_create (ASSOC_HASH_BUCKETS);
+      var_setassoc (var, hash);
+    }
+  else if (localvar_inherit)
+    var = convert_var_to_assoc (var);		/* XXX */
+  else
+    {
+      dispose_variable_value (var);
+      hash = assoc_create (ASSOC_HASH_BUCKETS);
+      var_setassoc (var, hash);
+    }
+
+  VSETATTR (var, att_assoc);
+  return var;
+}
+#endif
+
+char *
+make_variable_value (var, value, flags)
+     SHELL_VAR *var;
+     char *value;
+     int flags;
+{
+  char *retval, *oval;
+  intmax_t lval, rval;
+  int expok, olen, op;
+
+  /* If this variable has had its type set to integer (via `declare -i'),
+     then do expression evaluation on it and store the result.  The
+     functions in expr.c (evalexp()) and bind_int_variable() are responsible
+     for turning off the integer flag if they don't want further
+     evaluation done.  Callers that find it inconvenient to do this can set
+     the ASS_NOEVAL flag.  For the special case of arithmetic expression
+     evaluation, the caller can set ASS_NOLONGJMP to avoid jumping out to
+     top_level. */
+  if ((flags & ASS_NOEVAL) == 0 && integer_p (var))
+    {
+      if (flags & ASS_APPEND)
+	{
+	  oval = value_cell (var);
+	  lval = evalexp (oval, 0, &expok);	/* ksh93 seems to do this */
+	  if (expok == 0)
+	    {
+	      if (flags & ASS_NOLONGJMP)
+		goto make_value;
+	      else
+		{
+		  top_level_cleanup ();
+		  jump_to_top_level (DISCARD);
+		}
+	    }
+	}
+      rval = evalexp (value, 0, &expok);
+      if (expok == 0)
+	{
+	  if (flags & ASS_NOLONGJMP)
+	    goto make_value;
+	  else
+	    {
+	      top_level_cleanup ();
+	      jump_to_top_level (DISCARD);
+	    }
+	}
+      /* This can be fooled if the variable's value changes while evaluating
+	 `rval'.  We can change it if we move the evaluation of lval to here. */
+      if (flags & ASS_APPEND)
+	rval += lval;
+      retval = itos (rval);
+    }
+#if defined (CASEMOD_ATTRS)
+  else if ((flags & ASS_NOEVAL) == 0 && (capcase_p (var) || uppercase_p (var) || lowercase_p (var)))
+    {
+      if (flags & ASS_APPEND)
+	{
+	  oval = get_variable_value (var);
+	  if (oval == 0)	/* paranoia */
+	    oval = "";
+	  olen = STRLEN (oval);
+	  retval = (char *)xmalloc (olen + (value ? STRLEN (value) : 0) + 1);
+	  strcpy (retval, oval);
+	  if (value)
+	    strcpy (retval+olen, value);
+	}
+      else if (*value)
+	retval = savestring (value);
+      else
+	{
+	  retval = (char *)xmalloc (1);
+	  retval[0] = '\0';
+	}
+      op = capcase_p (var) ? CASE_CAPITALIZE
+			 : (uppercase_p (var) ? CASE_UPPER : CASE_LOWER);
+      oval = sh_modcase (retval, (char *)0, op);
+      free (retval);
+      retval = oval;
+    }
+#endif /* CASEMOD_ATTRS */
+  else if (value)
+    {
+make_value:
+      if (flags & ASS_APPEND)
+	{
+	  oval = get_variable_value (var);
+	  if (oval == 0)	/* paranoia */
+	    oval = "";
+	  olen = STRLEN (oval);
+	  retval = (char *)xmalloc (olen + (value ? STRLEN (value) : 0) + 1);
+	  strcpy (retval, oval);
+	  if (value)
+	    strcpy (retval+olen, value);
+	}
+      else if (*value)
+	retval = savestring (value);
+      else
+	{
+	  retval = (char *)xmalloc (1);
+	  retval[0] = '\0';
+	}
+    }
+  else
+    retval = (char *)NULL;
+
+  return retval;
+}
+
+/* If we can optimize appending to string variables, say so */
+static int
+can_optimize_assignment (entry, value, aflags)
+     SHELL_VAR *entry;
+     char *value;
+     int aflags;
+{
+  if ((aflags & ASS_APPEND) == 0)
+    return 0;
+#if defined (ARRAY_VARS)
+  if (array_p (entry) || assoc_p (entry))
+    return 0;
+#endif
+  if (integer_p (entry) || uppercase_p (entry) || lowercase_p (entry) || capcase_p (entry))
+    return 0;
+  if (readonly_p (entry) || noassign_p (entry))
+    return 0;
+  return 1;
+}
+
+/* right now we optimize appends to string variables */
+static SHELL_VAR *
+optimized_assignment (entry, value, aflags)
+     SHELL_VAR *entry;
+     char *value;
+     int aflags;
+{
+  size_t len, vlen;
+  char *v, *new;
+
+  v = value_cell (entry);
+  len = STRLEN (v);
+  vlen = STRLEN (value);
+
+  new = (char *)xrealloc (v, len + vlen + 8);	/* for now */
+  if (vlen == 1)
+    {
+      new[len] = *value;
+      new[len+1] = '\0';
+    }
+  else
+    strcpy (new + len, value);
+  var_setvalue (entry, new);
+  return entry;
+}
+
+/* Bind a variable NAME to VALUE in the HASH_TABLE TABLE, which may be the
+   temporary environment (but usually is not).  HFLAGS controls how NAME
+   is looked up in TABLE; AFLAGS controls how VALUE is assigned */
+static SHELL_VAR *
+bind_variable_internal (name, value, table, hflags, aflags)
+     const char *name;
+     char *value;
+     HASH_TABLE *table;
+     int hflags, aflags;
+{
+  char *newval, *tname;
+  SHELL_VAR *entry, *tentry;
+
+  entry = (hflags & HASH_NOSRCH) ? (SHELL_VAR *)NULL : hash_lookup (name, table);
+  /* Follow the nameref chain here if this is the global variables table */
+  if (entry && nameref_p (entry) && (invisible_p (entry) == 0) && table == global_variables->table)
+    {
+      entry = find_global_variable (entry->name);
+      /* Let's see if we have a nameref referencing a variable that hasn't yet
+	 been created. */
+      if (entry == 0)
+	entry = find_variable_last_nameref (name, 0);	/* XXX */
+      if (entry == 0)					/* just in case */
+        return (entry);
+    }
+
+  /* The first clause handles `declare -n ref; ref=x;' or `declare -n ref;
+     declare -n ref' */
+  if (entry && invisible_p (entry) && nameref_p (entry))
+    {
+      if ((aflags & ASS_FORCE) == 0 && value && valid_nameref_value (value, 0) == 0)
+	{
+	  sh_invalidid (value);
+	  return ((SHELL_VAR *)NULL);
+	}
+      goto assign_value;
+    }
+  else if (entry && nameref_p (entry))
+    {
+      newval = nameref_cell (entry);	/* XXX - newval can't be NULL here */
+      if (valid_nameref_value (newval, 0) == 0)
+	{
+	  sh_invalidid (newval);
+	  return ((SHELL_VAR *)NULL);
+	}
+#if defined (ARRAY_VARS)
+      /* declare -n foo=x[2] ; foo=bar */
+      if (valid_array_reference (newval, 0))
+	{
+	  tname = array_variable_name (newval, 0, (char **)0, (int *)0);
+	  if (tname && (tentry = find_variable_noref (tname)) && nameref_p (tentry))
+	    {
+	      /* nameref variables can't be arrays */
+	      internal_warning (_("%s: removing nameref attribute"), name_cell (tentry));
+	      FREE (value_cell (tentry));		/* XXX - bash-4.3 compat */
+	      var_setvalue (tentry, (char *)NULL);
+	      VUNSETATTR (tentry, att_nameref);
+	    }
+	  free (tname);
+
+	  /* entry == nameref variable; tentry == array variable;
+	     newval == x[2]; value = bar
+	     We don't need to call make_variable_value here, since
+	     assign_array_element will eventually do it itself based on
+	     newval and aflags. */
+
+	  entry = assign_array_element (newval, value, aflags|ASS_NAMEREF, (array_eltstate_t *)0);
+	  if (entry == 0)
+	    return entry;
+	}
+      else
+#endif
+	{
+	  entry = make_new_variable (newval, table);
+	  var_setvalue (entry, make_variable_value (entry, value, aflags));
+	}
+    }
+  else if (entry == 0)
+    {
+      entry = make_new_variable (name, table);
+      var_setvalue (entry, make_variable_value (entry, value, aflags)); /* XXX */
+    }
+  else if (entry->assign_func)	/* array vars have assign functions now */
+    {
+      if ((readonly_p (entry) && (aflags & ASS_FORCE) == 0) || noassign_p (entry))
+	{
+	  if (readonly_p (entry))
+	    err_readonly (name_cell (entry));
+	  return (entry);
+	}
+
+      INVALIDATE_EXPORTSTR (entry);
+      newval = (aflags & ASS_APPEND) ? make_variable_value (entry, value, aflags) : value;
+      if (assoc_p (entry))
+	entry = (*(entry->assign_func)) (entry, newval, -1, savestring ("0"));
+      else if (array_p (entry))
+	entry = (*(entry->assign_func)) (entry, newval, 0, 0);
+      else
+	entry = (*(entry->assign_func)) (entry, newval, -1, 0);
+      if (newval != value)
+	free (newval);
+      return (entry);
+    }
+  else
+    {
+assign_value:
+      if ((readonly_p (entry) && (aflags & ASS_FORCE) == 0) || noassign_p (entry))
+	{
+	  if (readonly_p (entry))
+	    err_readonly (name_cell (entry));
+	  return (entry);
+	}
+
+      /* Variables which are bound are visible. */
+      VUNSETATTR (entry, att_invisible);
+
+      /* If we can optimize the assignment, do so and return.  Right now, we
+	 optimize appends to string variables. */
+      if (can_optimize_assignment (entry, value, aflags))
+	{
+	  INVALIDATE_EXPORTSTR (entry);
+	  optimized_assignment (entry, value, aflags);
+
+	  if (mark_modified_vars)
+	    VSETATTR (entry, att_exported);
+
+	  if (exported_p (entry))
+	    array_needs_making = 1;
+
+	  return (entry);
+	}
+
+#if defined (ARRAY_VARS)
+      if (assoc_p (entry) || array_p (entry))
+        newval = make_array_variable_value (entry, 0, "0", value, aflags);
+      else
+#endif
+      newval = make_variable_value (entry, value, aflags);	/* XXX */
+
+      /* Invalidate any cached export string */
+      INVALIDATE_EXPORTSTR (entry);
+
+#if defined (ARRAY_VARS)
+      /* XXX -- this bears looking at again -- XXX */
+      /* If an existing array variable x is being assigned to with x=b or
+	 `read x' or something of that nature, silently convert it to
+	 x[0]=b or `read x[0]'. */
+      if (assoc_p (entry))
+	{
+	  assoc_insert (assoc_cell (entry), savestring ("0"), newval);
+	  free (newval);
+	}
+      else if (array_p (entry))
+	{
+	  array_insert (array_cell (entry), 0, newval);
+	  free (newval);
+	}
+      else
+#endif
+	{
+	  FREE (value_cell (entry));
+	  var_setvalue (entry, newval);
+	}
+    }
+
+  if (mark_modified_vars)
+    VSETATTR (entry, att_exported);
+
+  if (exported_p (entry))
+    array_needs_making = 1;
+
+  return (entry);
+}
+	
+/* Bind a variable NAME to VALUE.  This conses up the name
+   and value strings.  If we have a temporary environment, we bind there
+   first, then we bind into shell_variables. */
+
+SHELL_VAR *
+bind_variable (name, value, flags)
+     const char *name;
+     char *value;
+     int flags;
+{
+  SHELL_VAR *v, *nv;
+  VAR_CONTEXT *vc, *nvc;
+
+  if (shell_variables == 0)
+    create_variable_tables ();
+
+  /* If we have a temporary environment, look there first for the variable,
+     and, if found, modify the value there before modifying it in the
+     shell_variables table.  This allows sourced scripts to modify values
+     given to them in a temporary environment while modifying the variable
+     value that the caller sees. */
+  if (temporary_env && value)		/* XXX - can value be null here? */
+    bind_tempenv_variable (name, value);
+
+  /* XXX -- handle local variables here. */
+  for (vc = shell_variables; vc; vc = vc->down)
+    {
+      if (vc_isfuncenv (vc) || vc_isbltnenv (vc))
+	{
+	  v = hash_lookup (name, vc->table);
+	  nvc = vc;
+	  if (v && nameref_p (v))
+	    {
+	      /* This starts at the context where we found the nameref. If we
+		 want to start the name resolution over again at the original
+		 context, this is where we need to change it */
+	      nv = find_variable_nameref_context (v, vc, &nvc);
+	      if (nv == 0)
+		{
+		  nv = find_variable_last_nameref_context (v, vc, &nvc);
+		  if (nv && nameref_p (nv))
+		    {
+		      /* If this nameref variable doesn't have a value yet,
+			 set the value.  Otherwise, assign using the value as
+			 normal. */
+		      if (nameref_cell (nv) == 0)
+			return (bind_variable_internal (nv->name, value, nvc->table, 0, flags));
+#if defined (ARRAY_VARS)
+		      else if (valid_array_reference (nameref_cell (nv), 0))
+			return (assign_array_element (nameref_cell (nv), value, flags, (array_eltstate_t *)0));
+		      else
+#endif
+		      return (bind_variable_internal (nameref_cell (nv), value, nvc->table, 0, flags));
+		    }
+		  else if (nv == &nameref_maxloop_value)
+		    {
+		      internal_warning (_("%s: circular name reference"), v->name);
+		      return (bind_global_variable (v->name, value, flags));
+		    }
+		  else
+		    v = nv;
+		}
+	      else if (nv == &nameref_maxloop_value)
+		{
+		  internal_warning (_("%s: circular name reference"), v->name);
+		  return (bind_global_variable (v->name, value, flags));
+		}
+	      else
+	        v = nv;
+	    }
+	  if (v)
+	    return (bind_variable_internal (v->name, value, nvc->table, 0, flags));
+	}
+    }
+  /* bind_variable_internal will handle nameref resolution in this case */
+  return (bind_variable_internal (name, value, global_variables->table, 0, flags));
+}
+
+SHELL_VAR *
+bind_global_variable (name, value, flags)
+     const char *name;
+     char *value;
+     int flags;
+{
+  if (shell_variables == 0)
+    create_variable_tables ();
+
+  /* bind_variable_internal will handle nameref resolution in this case */
+  return (bind_variable_internal (name, value, global_variables->table, 0, flags));
+}
+
+static SHELL_VAR *
+bind_invalid_envvar (name, value, flags)
+     const char *name;
+     char *value;
+     int flags;
+{
+  if (invalid_env == 0)
+    invalid_env = hash_create (64);	/* XXX */
+  return (bind_variable_internal (name, value, invalid_env, HASH_NOSRCH, flags));
+}
+
+/* Make VAR, a simple shell variable, have value VALUE.  Once assigned a
+   value, variables are no longer invisible.  This is a duplicate of part
+   of the internals of bind_variable.  If the variable is exported, or
+   all modified variables should be exported, mark the variable for export
+   and note that the export environment needs to be recreated. */
+SHELL_VAR *
+bind_variable_value (var, value, aflags)
+     SHELL_VAR *var;
+     char *value;
+     int aflags;
+{
+  char *t;
+  int invis;
+
+  invis = invisible_p (var);
+  VUNSETATTR (var, att_invisible);
+
+  if (var->assign_func)
+    {
+      /* If we're appending, we need the old value, so use
+	 make_variable_value */
+      t = (aflags & ASS_APPEND) ? make_variable_value (var, value, aflags) : value;
+      (*(var->assign_func)) (var, t, -1, 0);
+      if (t != value && t)
+	free (t);      
+    }
+  else
+    {
+      t = make_variable_value (var, value, aflags);
+      if ((aflags & (ASS_NAMEREF|ASS_FORCE)) == ASS_NAMEREF && check_selfref (name_cell (var), t, 0))
+	{
+	  if (variable_context)
+	    internal_warning (_("%s: circular name reference"), name_cell (var));
+	  else
+	    {
+	      internal_error (_("%s: nameref variable self references not allowed"), name_cell (var));
+	      free (t);
+	      if (invis)
+		VSETATTR (var, att_invisible);	/* XXX */
+	      return ((SHELL_VAR *)NULL);
+	    }
+	}
+      if ((aflags & ASS_NAMEREF) && (valid_nameref_value (t, 0) == 0))
+	{
+	  free (t);
+	  if (invis)
+	    VSETATTR (var, att_invisible);	/* XXX */
+	  return ((SHELL_VAR *)NULL);
+	}
+      FREE (value_cell (var));
+      var_setvalue (var, t);
+    }
+
+  INVALIDATE_EXPORTSTR (var);
+
+  if (mark_modified_vars)
+    VSETATTR (var, att_exported);
+
+  if (exported_p (var))
+    array_needs_making = 1;
+
+  return (var);
+}
+
+/* Bind/create a shell variable with the name LHS to the RHS.
+   This creates or modifies a variable such that it is an integer.
+
+   This used to be in expr.c, but it is here so that all of the
+   variable binding stuff is localized.  Since we don't want any
+   recursive evaluation from bind_variable() (possible without this code,
+   since bind_variable() calls the evaluator for variables with the integer
+   attribute set), we temporarily turn off the integer attribute for each
+   variable we set here, then turn it back on after binding as necessary. */
+
+SHELL_VAR *
+bind_int_variable (lhs, rhs, flags)
+     char *lhs, *rhs;
+     int flags;
+{
+  register SHELL_VAR *v;
+  int isint, isarr, implicitarray, vflags, avflags;
+
+  isint = isarr = implicitarray = 0;
+#if defined (ARRAY_VARS)
+  /* Don't rely on VA_NOEXPAND being 1, set it explicitly */
+  vflags = (flags & ASS_NOEXPAND) ? VA_NOEXPAND : 0;
+  if (flags & ASS_ONEWORD)
+    vflags |= VA_ONEWORD;
+  if (valid_array_reference (lhs, vflags))
+    {
+      isarr = 1;
+      avflags = 0;
+      /* Common code to translate between assignment and reference flags. */
+      if (flags & ASS_NOEXPAND)
+	avflags |= AV_NOEXPAND;
+      if (flags & ASS_ONEWORD)
+	avflags |= AV_ONEWORD;
+      v = array_variable_part (lhs, avflags, (char **)0, (int *)0);
+    }
+  else if (legal_identifier (lhs) == 0)
+    {
+      sh_invalidid (lhs);
+      return ((SHELL_VAR *)NULL);      
+    }
+  else
+#endif
+    v = find_variable (lhs);
+
+  if (v)
+    {
+      isint = integer_p (v);
+      VUNSETATTR (v, att_integer);
+#if defined (ARRAY_VARS)
+      if (array_p (v) && isarr == 0)
+	implicitarray = 1;
+#endif
+    }
+
+#if defined (ARRAY_VARS)
+  if (isarr)
+    v = assign_array_element (lhs, rhs, flags, (array_eltstate_t *)0);
+  else if (implicitarray)
+    v = bind_array_variable (lhs, 0, rhs, 0);	/* XXX - check on flags */
+  else
+#endif
+    v = bind_variable (lhs, rhs, 0);	/* why not use bind_variable_value? */
+
+  if (v)
+    {
+      if (isint)
+	VSETATTR (v, att_integer);
+      VUNSETATTR (v, att_invisible);
+    }
+
+  if (v && nameref_p (v))
+    internal_warning (_("%s: assigning integer to name reference"), lhs);
+     
+  return (v);
+}
+
+SHELL_VAR *
+bind_var_to_int (var, val, flags)
+     char *var;
+     intmax_t val;
+     int flags;
+{
+  char ibuf[INT_STRLEN_BOUND (intmax_t) + 1], *p;
+
+  p = fmtulong (val, 10, ibuf, sizeof (ibuf), 0);
+  return (bind_int_variable (var, p, flags));
+}
+
+/* Do a function binding to a variable.  You pass the name and
+   the command to bind to.  This conses the name and command. */
+SHELL_VAR *
+bind_function (name, value)
+     const char *name;
+     COMMAND *value;
+{
+  SHELL_VAR *entry;
+
+  entry = find_function (name);
+  if (entry == 0)
+    {
+      BUCKET_CONTENTS *elt;
+
+      elt = hash_insert (savestring (name), shell_functions, HASH_NOSRCH);
+      entry = new_shell_variable (name);
+      elt->data = (PTR_T)entry;
+    }
+  else
+    INVALIDATE_EXPORTSTR (entry);
+
+  if (var_isset (entry))
+    dispose_command (function_cell (entry));
+
+  if (value)
+    var_setfunc (entry, copy_command (value));
+  else
+    var_setfunc (entry, 0);
+
+  VSETATTR (entry, att_function);
+
+  if (mark_modified_vars)
+    VSETATTR (entry, att_exported);
+
+  VUNSETATTR (entry, att_invisible);		/* Just to be sure */
+
+  if (exported_p (entry))
+    array_needs_making = 1;
+
+#if defined (PROGRAMMABLE_COMPLETION)
+  set_itemlist_dirty (&it_functions);
+#endif
+
+  return (entry);
+}
+
+#if defined (DEBUGGER)
+/* Bind a function definition, which includes source file and line number
+   information in addition to the command, into the FUNCTION_DEF hash table.
+   If (FLAGS & 1), overwrite any existing definition. If FLAGS == 0, leave
+   any existing definition alone. */
+void
+bind_function_def (name, value, flags)
+     const char *name;
+     FUNCTION_DEF *value;
+     int flags;
+{
+  FUNCTION_DEF *entry;
+  BUCKET_CONTENTS *elt;
+  COMMAND *cmd;
+
+  entry = find_function_def (name);
+  if (entry && (flags & 1))
+    {
+      dispose_function_def_contents (entry);
+      entry = copy_function_def_contents (value, entry);
+    }
+  else if (entry)
+    return;
+  else
+    {
+      cmd = value->command;
+      value->command = 0;
+      entry = copy_function_def (value);
+      value->command = cmd;
+
+      elt = hash_insert (savestring (name), shell_function_defs, HASH_NOSRCH);
+      elt->data = (PTR_T *)entry;
+    }
+}
+#endif /* DEBUGGER */
+
+/* Add STRING, which is of the form foo=bar, to the temporary environment
+   HASH_TABLE (temporary_env).  The functions in execute_cmd.c are
+   responsible for moving the main temporary env to one of the other
+   temporary environments.  The expansion code in subst.c calls this. */
+int
+assign_in_env (word, flags)
+     WORD_DESC *word;
+     int flags;
+{
+  int offset, aflags;
+  char *name, *temp, *value, *newname;
+  SHELL_VAR *var;
+  const char *string;
+
+  string = word->word;
+
+  aflags = 0;
+  offset = assignment (string, 0);
+  newname = name = savestring (string);
+  value = (char *)NULL;
+
+  if (name[offset] == '=')
+    {
+      name[offset] = 0;
+
+      /* don't ignore the `+' when assigning temporary environment */
+      if (name[offset - 1] == '+')
+	{
+	  name[offset - 1] = '\0';
+	  aflags |= ASS_APPEND;
+	}
+
+      if (legal_identifier (name) == 0)
+	{
+	  sh_invalidid (name);
+	  free (name);
+	  return (0);
+	}
+  
+      var = find_variable (name);
+      if (var == 0)
+	{
+	  var = find_variable_last_nameref (name, 1);
+	  /* If we're assigning a value to a nameref variable in the temp
+	     environment, and the value of the nameref is valid for assignment,
+	     but the variable does not already exist, assign to the nameref
+	     target and add the target to the temporary environment.  This is
+	     what ksh93 does */
+	  /* We use 2 in the call to valid_nameref_value because we don't want
+	     to allow array references here at all (newname will be used to
+	     create a variable directly below) */
+	  if (var && nameref_p (var) && valid_nameref_value (nameref_cell (var), 2))
+	    {
+	      newname = nameref_cell (var);
+	      var = 0;		/* don't use it for append */
+	    }
+	}
+      else
+        newname = name_cell (var);	/* no-op if not nameref */
+	  
+      if (var && (readonly_p (var) || noassign_p (var)))
+	{
+	  if (readonly_p (var))
+	    err_readonly (name);
+	  free (name);
+  	  return (0);
+	}
+      temp = name + offset + 1;
+
+      value = expand_assignment_string_to_string (temp, 0);
+
+      if (var && (aflags & ASS_APPEND))
+	{
+	  if (value == 0)
+	    {
+	      value = (char *)xmalloc (1);	/* like do_assignment_internal */
+	      value[0] = '\0';
+	    }
+	  temp = make_variable_value (var, value, aflags);
+	  FREE (value);
+	  value = temp;
+	}
+    }
+
+  if (temporary_env == 0)
+    temporary_env = hash_create (TEMPENV_HASH_BUCKETS);
+
+  var = hash_lookup (newname, temporary_env);
+  if (var == 0)
+    var = make_new_variable (newname, temporary_env);
+  else
+    FREE (value_cell (var));
+
+  if (value == 0)
+    {
+      value = (char *)xmalloc (1);	/* see above */
+      value[0] = '\0';
+    }
+
+  var_setvalue (var, value);
+  var->attributes |= (att_exported|att_tempvar);
+  var->context = variable_context;	/* XXX */
+
+  INVALIDATE_EXPORTSTR (var);
+  var->exportstr = mk_env_string (newname, value, 0);
+
+  array_needs_making = 1;
+
+  if (flags)
+    {
+      if (STREQ (newname, "POSIXLY_CORRECT") || STREQ (newname, "POSIX_PEDANDTIC"))
+	save_posix_options ();		/* XXX one level of saving right now */
+      stupidly_hack_special_variables (newname);
+    }
+
+  if (echo_command_at_execute)
+    /* The Korn shell prints the `+ ' in front of assignment statements,
+	so we do too. */
+    xtrace_print_assignment (name, value, 0, 1);
+
+  free (name);
+  return 1;
+}
+
+/* **************************************************************** */
+/*								    */
+/*			Copying variables			    */
+/*								    */
+/* **************************************************************** */
+
+#ifdef INCLUDE_UNUSED
+/* Copy VAR to a new data structure and return that structure. */
+SHELL_VAR *
+copy_variable (var)
+     SHELL_VAR *var;
+{
+  SHELL_VAR *copy = (SHELL_VAR *)NULL;
+
+  if (var)
+    {
+      copy = (SHELL_VAR *)xmalloc (sizeof (SHELL_VAR));
+
+      copy->attributes = var->attributes;
+      copy->name = savestring (var->name);
+
+      if (function_p (var))
+	var_setfunc (copy, copy_command (function_cell (var)));
+#if defined (ARRAY_VARS)
+      else if (array_p (var))
+	var_setarray (copy, array_copy (array_cell (var)));
+      else if (assoc_p (var))
+	var_setassoc (copy, assoc_copy (assoc_cell (var)));
+#endif
+      else if (nameref_cell (var))	/* XXX - nameref */
+	var_setref (copy, savestring (nameref_cell (var)));
+      else if (value_cell (var))	/* XXX - nameref */
+	var_setvalue (copy, savestring (value_cell (var)));
+      else
+	var_setvalue (copy, (char *)NULL);
+
+      copy->dynamic_value = var->dynamic_value;
+      copy->assign_func = var->assign_func;
+
+      copy->exportstr = COPY_EXPORTSTR (var);
+
+      copy->context = var->context;
+    }
+  return (copy);
+}
+#endif
+
+/* **************************************************************** */
+/*								    */
+/*		  Deleting and unsetting variables		    */
+/*								    */
+/* **************************************************************** */
+
+/* Dispose of the information attached to VAR. */
+static void
+dispose_variable_value (var)
+     SHELL_VAR *var;
+{
+  if (function_p (var))
+    dispose_command (function_cell (var));
+#if defined (ARRAY_VARS)
+  else if (array_p (var))
+    array_dispose (array_cell (var));
+  else if (assoc_p (var))
+    assoc_dispose (assoc_cell (var));
+#endif
+  else if (nameref_p (var))
+    FREE (nameref_cell (var));
+  else
+    FREE (value_cell (var));
+}
+
+void
+dispose_variable (var)
+     SHELL_VAR *var;
+{
+  if (var == 0)
+    return;
+
+  if (nofree_p (var) == 0)
+    dispose_variable_value (var);
+
+  FREE_EXPORTSTR (var);
+
+  free (var->name);
+
+  if (exported_p (var))
+    array_needs_making = 1;
+
+  free (var);
+}
+
+/* Unset the shell variable referenced by NAME.  Unsetting a nameref variable
+   unsets the variable it resolves to but leaves the nameref alone. */
+int
+unbind_variable (name)
+     const char *name;
+{
+  SHELL_VAR *v, *nv;
+  int r;
+
+  v = var_lookup (name, shell_variables);
+  nv = (v && nameref_p (v)) ? find_variable_nameref (v) : (SHELL_VAR *)NULL;
+
+  r = nv ? makunbound (nv->name, shell_variables) : makunbound (name, shell_variables);
+  return r;
+}
+
+/* Unbind NAME, where NAME is assumed to be a nameref variable */
+int
+unbind_nameref (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+
+  v = var_lookup (name, shell_variables);
+  if (v && nameref_p (v))
+    return makunbound (name, shell_variables);
+  return 0;
+}
+
+/* Unbind the first instance of NAME, whether it's a nameref or not */
+int
+unbind_variable_noref (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+
+  v = var_lookup (name, shell_variables);
+  if (v)
+    return makunbound (name, shell_variables);
+  return 0;
+}
+
+int
+unbind_global_variable (name)
+     const char *name;
+{
+  SHELL_VAR *v, *nv;
+  int r;
+
+  v = var_lookup (name, global_variables);
+  /* This starts at the current scope, just like find_global_variable; should we
+     use find_global_variable_nameref here? */
+  nv = (v && nameref_p (v)) ? find_variable_nameref (v) : (SHELL_VAR *)NULL;
+
+  r = nv ? makunbound (nv->name, shell_variables) : makunbound (name, global_variables);
+  return r;
+}
+
+int
+unbind_global_variable_noref (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+
+  v = var_lookup (name, global_variables);
+  if (v)
+    return makunbound (name, global_variables);
+  return 0;
+}
+ 
+int
+check_unbind_variable (name)
+     const char *name;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v && readonly_p (v))
+    {
+      internal_error (_("%s: cannot unset: readonly %s"), name, "variable");
+      return -2;
+    }
+  else if (v && non_unsettable_p (v))
+    {
+      internal_error (_("%s: cannot unset"), name);
+      return -2;
+    }
+  return (unbind_variable (name));
+}
+
+/* Unset the shell function named NAME. */
+int
+unbind_func (name)
+     const char *name;
+{
+  BUCKET_CONTENTS *elt;
+  SHELL_VAR *func;
+
+  elt = hash_remove (name, shell_functions, 0);
+
+  if (elt == 0)
+    return -1;
+
+#if defined (PROGRAMMABLE_COMPLETION)
+  set_itemlist_dirty (&it_functions);
+#endif
+
+  func = (SHELL_VAR *)elt->data;
+  if (func)
+    {
+      if (exported_p (func))
+	array_needs_making++;
+      dispose_variable (func);
+    }
+
+  free (elt->key);
+  free (elt);
+
+  return 0;  
+}
+
+#if defined (DEBUGGER)
+int
+unbind_function_def (name)
+     const char *name;
+{
+  BUCKET_CONTENTS *elt;
+  FUNCTION_DEF *funcdef;
+
+  elt = hash_remove (name, shell_function_defs, 0);
+
+  if (elt == 0)
+    return -1;
+
+  funcdef = (FUNCTION_DEF *)elt->data;
+  if (funcdef)
+    dispose_function_def (funcdef);
+
+  free (elt->key);
+  free (elt);
+
+  return 0;  
+}
+#endif /* DEBUGGER */
+
+int
+delete_var (name, vc)
+     const char *name;
+     VAR_CONTEXT *vc;
+{
+  BUCKET_CONTENTS *elt;
+  SHELL_VAR *old_var;
+  VAR_CONTEXT *v;
+
+  for (elt = (BUCKET_CONTENTS *)NULL, v = vc; v; v = v->down)
+    if (elt = hash_remove (name, v->table, 0))
+      break;
+
+  if (elt == 0)
+    return (-1);
+
+  old_var = (SHELL_VAR *)elt->data;
+  free (elt->key);
+  free (elt);
+
+  dispose_variable (old_var);
+  return (0);
+}
+
+/* Make the variable associated with NAME go away.  HASH_LIST is the
+   hash table from which this variable should be deleted (either
+   shell_variables or shell_functions).
+   Returns non-zero if the variable couldn't be found. */
+int
+makunbound (name, vc)
+     const char *name;
+     VAR_CONTEXT *vc;
+{
+  BUCKET_CONTENTS *elt, *new_elt;
+  SHELL_VAR *old_var;
+  VAR_CONTEXT *v;
+  char *t;
+
+  for (elt = (BUCKET_CONTENTS *)NULL, v = vc; v; v = v->down)
+    if (elt = hash_remove (name, v->table, 0))
+      break;
+
+  if (elt == 0)
+    return (-1);
+
+  old_var = (SHELL_VAR *)elt->data;
+
+  if (old_var && exported_p (old_var))
+    array_needs_making++;
+
+  /* If we're unsetting a local variable and we're still executing inside
+     the function, just mark the variable as invisible.  The function
+     eventually called by pop_var_context() will clean it up later.  This
+     must be done so that if the variable is subsequently assigned a new
+     value inside the function, the `local' attribute is still present.
+     We also need to add it back into the correct hash table. */
+  if (old_var && local_p (old_var) &&
+	(old_var->context == variable_context || (localvar_unset && old_var->context < variable_context)))
+    {
+      if (nofree_p (old_var))
+	var_setvalue (old_var, (char *)NULL);
+#if defined (ARRAY_VARS)
+      else if (array_p (old_var))
+	array_dispose (array_cell (old_var));
+      else if (assoc_p (old_var))
+	assoc_dispose (assoc_cell (old_var));
+#endif
+      else if (nameref_p (old_var))
+	FREE (nameref_cell (old_var));
+      else
+	FREE (value_cell (old_var));
+      /* Reset the attributes.  Preserve the export attribute if the variable
+	 came from a temporary environment.  Make sure it stays local, and
+	 make it invisible. */ 
+      old_var->attributes = (exported_p (old_var) && tempvar_p (old_var)) ? att_exported : 0;
+      VSETATTR (old_var, att_local);
+      VSETATTR (old_var, att_invisible);
+      var_setvalue (old_var, (char *)NULL);
+      INVALIDATE_EXPORTSTR (old_var);
+
+      new_elt = hash_insert (savestring (old_var->name), v->table, 0);
+      new_elt->data = (PTR_T)old_var;
+      stupidly_hack_special_variables (old_var->name);
+
+      free (elt->key);
+      free (elt);
+      return (0);
+    }
+
+  /* Have to save a copy of name here, because it might refer to
+     old_var->name.  If so, stupidly_hack_special_variables will
+     reference freed memory. */
+  t = savestring (name);
+
+  free (elt->key);
+  free (elt);
+
+  dispose_variable (old_var);
+  stupidly_hack_special_variables (t);
+  free (t);
+
+  return (0);
+}
+
+/* Get rid of all of the variables in the current context. */
+void
+kill_all_local_variables ()
+{
+  VAR_CONTEXT *vc;
+
+  for (vc = shell_variables; vc; vc = vc->down)
+    if (vc_isfuncenv (vc) && vc->scope == variable_context)
+      break;
+  if (vc == 0)
+    return;		/* XXX */
+
+  if (vc->table && vc_haslocals (vc))
+    {
+      delete_all_variables (vc->table);
+      hash_dispose (vc->table);
+    }
+  vc->table = (HASH_TABLE *)NULL;
+}
+
+static void
+free_variable_hash_data (data)
+     PTR_T data;
+{
+  SHELL_VAR *var;
+
+  var = (SHELL_VAR *)data;
+  dispose_variable (var);
+}
+
+/* Delete the entire contents of the hash table. */
+void
+delete_all_variables (hashed_vars)
+     HASH_TABLE *hashed_vars;
+{
+  hash_flush (hashed_vars, free_variable_hash_data);
+}
+
+/* **************************************************************** */
+/*								    */
+/*		     Setting variable attributes		    */
+/*								    */
+/* **************************************************************** */
+
+#define FIND_OR_MAKE_VARIABLE(name, entry) \
+  do \
+    { \
+      entry = find_variable (name); \
+      if (!entry) \
+	{ \
+	  entry = bind_variable (name, "", 0); \
+	  if (entry) entry->attributes |= att_invisible; \
+	} \
+    } \
+  while (0)
+
+/* Make the variable associated with NAME be readonly.
+   If NAME does not exist yet, create it. */
+void
+set_var_read_only (name)
+     char *name;
+{
+  SHELL_VAR *entry;
+
+  FIND_OR_MAKE_VARIABLE (name, entry);
+  VSETATTR (entry, att_readonly);
+}
+
+#ifdef INCLUDE_UNUSED
+/* Make the function associated with NAME be readonly.
+   If NAME does not exist, we just punt, like auto_export code below. */
+void
+set_func_read_only (name)
+     const char *name;
+{
+  SHELL_VAR *entry;
+
+  entry = find_function (name);
+  if (entry)
+    VSETATTR (entry, att_readonly);
+}
+
+/* Make the variable associated with NAME be auto-exported.
+   If NAME does not exist yet, create it. */
+void
+set_var_auto_export (name)
+     char *name;
+{
+  SHELL_VAR *entry;
+
+  FIND_OR_MAKE_VARIABLE (name, entry);
+  set_auto_export (entry);
+}
+
+/* Make the function associated with NAME be auto-exported. */
+void
+set_func_auto_export (name)
+     const char *name;
+{
+  SHELL_VAR *entry;
+
+  entry = find_function (name);
+  if (entry)
+    set_auto_export (entry);
+}
+#endif
+
+/* **************************************************************** */
+/*								    */
+/*		     Creating lists of variables		    */
+/*								    */
+/* **************************************************************** */
+
+static VARLIST *
+vlist_alloc (nentries)
+     int nentries;
+{
+  VARLIST  *vlist;
+
+  vlist = (VARLIST *)xmalloc (sizeof (VARLIST));
+  vlist->list = (SHELL_VAR **)xmalloc ((nentries + 1) * sizeof (SHELL_VAR *));
+  vlist->list_size = nentries;
+  vlist->list_len = 0;
+  vlist->list[0] = (SHELL_VAR *)NULL;
+
+  return vlist;
+}
+
+static VARLIST *
+vlist_realloc (vlist, n)
+     VARLIST *vlist;
+     int n;
+{
+  if (vlist == 0)
+    return (vlist = vlist_alloc (n));
+  if (n > vlist->list_size)
+    {
+      vlist->list_size = n;
+      vlist->list = (SHELL_VAR **)xrealloc (vlist->list, (vlist->list_size + 1) * sizeof (SHELL_VAR *));
+    }
+  return vlist;
+}
+
+static void
+vlist_add (vlist, var, flags)
+     VARLIST *vlist;
+     SHELL_VAR *var;
+     int flags;
+{
+  register int i;
+
+  for (i = 0; i < vlist->list_len; i++)
+    if (STREQ (var->name, vlist->list[i]->name))
+      break;
+  if (i < vlist->list_len)
+    return;
+
+  if (i >= vlist->list_size)
+    vlist = vlist_realloc (vlist, vlist->list_size + 16);
+
+  vlist->list[vlist->list_len++] = var;
+  vlist->list[vlist->list_len] = (SHELL_VAR *)NULL;
+}
+
+/* Map FUNCTION over the variables in VAR_HASH_TABLE.  Return an array of the
+   variables for which FUNCTION returns a non-zero value.  A NULL value
+   for FUNCTION means to use all variables. */
+SHELL_VAR **
+map_over (function, vc)
+     sh_var_map_func_t *function;
+     VAR_CONTEXT *vc;
+{
+  VAR_CONTEXT *v;
+  VARLIST *vlist;
+  SHELL_VAR **ret;
+  int nentries;
+
+  for (nentries = 0, v = vc; v; v = v->down)
+    nentries += HASH_ENTRIES (v->table);
+
+  if (nentries == 0)
+    return (SHELL_VAR **)NULL;
+
+  vlist = vlist_alloc (nentries);
+
+  for (v = vc; v; v = v->down)
+    flatten (v->table, function, vlist, 0);
+
+  ret = vlist->list;
+  free (vlist);
+  return ret;
+}
+
+SHELL_VAR **
+map_over_funcs (function)
+     sh_var_map_func_t *function;
+{
+  VARLIST *vlist;
+  SHELL_VAR **ret;
+
+  if (shell_functions == 0 || HASH_ENTRIES (shell_functions) == 0)
+    return ((SHELL_VAR **)NULL);
+
+  vlist = vlist_alloc (HASH_ENTRIES (shell_functions));
+
+  flatten (shell_functions, function, vlist, 0);
+
+  ret = vlist->list;
+  free (vlist);
+  return ret;
+}
+
+/* Flatten VAR_HASH_TABLE, applying FUNC to each member and adding those
+   elements for which FUNC succeeds to VLIST->list.  FLAGS is reserved
+   for future use.  Only unique names are added to VLIST.  If FUNC is
+   NULL, each variable in VAR_HASH_TABLE is added to VLIST.  If VLIST is
+   NULL, FUNC is applied to each SHELL_VAR in VAR_HASH_TABLE.  If VLIST
+   and FUNC are both NULL, nothing happens. */
+static void
+flatten (var_hash_table, func, vlist, flags)
+     HASH_TABLE *var_hash_table;
+     sh_var_map_func_t *func;
+     VARLIST *vlist;
+     int flags;
+{
+  register int i;
+  register BUCKET_CONTENTS *tlist;
+  int r;
+  SHELL_VAR *var;
+
+  if (var_hash_table == 0 || (HASH_ENTRIES (var_hash_table) == 0) || (vlist == 0 && func == 0))
+    return;
+
+  for (i = 0; i < var_hash_table->nbuckets; i++)
+    {
+      for (tlist = hash_items (i, var_hash_table); tlist; tlist = tlist->next)
+	{
+	  var = (SHELL_VAR *)tlist->data;
+
+	  r = func ? (*func) (var) : 1;
+	  if (r && vlist)
+	    vlist_add (vlist, var, flags);
+	}
+    }
+}
+
+void
+sort_variables (array)
+     SHELL_VAR **array;
+{
+  qsort (array, strvec_len ((char **)array), sizeof (SHELL_VAR *), (QSFUNC *)qsort_var_comp);
+}
+
+static int
+qsort_var_comp (var1, var2)
+     SHELL_VAR **var1, **var2;
+{
+  int result;
+
+  if ((result = (*var1)->name[0] - (*var2)->name[0]) == 0)
+    result = strcmp ((*var1)->name, (*var2)->name);
+
+  return (result);
+}
+
+/* Apply FUNC to each variable in SHELL_VARIABLES, adding each one for
+   which FUNC succeeds to an array of SHELL_VAR *s.  Returns the array. */
+static SHELL_VAR **
+vapply (func)
+     sh_var_map_func_t *func;
+{
+  SHELL_VAR **list;
+
+  list = map_over (func, shell_variables);
+  if (list /* && posixly_correct */)
+    sort_variables (list);
+  return (list);
+}
+
+/* Apply FUNC to each variable in SHELL_FUNCTIONS, adding each one for
+   which FUNC succeeds to an array of SHELL_VAR *s.  Returns the array. */
+static SHELL_VAR **
+fapply (func)
+     sh_var_map_func_t *func;
+{
+  SHELL_VAR **list;
+
+  list = map_over_funcs (func);
+  if (list /* && posixly_correct */)
+    sort_variables (list);
+  return (list);
+}
+
+/* Create a NULL terminated array of all the shell variables. */
+SHELL_VAR **
+all_shell_variables ()
+{
+  return (vapply ((sh_var_map_func_t *)NULL));
+}
+
+/* Create a NULL terminated array of all the shell functions. */
+SHELL_VAR **
+all_shell_functions ()
+{
+  return (fapply ((sh_var_map_func_t *)NULL));
+}
+
+static int
+visible_var (var)
+     SHELL_VAR *var;
+{
+  return (invisible_p (var) == 0);
+}
+
+SHELL_VAR **
+all_visible_functions ()
+{
+  return (fapply (visible_var));
+}
+
+SHELL_VAR **
+all_visible_variables ()
+{
+  return (vapply (visible_var));
+}
+
+/* Return non-zero if the variable VAR is visible and exported.  Array
+   variables cannot be exported. */
+static int
+visible_and_exported (var)
+     SHELL_VAR *var;
+{
+  return (invisible_p (var) == 0 && exported_p (var));
+}
+
+/* Candidate variables for the export environment are either valid variables
+   with the export attribute or invalid variables inherited from the initial
+   environment and simply passed through. */
+static int
+export_environment_candidate (var)
+     SHELL_VAR *var;
+{
+  return (exported_p (var) && (invisible_p (var) == 0 || imported_p (var)));
+}
+
+/* Return non-zero if VAR is a local variable in the current context and
+   is exported. */
+static int
+local_and_exported (var)
+     SHELL_VAR *var;
+{
+  return (invisible_p (var) == 0 && local_p (var) && var->context == variable_context && exported_p (var));
+}
+
+SHELL_VAR **
+all_exported_variables ()
+{
+  return (vapply (visible_and_exported));
+}
+
+SHELL_VAR **
+local_exported_variables ()
+{
+  return (vapply (local_and_exported));
+}
+
+static int
+variable_in_context (var)
+     SHELL_VAR *var;
+{
+  return (local_p (var) && var->context == variable_context);
+}
+
+static int
+visible_variable_in_context (var)
+     SHELL_VAR *var;
+{
+  return (invisible_p (var) == 0 && local_p (var) && var->context == variable_context);
+}
+
+SHELL_VAR **
+all_local_variables (visible_only)
+     int visible_only;
+{
+  VARLIST *vlist;
+  SHELL_VAR **ret;
+  VAR_CONTEXT *vc;
+
+  vc = shell_variables;
+  for (vc = shell_variables; vc; vc = vc->down)
+    if (vc_isfuncenv (vc) && vc->scope == variable_context)
+      break;
+
+  if (vc == 0)
+    {
+      internal_error (_("all_local_variables: no function context at current scope"));
+      return (SHELL_VAR **)NULL;
+    }
+  if (vc->table == 0 || HASH_ENTRIES (vc->table) == 0 || vc_haslocals (vc) == 0)
+    return (SHELL_VAR **)NULL;
+    
+  vlist = vlist_alloc (HASH_ENTRIES (vc->table));
+
+  if (visible_only)
+    flatten (vc->table, visible_variable_in_context, vlist, 0);
+  else
+    flatten (vc->table, variable_in_context, vlist, 0);
+
+  ret = vlist->list;
+  free (vlist);
+  if (ret)
+    sort_variables (ret);
+  return ret;
+}
+
+#if defined (ARRAY_VARS)
+/* Return non-zero if the variable VAR is visible and an array. */
+static int
+visible_array_vars (var)
+     SHELL_VAR *var;
+{
+  return (invisible_p (var) == 0 && (array_p (var) || assoc_p (var)));
+}
+
+SHELL_VAR **
+all_array_variables ()
+{
+  return (vapply (visible_array_vars));
+}
+#endif /* ARRAY_VARS */
+
+char **
+all_variables_matching_prefix (prefix)
+     const char *prefix;
+{
+  SHELL_VAR **varlist;
+  char **rlist;
+  int vind, rind, plen;
+
+  plen = STRLEN (prefix);
+  varlist = all_visible_variables ();
+  for (vind = 0; varlist && varlist[vind]; vind++)
+    ;
+  if (varlist == 0 || vind == 0)
+    return ((char **)NULL);
+  rlist = strvec_create (vind + 1);
+  for (vind = rind = 0; varlist[vind]; vind++)
+    {
+      if (plen == 0 || STREQN (prefix, varlist[vind]->name, plen))
+	rlist[rind++] = savestring (varlist[vind]->name);
+    }
+  rlist[rind] = (char *)0;
+  free (varlist);
+
+  return rlist;
+}
+
+/* **************************************************************** */
+/*								    */
+/*		 Managing temporary variable scopes		    */
+/*								    */
+/* **************************************************************** */
+
+/* Make variable NAME have VALUE in the temporary environment. */
+static SHELL_VAR *
+bind_tempenv_variable (name, value)
+     const char *name;
+     char *value;
+{
+  SHELL_VAR *var;
+
+  var = temporary_env ? hash_lookup (name, temporary_env) : (SHELL_VAR *)NULL;
+
+  if (var)
+    {
+      FREE (value_cell (var));
+      var_setvalue (var, savestring (value));
+      INVALIDATE_EXPORTSTR (var);
+    }
+
+  return (var);
+}
+
+/* Find a variable in the temporary environment that is named NAME.
+   Return the SHELL_VAR *, or NULL if not found. */
+SHELL_VAR *
+find_tempenv_variable (name)
+     const char *name;
+{
+  return (temporary_env ? hash_lookup (name, temporary_env) : (SHELL_VAR *)NULL);
+}
+
+char **tempvar_list;
+int tvlist_ind;
+
+/* Take a variable from an assignment statement preceding a posix special
+   builtin (including `return') and create a global variable from it. This
+   is called from merge_temporary_env, which is only called when in posix
+   mode. */
+static void
+push_posix_temp_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var, *v;
+  HASH_TABLE *binding_table;
+
+  var = (SHELL_VAR *)data;
+
+  /* Just like do_assignment_internal(). This makes assignments preceding
+     special builtins act like standalone assignment statements when in
+     posix mode, satisfying the posix requirement that this affect the
+     "current execution environment." */
+  v = bind_variable (var->name, value_cell (var), ASS_FORCE|ASS_NOLONGJMP);
+
+  /* XXX - do we need to worry about array variables here? */
+
+  /* If this modifies an existing local variable, v->context will be non-zero.
+     If it comes back with v->context == 0, we bound at the global context.
+     Set binding_table appropriately. It doesn't matter whether it's correct
+     if the variable is local, only that it's not global_variables->table */
+  binding_table = v->context ? shell_variables->table : global_variables->table;
+
+  /* global variables are no longer temporary and don't need propagating. */
+  if (v->context == 0)
+    var->attributes &= ~(att_tempvar|att_propagate);
+
+  if (v)
+    {
+      v->attributes |= var->attributes;		/* preserve tempvar attribute if appropriate */
+      /* If we don't bind a local variable, propagate the value. If we bind a
+	 local variable (the "current execution environment"), keep it as local
+	 and don't propagate it to the calling environment. */
+      if (v->context > 0 && local_p (v) == 0)
+	v->attributes |= att_propagate;
+      else
+	v->attributes &= ~att_propagate;
+    }
+
+  if (find_special_var (var->name) >= 0)
+    tempvar_list[tvlist_ind++] = savestring (var->name);
+
+  dispose_variable (var);
+}
+
+/* Push the variable described by (SHELL_VAR *)DATA down to the next
+   variable context from the temporary environment. This can be called
+   from one context:
+      1. propagate_temp_var: which is called to propagate variables in
+	 assignments like `var=value declare -x var' to the surrounding
+	 scope.
+
+  In this case, the variable should have the att_propagate flag set and
+  we can create variables in the current scope.
+*/
+static void
+push_temp_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var, *v;
+  HASH_TABLE *binding_table;
+
+  var = (SHELL_VAR *)data;
+
+  binding_table = shell_variables->table;
+  if (binding_table == 0)
+    {
+      if (shell_variables == global_variables)
+	/* shouldn't happen */
+	binding_table = shell_variables->table = global_variables->table = hash_create (VARIABLES_HASH_BUCKETS);
+      else
+	binding_table = shell_variables->table = hash_create (TEMPENV_HASH_BUCKETS);
+    }
+
+  v = bind_variable_internal (var->name, value_cell (var), binding_table, 0, ASS_FORCE|ASS_NOLONGJMP);
+
+  /* XXX - should we set the context here?  It shouldn't matter because of how
+     assign_in_env works, but we do it anyway. */
+  if (v)
+    v->context = shell_variables->scope;
+
+  if (binding_table == global_variables->table)		/* XXX */
+    var->attributes &= ~(att_tempvar|att_propagate);
+  else
+    {
+      var->attributes |= att_propagate;			/* XXX - propagate more than once? */
+      if  (binding_table == shell_variables->table)
+	shell_variables->flags |= VC_HASTMPVAR;
+    }
+  if (v)
+    v->attributes |= var->attributes;
+
+  if (find_special_var (var->name) >= 0)
+    tempvar_list[tvlist_ind++] = savestring (var->name);
+
+  dispose_variable (var);
+}
+
+/* Take a variable described by DATA and push it to the surrounding scope if
+   the PROPAGATE attribute is set. That gets set by push_temp_var if we are
+   taking a variable like `var=value declare -x var' and propagating it to
+   the enclosing scope. */
+static void
+propagate_temp_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var;
+
+  var = (SHELL_VAR *)data;
+  if (tempvar_p (var) && (var->attributes & att_propagate))
+    push_temp_var (data);
+  else
+    {
+      if (find_special_var (var->name) >= 0)
+	tempvar_list[tvlist_ind++] = savestring (var->name);
+      dispose_variable (var);
+    }
+}
+
+/* Free the storage used in the hash table for temporary
+   environment variables.  PUSHF is a function to be called
+   to free each hash table entry.  It takes care of pushing variables
+   to previous scopes if appropriate.  PUSHF stores names of variables
+   that require special handling (e.g., IFS) on tempvar_list, so this
+   function can call stupidly_hack_special_variables on all the
+   variables in the list when the temporary hash table is destroyed. */
+static void
+dispose_temporary_env (pushf)
+     sh_free_func_t *pushf;
+{
+  int i;
+  HASH_TABLE *disposer;
+
+  tempvar_list = strvec_create (HASH_ENTRIES (temporary_env) + 1);
+  tempvar_list[tvlist_ind = 0] = 0;
+
+  disposer = temporary_env;
+  temporary_env = (HASH_TABLE *)NULL;
+
+  hash_flush (disposer, pushf);
+  hash_dispose (disposer);
+
+  tempvar_list[tvlist_ind] = 0;
+
+  array_needs_making = 1;
+
+  for (i = 0; i < tvlist_ind; i++)
+    stupidly_hack_special_variables (tempvar_list[i]);
+
+  strvec_dispose (tempvar_list);
+  tempvar_list = 0;
+  tvlist_ind = 0;
+}
+
+void
+dispose_used_env_vars ()
+{
+  if (temporary_env)
+    {
+      dispose_temporary_env (propagate_temp_var);
+      maybe_make_export_env ();
+    }
+}
+
+/* Take all of the shell variables in the temporary environment HASH_TABLE
+   and make shell variables from them at the current variable context.
+   Right now, this is only called in Posix mode to implement the historical
+   accident of creating global variables from assignment statements preceding
+   special builtins, but we check in case this acquires another caller later. */
+void
+merge_temporary_env ()
+{
+  if (temporary_env)
+    dispose_temporary_env (posixly_correct ? push_posix_temp_var : push_temp_var);
+}
+
+/* Temporary function to use if we want to separate function and special
+   builtin behavior. */
+void
+merge_function_temporary_env ()
+{
+  if (temporary_env)
+    dispose_temporary_env (push_temp_var);
+}
+
+void
+flush_temporary_env ()
+{
+  if (temporary_env)
+    {
+      hash_flush (temporary_env, free_variable_hash_data);
+      hash_dispose (temporary_env);
+      temporary_env = (HASH_TABLE *)NULL;
+    }
+}
+
+/* **************************************************************** */
+/*								    */
+/*	     Creating and manipulating the environment		    */
+/*								    */
+/* **************************************************************** */
+
+static inline char *
+mk_env_string (name, value, attributes)
+     const char *name, *value;
+     int attributes;
+{
+  size_t name_len, value_len;
+  char	*p, *q, *t;
+  int isfunc, isarray;
+
+  name_len = strlen (name);
+  value_len = STRLEN (value);
+
+  isfunc = attributes & att_function;
+#if defined (ARRAY_VARS) && defined (ARRAY_EXPORT)
+  isarray = attributes & (att_array|att_assoc);
+#endif
+
+  /* If we are exporting a shell function, construct the encoded function
+     name. */
+  if (isfunc && value)
+    {
+      p = (char *)xmalloc (BASHFUNC_PREFLEN + name_len + BASHFUNC_SUFFLEN + value_len + 2);
+      q = p;
+      memcpy (q, BASHFUNC_PREFIX, BASHFUNC_PREFLEN);
+      q += BASHFUNC_PREFLEN;
+      memcpy (q, name, name_len);
+      q += name_len;
+      memcpy (q, BASHFUNC_SUFFIX, BASHFUNC_SUFFLEN);
+      q += BASHFUNC_SUFFLEN;
+    }
+#if defined (ARRAY_VARS) && defined (ARRAY_EXPORT)
+  else if (isarray && value)
+    {
+      if (attributes & att_assoc)
+	p = (char *)xmalloc (BASHASSOC_PREFLEN + name_len + BASHASSOC_SUFFLEN + value_len + 2);
+      else
+	p = (char *)xmalloc (BASHARRAY_PREFLEN + name_len + BASHARRAY_SUFFLEN + value_len + 2);
+      q = p;
+      if (attributes & att_assoc)
+	{
+	  memcpy (q, BASHASSOC_PREFIX, BASHASSOC_PREFLEN);
+	  q += BASHASSOC_PREFLEN;
+	}
+      else
+	{
+	  memcpy (q, BASHARRAY_PREFIX, BASHARRAY_PREFLEN);
+	  q += BASHARRAY_PREFLEN;
+	}
+      memcpy (q, name, name_len);
+      q += name_len;
+      /* These are actually the same currently */
+      if (attributes & att_assoc)
+        {
+	  memcpy (q, BASHASSOC_SUFFIX, BASHASSOC_SUFFLEN);
+	  q += BASHARRAY_SUFFLEN;
+        }
+      else
+        {
+	  memcpy (q, BASHARRAY_SUFFIX, BASHARRAY_SUFFLEN);
+	  q += BASHARRAY_SUFFLEN;
+        }
+    }
+#endif  
+  else
+    {
+      p = (char *)xmalloc (2 + name_len + value_len);
+      memcpy (p, name, name_len);
+      q = p + name_len;
+    }
+
+  q[0] = '=';
+  if (value && *value)
+    {
+      if (isfunc)
+	{
+	  t = dequote_escapes (value);
+	  value_len = STRLEN (t);
+	  memcpy (q + 1, t, value_len + 1);
+	  free (t);
+	}
+      else
+	memcpy (q + 1, value, value_len + 1);
+    }
+  else
+    q[1] = '\0';
+
+  return (p);
+}
+
+#ifdef DEBUG
+/* Debugging */
+static int
+valid_exportstr (v)
+     SHELL_VAR *v;
+{
+  char *s;
+
+  s = v->exportstr;
+  if (s == 0)
+    {
+      internal_error (_("%s has null exportstr"), v->name);
+      return (0);
+    }
+  if (legal_variable_starter ((unsigned char)*s) == 0)
+    {
+      internal_error (_("invalid character %d in exportstr for %s"), *s, v->name);
+      return (0);
+    }
+  for (s = v->exportstr + 1; s && *s; s++)
+    {
+      if (*s == '=')
+	break;
+      if (legal_variable_char ((unsigned char)*s) == 0)
+	{
+	  internal_error (_("invalid character %d in exportstr for %s"), *s, v->name);
+	  return (0);
+	}
+    }
+  if (*s != '=')
+    {
+      internal_error (_("no `=' in exportstr for %s"), v->name);
+      return (0);
+    }
+  return (1);
+}
+#endif
+
+#if defined (ARRAY_VARS)
+#  define USE_EXPORTSTR (value == var->exportstr && array_p (var) == 0 && assoc_p (var) == 0)
+#else
+#  define USE_EXPORTSTR (value == var->exportstr)
+#endif
+
+static char **
+make_env_array_from_var_list (vars)
+     SHELL_VAR **vars;
+{
+  register int i, list_index;
+  register SHELL_VAR *var;
+  char **list, *value;
+
+  list = strvec_create ((1 + strvec_len ((char **)vars)));
+
+  for (i = 0, list_index = 0; var = vars[i]; i++)
+    {
+#if defined (__CYGWIN__)
+      /* We don't use the exportstr stuff on Cygwin at all. */
+      INVALIDATE_EXPORTSTR (var);
+#endif
+
+      /* If the value is generated dynamically, generate it here. */
+      if (regen_p (var) && var->dynamic_value)
+	{
+	  var = (*(var->dynamic_value)) (var);
+	  INVALIDATE_EXPORTSTR (var);
+	}
+
+      if (var->exportstr)
+	value = var->exportstr;
+      else if (function_p (var))
+	value = named_function_string ((char *)NULL, function_cell (var), 0);
+#if defined (ARRAY_VARS)
+      else if (array_p (var))
+#  if ARRAY_EXPORT
+	value = array_to_assign (array_cell (var), 0);
+#  else
+	continue;	/* XXX array vars cannot yet be exported */
+#  endif /* ARRAY_EXPORT */
+      else if (assoc_p (var))
+#  if ARRAY_EXPORT
+	value = assoc_to_assign (assoc_cell (var), 0);
+#  else
+	continue;	/* XXX associative array vars cannot yet be exported */
+#  endif /* ARRAY_EXPORT */
+#endif
+      else
+	value = value_cell (var);
+
+      if (value)
+	{
+	  /* Gee, I'd like to get away with not using savestring() if we're
+	     using the cached exportstr... */
+	  list[list_index] = USE_EXPORTSTR ? savestring (value)
+					   : mk_env_string (var->name, value, var->attributes);
+
+	  if (USE_EXPORTSTR == 0)
+	    SAVE_EXPORTSTR (var, list[list_index]);
+
+	  list_index++;
+#undef USE_EXPORTSTR
+
+#if defined (ARRAY_VARS) && defined (ARRAY_EXPORT)
+	  if (array_p (var) || assoc_p (var))
+	    free (value);
+#endif
+	}
+    }
+
+  list[list_index] = (char *)NULL;
+  return (list);
+}
+
+/* Make an array of assignment statements from the hash table
+   HASHED_VARS which contains SHELL_VARs.  Only visible, exported
+   variables are eligible. */
+static char **
+make_var_export_array (vcxt)
+     VAR_CONTEXT *vcxt;
+{
+  char **list;
+  SHELL_VAR **vars;
+
+#if 0
+  vars = map_over (visible_and_exported, vcxt);
+#else
+  vars = map_over (export_environment_candidate, vcxt);
+#endif
+
+  if (vars == 0)
+    return (char **)NULL;
+
+  list = make_env_array_from_var_list (vars);
+
+  free (vars);
+  return (list);
+}
+
+static char **
+make_func_export_array ()
+{
+  char **list;
+  SHELL_VAR **vars;
+
+  vars = map_over_funcs (visible_and_exported);
+  if (vars == 0)
+    return (char **)NULL;
+
+  list = make_env_array_from_var_list (vars);
+
+  free (vars);
+  return (list);
+}
+
+/* Add ENVSTR to the end of the exported environment, EXPORT_ENV. */
+#define add_to_export_env(envstr,do_alloc) \
+do \
+  { \
+    if (export_env_index >= (export_env_size - 1)) \
+      { \
+	export_env_size += 16; \
+	export_env = strvec_resize (export_env, export_env_size); \
+	environ = export_env; \
+      } \
+    export_env[export_env_index++] = (do_alloc) ? savestring (envstr) : envstr; \
+    export_env[export_env_index] = (char *)NULL; \
+  } while (0)
+
+/* Add ASSIGN to EXPORT_ENV, or supersede a previous assignment in the
+   array with the same left-hand side.  Return the new EXPORT_ENV. */
+char **
+add_or_supercede_exported_var (assign, do_alloc)
+     char *assign;
+     int do_alloc;
+{
+  register int i;
+  int equal_offset;
+
+  equal_offset = assignment (assign, 0);
+  if (equal_offset == 0)
+    return (export_env);
+
+  /* If this is a function, then only supersede the function definition.
+     We do this by including the `=() {' in the comparison, like
+     initialize_shell_variables does. */
+  if (assign[equal_offset + 1] == '(' &&
+     strncmp (assign + equal_offset + 2, ") {", 3) == 0)		/* } */
+    equal_offset += 4;
+
+  for (i = 0; i < export_env_index; i++)
+    {
+      if (STREQN (assign, export_env[i], equal_offset + 1))
+	{
+	  free (export_env[i]);
+	  export_env[i] = do_alloc ? savestring (assign) : assign;
+	  return (export_env);
+	}
+    }
+  add_to_export_env (assign, do_alloc);
+  return (export_env);
+}
+
+static void
+add_temp_array_to_env (temp_array, do_alloc, do_supercede)
+     char **temp_array;
+     int do_alloc, do_supercede;
+{
+  register int i;
+
+  if (temp_array == 0)
+    return;
+
+  for (i = 0; temp_array[i]; i++)
+    {
+      if (do_supercede)
+	export_env = add_or_supercede_exported_var (temp_array[i], do_alloc);
+      else
+	add_to_export_env (temp_array[i], do_alloc);
+    }
+
+  free (temp_array);
+}
+
+/* Make the environment array for the command about to be executed, if the
+   array needs making.  Otherwise, do nothing.  If a shell action could
+   change the array that commands receive for their environment, then the
+   code should `array_needs_making++'.
+
+   The order to add to the array is:
+   	temporary_env
+   	list of var contexts whose head is shell_variables
+  	shell_functions
+
+  This is the shell variable lookup order.  We add only new variable
+  names at each step, which allows local variables and variables in
+  the temporary environments to shadow variables in the global (or
+  any previous) scope.
+*/
+
+static int
+n_shell_variables ()
+{
+  VAR_CONTEXT *vc;
+  int n;
+
+  for (n = 0, vc = shell_variables; vc; vc = vc->down)
+    n += HASH_ENTRIES (vc->table);
+  return n;
+}
+
+int
+chkexport (name)
+     char *name;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v && exported_p (v))
+    {
+      array_needs_making = 1;
+      maybe_make_export_env ();
+      return 1;
+    }
+  return 0;
+}
+
+void
+maybe_make_export_env ()
+{
+  register char **temp_array;
+  int new_size;
+  VAR_CONTEXT *tcxt, *icxt;
+
+  if (array_needs_making)
+    {
+      if (export_env)
+	strvec_flush (export_env);
+
+      /* Make a guess based on how many shell variables and functions we
+	 have.  Since there will always be array variables, and array
+	 variables are not (yet) exported, this will always be big enough
+	 for the exported variables and functions. */
+      new_size = n_shell_variables () + HASH_ENTRIES (shell_functions) + 1 +
+		 HASH_ENTRIES (temporary_env) + HASH_ENTRIES (invalid_env);
+      if (new_size > export_env_size)
+	{
+	  export_env_size = new_size;
+	  export_env = strvec_resize (export_env, export_env_size);
+	  environ = export_env;
+	}
+      export_env[export_env_index = 0] = (char *)NULL;
+
+      /* Make a dummy variable context from the temporary_env, stick it on
+	 the front of shell_variables, call make_var_export_array on the
+	 whole thing to flatten it, and convert the list of SHELL_VAR *s
+	 to the form needed by the environment. */
+      if (temporary_env)
+	{
+	  tcxt = new_var_context ((char *)NULL, 0);
+	  tcxt->table = temporary_env;
+	  tcxt->down = shell_variables;
+	}
+      else
+	tcxt = shell_variables;
+
+      if (invalid_env)
+	{
+	  icxt = new_var_context ((char *)NULL, 0);
+	  icxt->table = invalid_env;
+	  icxt->down = tcxt;
+	}
+      else
+	icxt = tcxt;
+      
+      temp_array = make_var_export_array (icxt);
+      if (temp_array)
+	add_temp_array_to_env (temp_array, 0, 0);
+
+      if (icxt != tcxt)
+	free (icxt);
+
+      if (tcxt != shell_variables)
+	free (tcxt);
+
+#if defined (RESTRICTED_SHELL)
+      /* Restricted shells may not export shell functions. */
+      temp_array = restricted ? (char **)0 : make_func_export_array ();
+#else
+      temp_array = make_func_export_array ();
+#endif
+      if (temp_array)
+	add_temp_array_to_env (temp_array, 0, 0);
+
+      array_needs_making = 0;
+    }
+}
+
+/* This is an efficiency hack.  PWD and OLDPWD are auto-exported, so
+   we will need to remake the exported environment every time we
+   change directories.  `_' is always put into the environment for
+   every external command, so without special treatment it will always
+   cause the environment to be remade.
+
+   If there is no other reason to make the exported environment, we can
+   just update the variables in place and mark the exported environment
+   as no longer needing a remake. */
+void
+update_export_env_inplace (env_prefix, preflen, value)
+     char *env_prefix;
+     int preflen;
+     char *value;
+{
+  char *evar;
+
+  evar = (char *)xmalloc (STRLEN (value) + preflen + 1);
+  strcpy (evar, env_prefix);
+  if (value)
+    strcpy (evar + preflen, value);
+  export_env = add_or_supercede_exported_var (evar, 0);
+}
+
+/* We always put _ in the environment as the name of this command. */
+void
+put_command_name_into_env (command_name)
+     char *command_name;
+{
+  update_export_env_inplace ("_=", 2, command_name);
+}
+
+/* **************************************************************** */
+/*								    */
+/*		      Managing variable contexts		    */
+/*								    */
+/* **************************************************************** */
+
+/* Allocate and return a new variable context with NAME and FLAGS.
+   NAME can be NULL. */
+
+VAR_CONTEXT *
+new_var_context (name, flags)
+     char *name;
+     int flags;
+{
+  VAR_CONTEXT *vc;
+
+  vc = (VAR_CONTEXT *)xmalloc (sizeof (VAR_CONTEXT));
+  vc->name = name ? savestring (name) : (char *)NULL;
+  vc->scope = variable_context;
+  vc->flags = flags;
+
+  vc->up = vc->down = (VAR_CONTEXT *)NULL;
+  vc->table = (HASH_TABLE *)NULL;
+
+  return vc;
+}
+
+/* Free a variable context and its data, including the hash table.  Dispose
+   all of the variables. */
+void
+dispose_var_context (vc)
+     VAR_CONTEXT *vc;
+{
+  FREE (vc->name);
+
+  if (vc->table)
+    {
+      delete_all_variables (vc->table);
+      hash_dispose (vc->table);
+    }
+
+  free (vc);
+}
+
+/* Set VAR's scope level to the current variable context. */
+static int
+set_context (var)
+     SHELL_VAR *var;
+{
+  return (var->context = variable_context);
+}
+
+/* Make a new variable context with NAME and FLAGS and a HASH_TABLE of
+   temporary variables, and push it onto shell_variables.  This is
+   for shell functions. */
+VAR_CONTEXT *
+push_var_context (name, flags, tempvars)
+     char *name;
+     int flags;
+     HASH_TABLE *tempvars;
+{
+  VAR_CONTEXT *vc;
+  int posix_func_behavior;
+
+  /* As of IEEE Std 1003.1-2017, assignment statements preceding shell
+     functions no longer behave like assignment statements preceding
+     special builtins, and do not persist in the current shell environment.
+     This is austin group interp #654, though nobody implements it yet. */
+  posix_func_behavior = 0;
+
+  vc = new_var_context (name, flags);
+  /* Posix interp 1009, temporary assignments preceding function calls modify
+     the current environment *before* the command is executed. */
+  if (posix_func_behavior && (flags & VC_FUNCENV) && tempvars == temporary_env)
+    merge_temporary_env ();
+  else if (tempvars)
+    {
+      vc->table = tempvars;
+      /* Have to do this because the temp environment was created before
+	 variable_context was incremented. */
+      /* XXX - only need to do it if flags&VC_FUNCENV */
+      flatten (tempvars, set_context, (VARLIST *)NULL, 0);
+      vc->flags |= VC_HASTMPVAR;
+    }
+  vc->down = shell_variables;
+  shell_variables->up = vc;
+
+  return (shell_variables = vc);
+}
+
+/* This can be called from one of two code paths:
+	1. pop_scope, which implements the posix rules for propagating variable
+	   assignments preceding special builtins to the surrounding scope
+	   (push_builtin_var -- isbltin == 1);
+	2. pop_var_context, which is called from pop_context and implements the
+	   posix rules for propagating variable assignments preceding function
+	   calls to the surrounding scope (push_func_var -- isbltin == 0)
+
+  It takes variables out of a temporary environment hash table. We take the
+  variable in data.
+*/
+
+static inline void
+push_posix_tempvar_internal (var, isbltin)
+     SHELL_VAR *var;
+     int isbltin;
+{
+  SHELL_VAR *v;
+  int posix_var_behavior;
+
+  /* As of IEEE Std 1003.1-2017, assignment statements preceding shell
+     functions no longer behave like assignment statements preceding
+     special builtins, and do not persist in the current shell environment.
+     This is austin group interp #654, though nobody implements it yet. */
+  posix_var_behavior = posixly_correct && isbltin;
+  v = 0;
+
+  if (local_p (var) && STREQ (var->name, "-"))
+    {
+      set_current_options (value_cell (var));
+      set_shellopts ();
+    }
+  /* This takes variable assignments preceding special builtins that can execute
+     multiple commands (source, eval, etc.) and performs the equivalent of
+     an assignment statement to modify the closest enclosing variable (the
+     posix "current execution environment"). This makes the behavior the same
+     as push_posix_temp_var; but the circumstances of calling are slightly
+     different. */
+  else if (tempvar_p (var) && posix_var_behavior)
+    {
+      /* similar to push_posix_temp_var */
+      v = bind_variable (var->name, value_cell (var), ASS_FORCE|ASS_NOLONGJMP);
+      if (v)
+	{
+	  v->attributes |= var->attributes;
+	  if (v->context == 0)
+	    v->attributes &= ~(att_tempvar|att_propagate);
+	  /* XXX - set att_propagate here if v->context > 0? */
+	}
+    }
+  else if (tempvar_p (var) && propagate_p (var))
+    {
+      /* Make sure we have a hash table to store the variable in while it is
+	 being propagated down to the global variables table.  Create one if
+	 we have to */
+      if ((vc_isfuncenv (shell_variables) || vc_istempenv (shell_variables)) && shell_variables->table == 0)
+	shell_variables->table = hash_create (VARIABLES_HASH_BUCKETS);
+      v = bind_variable_internal (var->name, value_cell (var), shell_variables->table, 0, 0);
+      /* XXX - should we set v->context here? */
+      if (v)
+	v->context = shell_variables->scope;
+      if (shell_variables == global_variables)
+	var->attributes &= ~(att_tempvar|att_propagate);
+      else
+	shell_variables->flags |= VC_HASTMPVAR;
+      if (v)
+	v->attributes |= var->attributes;
+    }
+  else
+    stupidly_hack_special_variables (var->name);	/* XXX */
+
+#if defined (ARRAY_VARS)
+  if (v && (array_p (var) || assoc_p (var)))
+    {
+      FREE (value_cell (v));
+      if (array_p (var))
+	var_setarray (v, array_copy (array_cell (var)));
+      else
+	var_setassoc (v, assoc_copy (assoc_cell (var)));
+    }
+#endif	  
+
+  dispose_variable (var);
+}
+
+static void
+push_func_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var;
+
+  var = (SHELL_VAR *)data;
+  push_posix_tempvar_internal (var, 0);
+}
+
+static void
+push_builtin_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var;
+
+  var = (SHELL_VAR *)data;
+  push_posix_tempvar_internal (var, 1);
+}
+
+/* Pop the top context off of VCXT and dispose of it, returning the rest of
+   the stack. */
+void
+pop_var_context ()
+{
+  VAR_CONTEXT *ret, *vcxt;
+
+  vcxt = shell_variables;
+  if (vc_isfuncenv (vcxt) == 0)
+    {
+      internal_error (_("pop_var_context: head of shell_variables not a function context"));
+      return;
+    }
+
+  if (ret = vcxt->down)
+    {
+      ret->up = (VAR_CONTEXT *)NULL;
+      shell_variables = ret;
+      if (vcxt->table)
+	hash_flush (vcxt->table, push_func_var);
+      dispose_var_context (vcxt);
+    }
+  else
+    internal_error (_("pop_var_context: no global_variables context"));
+}
+
+static void
+delete_local_contexts (vcxt)
+     VAR_CONTEXT *vcxt;
+{
+  VAR_CONTEXT *v, *t;
+
+  for (v = vcxt; v != global_variables; v = t)
+    {
+      t = v->down;
+      dispose_var_context (v);
+    }
+}
+
+/* Delete the HASH_TABLEs for all variable contexts beginning at VCXT, and
+   all of the VAR_CONTEXTs except GLOBAL_VARIABLES. */
+void
+delete_all_contexts (vcxt)
+     VAR_CONTEXT *vcxt;
+{
+  delete_local_contexts (vcxt);
+  delete_all_variables (global_variables->table);
+  shell_variables = global_variables;
+}
+
+/* Reset the context so we are not executing in a shell function. Only call
+   this if you are getting ready to exit the shell. */
+void
+reset_local_contexts ()
+{
+  delete_local_contexts (shell_variables);
+  shell_variables = global_variables;
+  variable_context = 0;
+}
+
+/* **************************************************************** */
+/*								    */
+/*	   Pushing and Popping temporary variable scopes	    */
+/*								    */
+/* **************************************************************** */
+
+VAR_CONTEXT *
+push_scope (flags, tmpvars)
+     int flags;
+     HASH_TABLE *tmpvars;
+{
+  return (push_var_context ((char *)NULL, flags, tmpvars));
+}
+
+static void
+push_exported_var (data)
+     PTR_T data;
+{
+  SHELL_VAR *var, *v;
+
+  var = (SHELL_VAR *)data;
+
+  /* If a temp var had its export attribute set, or it's marked to be
+     propagated, bind it in the previous scope before disposing it. */
+  /* XXX - This isn't exactly right, because all tempenv variables have the
+    export attribute set. */
+  if (tempvar_p (var) && exported_p (var) && (var->attributes & att_propagate))
+    {
+      var->attributes &= ~att_tempvar;		/* XXX */
+      v = bind_variable_internal (var->name, value_cell (var), shell_variables->table, 0, 0);
+      if (shell_variables == global_variables)
+	var->attributes &= ~att_propagate;
+      if (v)
+	{
+	  v->attributes |= var->attributes;
+	  v->context = shell_variables->scope;
+	}
+    }
+  else
+    stupidly_hack_special_variables (var->name);	/* XXX */
+
+  dispose_variable (var);
+}
+
+/* This is called to propagate variables in the temporary environment of a
+   special builtin (if IS_SPECIAL != 0) or exported variables that are the
+   result of a builtin like `source' or `command' that can operate on the
+   variables in its temporary environment. In the first case, we call
+   push_builtin_var, which does the right thing. */
+void
+pop_scope (is_special)
+     int is_special;
+{
+  VAR_CONTEXT *vcxt, *ret;
+  int is_bltinenv;
+
+  vcxt = shell_variables;
+  if (vc_istempscope (vcxt) == 0)
+    {
+      internal_error (_("pop_scope: head of shell_variables not a temporary environment scope"));
+      return;
+    }
+  is_bltinenv = vc_isbltnenv (vcxt);	/* XXX - for later */
+
+  ret = vcxt->down;
+  if (ret)
+    ret->up = (VAR_CONTEXT *)NULL;
+
+  shell_variables = ret;
+
+  /* Now we can take care of merging variables in VCXT into set of scopes
+     whose head is RET (shell_variables). */
+  FREE (vcxt->name);
+  if (vcxt->table)
+    {
+      if (is_special)
+	hash_flush (vcxt->table, push_builtin_var);
+      else
+	hash_flush (vcxt->table, push_exported_var);
+      hash_dispose (vcxt->table);
+    }
+  free (vcxt);
+
+  sv_ifs ("IFS");	/* XXX here for now */
+}
+
+/* **************************************************************** */
+/*								    */
+/*		 Pushing and Popping function contexts		    */
+/*								    */
+/* **************************************************************** */
+
+struct saved_dollar_vars {
+  char **first_ten;
+  WORD_LIST *rest;
+  int count;
+};
+
+static struct saved_dollar_vars *dollar_arg_stack = (struct saved_dollar_vars *)NULL;
+static int dollar_arg_stack_slots;
+static int dollar_arg_stack_index;
+
+/* Functions to manipulate dollar_vars array. Need to keep these in sync with
+   whatever remember_args() does. */
+static char **
+save_dollar_vars ()
+{
+  char **ret;
+  int i;
+
+  ret = strvec_create (10);
+  for (i = 1; i < 10; i++)
+    {
+      ret[i] = dollar_vars[i];
+      dollar_vars[i] = (char *)NULL;
+    }
+  return ret;
+}
+
+static void
+restore_dollar_vars (args)
+     char **args;
+{
+  int i;
+
+  for (i = 1; i < 10; i++)
+    dollar_vars[i] = args[i];
+}
+
+static void
+free_dollar_vars ()
+{
+  int i;
+
+  for (i = 1; i < 10; i++)
+    {
+      FREE (dollar_vars[i]);
+      dollar_vars[i] = (char *)NULL;
+    }
+}
+
+static void
+free_saved_dollar_vars (args)
+     char **args;
+{
+  int i;
+
+  for (i = 1; i < 10; i++)
+    FREE (args[i]);
+}
+
+/* Do what remember_args (xxx, 1) would have done. */
+void
+clear_dollar_vars ()
+{
+  free_dollar_vars ();
+  dispose_words (rest_of_args);
+
+  rest_of_args = (WORD_LIST *)NULL;
+  posparam_count = 0;
+}
+
+/* XXX - should always be followed by remember_args () */
+void
+push_context (name, is_subshell, tempvars)
+     char *name;	/* function name */
+     int is_subshell;
+     HASH_TABLE *tempvars;
+{
+  if (is_subshell == 0)
+    push_dollar_vars ();
+  variable_context++;
+  push_var_context (name, VC_FUNCENV, tempvars);
+}
+
+/* Only called when subshell == 0, so we don't need to check, and can
+   unconditionally pop the dollar vars off the stack. */
+void
+pop_context ()
+{
+  pop_dollar_vars ();
+  variable_context--;
+  pop_var_context ();
+
+  sv_ifs ("IFS");		/* XXX here for now */
+}
+
+/* Save the existing positional parameters on a stack. */
+void
+push_dollar_vars ()
+{
+  if (dollar_arg_stack_index + 2 > dollar_arg_stack_slots)
+    {
+      dollar_arg_stack = (struct saved_dollar_vars *)
+	xrealloc (dollar_arg_stack, (dollar_arg_stack_slots += 10)
+		  * sizeof (struct saved_dollar_vars));
+    }
+
+  dollar_arg_stack[dollar_arg_stack_index].count = posparam_count;
+  dollar_arg_stack[dollar_arg_stack_index].first_ten = save_dollar_vars ();
+  dollar_arg_stack[dollar_arg_stack_index++].rest = rest_of_args;
+  rest_of_args = (WORD_LIST *)NULL;
+  posparam_count = 0;
+  
+  dollar_arg_stack[dollar_arg_stack_index].first_ten = (char **)NULL;
+  dollar_arg_stack[dollar_arg_stack_index].rest = (WORD_LIST *)NULL;  
+}
+
+/* Restore the positional parameters from our stack. */
+void
+pop_dollar_vars ()
+{
+  if (dollar_arg_stack == 0 || dollar_arg_stack_index == 0)
+    return;
+
+  /* Wipe out current values */
+  clear_dollar_vars ();
+
+  rest_of_args = dollar_arg_stack[--dollar_arg_stack_index].rest;
+  restore_dollar_vars (dollar_arg_stack[dollar_arg_stack_index].first_ten);
+  free (dollar_arg_stack[dollar_arg_stack_index].first_ten);
+  posparam_count = dollar_arg_stack[dollar_arg_stack_index].count;
+
+  dollar_arg_stack[dollar_arg_stack_index].first_ten = (char **)NULL;
+  dollar_arg_stack[dollar_arg_stack_index].rest = (WORD_LIST *)NULL;
+  dollar_arg_stack[dollar_arg_stack_index].count = 0;
+
+  set_dollar_vars_unchanged ();
+  invalidate_cached_quoted_dollar_at ();
+}
+
+void
+dispose_saved_dollar_vars ()
+{
+  if (dollar_arg_stack == 0 || dollar_arg_stack_index == 0)
+    return;
+
+  dispose_words (dollar_arg_stack[--dollar_arg_stack_index].rest);    
+  free_saved_dollar_vars (dollar_arg_stack[dollar_arg_stack_index].first_ten);	
+  free (dollar_arg_stack[dollar_arg_stack_index].first_ten);
+
+  dollar_arg_stack[dollar_arg_stack_index].first_ten = (char **)NULL;  
+  dollar_arg_stack[dollar_arg_stack_index].rest = (WORD_LIST *)NULL;
+  dollar_arg_stack[dollar_arg_stack_index].count = 0;
+}
+
+/* Initialize BASH_ARGV and BASH_ARGC after turning on extdebug after the
+   shell is initialized */
+void
+init_bash_argv ()
+{
+  if (bash_argv_initialized == 0)
+    {
+      save_bash_argv ();
+      bash_argv_initialized = 1;
+    }
+}
+
+void
+save_bash_argv ()
+{
+  WORD_LIST *list;
+
+  list = list_rest_of_args ();
+  push_args (list);
+  dispose_words (list);
+}
+
+/* Manipulate the special BASH_ARGV and BASH_ARGC variables. */
+
+void
+push_args (list)
+     WORD_LIST *list;
+{
+#if defined (ARRAY_VARS) && defined (DEBUGGER)
+  SHELL_VAR *bash_argv_v, *bash_argc_v;
+  ARRAY *bash_argv_a, *bash_argc_a;
+  WORD_LIST *l;
+  arrayind_t i;
+  char *t;
+
+  GET_ARRAY_FROM_VAR ("BASH_ARGV", bash_argv_v, bash_argv_a);
+  GET_ARRAY_FROM_VAR ("BASH_ARGC", bash_argc_v, bash_argc_a);
+
+  for (l = list, i = 0; l; l = l->next, i++)
+    array_push (bash_argv_a, l->word->word);
+
+  t = itos (i);
+  array_push (bash_argc_a, t);
+  free (t);
+#endif /* ARRAY_VARS && DEBUGGER */
+}
+
+/* Remove arguments from BASH_ARGV array.  Pop top element off BASH_ARGC
+   array and use that value as the count of elements to remove from
+   BASH_ARGV. */
+void
+pop_args ()
+{
+#if defined (ARRAY_VARS) && defined (DEBUGGER)
+  SHELL_VAR *bash_argv_v, *bash_argc_v;
+  ARRAY *bash_argv_a, *bash_argc_a;
+  ARRAY_ELEMENT *ce;
+  intmax_t i;
+
+  GET_ARRAY_FROM_VAR ("BASH_ARGV", bash_argv_v, bash_argv_a);
+  GET_ARRAY_FROM_VAR ("BASH_ARGC", bash_argc_v, bash_argc_a);
+
+  ce = array_unshift_element (bash_argc_a);
+  if (ce == 0 || legal_number (element_value (ce), &i) == 0)
+    i = 0;
+
+  for ( ; i > 0; i--)
+    array_pop (bash_argv_a);
+  array_dispose_element (ce);
+#endif /* ARRAY_VARS && DEBUGGER */
+}
+
+/*************************************************
+ *						 *
+ *	Functions to manage special variables	 *
+ *						 *
+ *************************************************/
+
+/* Extern declarations for variables this code has to manage. */
+
+/* An alist of name.function for each special variable.  Most of the
+   functions don't do much, and in fact, this would be faster with a
+   switch statement, but by the end of this file, I am sick of switch
+   statements. */
+
+#define SET_INT_VAR(name, intvar)  intvar = find_variable (name) != 0
+
+/* This table will be sorted with qsort() the first time it's accessed. */
+struct name_and_function {
+  char *name;
+  sh_sv_func_t *function;
+};
+
+static struct name_and_function special_vars[] = {
+  { "BASH_COMPAT", sv_shcompat },
+  { "BASH_XTRACEFD", sv_xtracefd },
+
+#if defined (JOB_CONTROL)
+  { "CHILD_MAX", sv_childmax },
+#endif
+
+#if defined (READLINE)
+#  if defined (STRICT_POSIX)
+  { "COLUMNS", sv_winsize },
+#  endif
+  { "COMP_WORDBREAKS", sv_comp_wordbreaks },
+#endif
+
+  { "EXECIGNORE", sv_execignore },
+
+  { "FUNCNEST", sv_funcnest },
+
+  { "GLOBIGNORE", sv_globignore },
+
+#if defined (HISTORY)
+  { "HISTCONTROL", sv_history_control },
+  { "HISTFILESIZE", sv_histsize },
+  { "HISTIGNORE", sv_histignore },
+  { "HISTSIZE", sv_histsize },
+  { "HISTTIMEFORMAT", sv_histtimefmt },
+#endif
+
+#if defined (__CYGWIN__)
+  { "HOME", sv_home },
+#endif
+
+#if defined (READLINE)
+  { "HOSTFILE", sv_hostfile },
+#endif
+
+  { "IFS", sv_ifs },
+  { "IGNOREEOF", sv_ignoreeof },
+
+  { "LANG", sv_locale },
+  { "LC_ALL", sv_locale },
+  { "LC_COLLATE", sv_locale },
+  { "LC_CTYPE", sv_locale },
+  { "LC_MESSAGES", sv_locale },
+  { "LC_NUMERIC", sv_locale },
+  { "LC_TIME", sv_locale },
+
+#if defined (READLINE) && defined (STRICT_POSIX)
+  { "LINES", sv_winsize },
+#endif
+
+  { "MAIL", sv_mail },
+  { "MAILCHECK", sv_mail },
+  { "MAILPATH", sv_mail },
+
+  { "OPTERR", sv_opterr },
+  { "OPTIND", sv_optind },
+
+  { "PATH", sv_path },
+  { "POSIXLY_CORRECT", sv_strict_posix },
+
+#if defined (READLINE)
+  { "TERM", sv_terminal },
+  { "TERMCAP", sv_terminal },
+  { "TERMINFO", sv_terminal },
+#endif /* READLINE */
+
+  { "TEXTDOMAIN", sv_locale },
+  { "TEXTDOMAINDIR", sv_locale },
+
+#if defined (HAVE_TZSET)
+  { "TZ", sv_tz },
+#endif
+
+#if defined (HISTORY) && defined (BANG_HISTORY)
+  { "histchars", sv_histchars },
+#endif /* HISTORY && BANG_HISTORY */
+
+  { "ignoreeof", sv_ignoreeof },
+
+  { (char *)0, (sh_sv_func_t *)0 }
+};
+
+#define N_SPECIAL_VARS	(sizeof (special_vars) / sizeof (special_vars[0]) - 1)
+
+static int
+sv_compare (sv1, sv2)
+     struct name_and_function *sv1, *sv2;
+{
+  int r;
+
+  if ((r = sv1->name[0] - sv2->name[0]) == 0)
+    r = strcmp (sv1->name, sv2->name);
+  return r;
+}
+
+static inline int
+find_special_var (name)
+     const char *name;
+{
+  register int i, r;
+
+  for (i = 0; special_vars[i].name; i++)
+    {
+      r = special_vars[i].name[0] - name[0];
+      if (r == 0)
+	r = strcmp (special_vars[i].name, name);
+      if (r == 0)
+	return i;
+      else if (r > 0)
+	/* Can't match any of rest of elements in sorted list.  Take this out
+	   if it causes problems in certain environments. */
+	break;
+    }
+  return -1;
+}
+
+/* The variable in NAME has just had its state changed.  Check to see if it
+   is one of the special ones where something special happens. */
+void
+stupidly_hack_special_variables (name)
+     char *name;
+{
+  static int sv_sorted = 0;
+  int i;
+
+  if (sv_sorted == 0)	/* shouldn't need, but it's fairly cheap. */
+    {
+      qsort (special_vars, N_SPECIAL_VARS, sizeof (special_vars[0]),
+		(QSFUNC *)sv_compare);
+      sv_sorted = 1;
+    }
+
+  i = find_special_var (name);
+  if (i != -1)
+    (*(special_vars[i].function)) (name);
+}
+
+/* Special variables that need hooks to be run when they are unset as part
+   of shell reinitialization should have their sv_ functions run here. */
+void
+reinit_special_variables ()
+{
+#if defined (READLINE)
+  sv_comp_wordbreaks ("COMP_WORDBREAKS");
+#endif
+  sv_globignore ("GLOBIGNORE");
+  sv_opterr ("OPTERR");
+}
+
+void
+sv_ifs (name)
+     char *name;
+{
+  SHELL_VAR *v;
+
+  v = find_variable ("IFS");
+  setifs (v);
+}
+
+/* What to do just after the PATH variable has changed. */
+void
+sv_path (name)
+     char *name;
+{
+  /* hash -r */
+  phash_flush ();
+}
+
+/* What to do just after one of the MAILxxxx variables has changed.  NAME
+   is the name of the variable.  This is called with NAME set to one of
+   MAIL, MAILCHECK, or MAILPATH.  */
+void
+sv_mail (name)
+     char *name;
+{
+  /* If the time interval for checking the files has changed, then
+     reset the mail timer.  Otherwise, one of the pathname vars
+     to the users mailbox has changed, so rebuild the array of
+     filenames. */
+  if (name[4] == 'C')  /* if (strcmp (name, "MAILCHECK") == 0) */
+    reset_mail_timer ();
+  else
+    {
+      free_mail_files ();
+      remember_mail_dates ();
+    }
+}
+
+void
+sv_funcnest (name)
+     char *name;
+{
+  SHELL_VAR *v;
+  intmax_t num;
+
+  v = find_variable (name);
+  if (v == 0)
+    funcnest_max = 0;
+  else if (legal_number (value_cell (v), &num) == 0)
+    funcnest_max = 0;
+  else
+    funcnest_max = num;
+}
+
+/* What to do when EXECIGNORE changes. */
+void
+sv_execignore (name)
+     char *name;
+{
+  setup_exec_ignore (name);
+}
+
+/* What to do when GLOBIGNORE changes. */
+void
+sv_globignore (name)
+     char *name;
+{
+  if (privileged_mode == 0)
+    setup_glob_ignore (name);
+}
+
+#if defined (READLINE)
+void
+sv_comp_wordbreaks (name)
+     char *name;
+{
+  SHELL_VAR *sv;
+
+  sv = find_variable (name);
+  if (sv == 0)
+    reset_completer_word_break_chars ();
+}
+
+/* What to do just after one of the TERMxxx variables has changed.
+   If we are an interactive shell, then try to reset the terminal
+   information in readline. */
+void
+sv_terminal (name)
+     char *name;
+{
+  if (interactive_shell && no_line_editing == 0)
+    rl_reset_terminal (get_string_value ("TERM"));
+}
+
+void
+sv_hostfile (name)
+     char *name;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v == 0)
+    clear_hostname_list ();
+  else
+    hostname_list_initialized = 0;
+}
+
+#if defined (STRICT_POSIX)
+/* In strict posix mode, we allow assignments to LINES and COLUMNS (and values
+   found in the initial environment) to override the terminal size reported by
+   the kernel. */
+void
+sv_winsize (name)
+     char *name;
+{
+  SHELL_VAR *v;
+  intmax_t xd;
+  int d;
+
+  if (posixly_correct == 0 || interactive_shell == 0 || no_line_editing)
+    return;
+
+  v = find_variable (name);
+  if (v == 0 || var_isset (v) == 0)
+    rl_reset_screen_size ();
+  else
+    {
+      if (legal_number (value_cell (v), &xd) == 0)
+	return;
+      winsize_assignment = 1;
+      d = xd;			/* truncate */
+      if (name[0] == 'L')	/* LINES */
+	rl_set_screen_size (d, -1);
+      else			/* COLUMNS */
+	rl_set_screen_size (-1, d);
+      winsize_assignment = 0;
+    }
+}
+#endif /* STRICT_POSIX */
+#endif /* READLINE */
+
+/* Update the value of HOME in the export environment so tilde expansion will
+   work on cygwin. */
+#if defined (__CYGWIN__)
+sv_home (name)
+     char *name;
+{
+  array_needs_making = 1;
+  maybe_make_export_env ();
+}
+#endif
+
+#if defined (HISTORY)
+/* What to do after the HISTSIZE or HISTFILESIZE variables change.
+   If there is a value for this HISTSIZE (and it is numeric), then stifle
+   the history.  Otherwise, if there is NO value for this variable,
+   unstifle the history.  If name is HISTFILESIZE, and its value is
+   numeric, truncate the history file to hold no more than that many
+   lines. */
+void
+sv_histsize (name)
+     char *name;
+{
+  char *temp;
+  intmax_t num;
+  int hmax;
+
+  temp = get_string_value (name);
+
+  if (temp && *temp)
+    {
+      if (legal_number (temp, &num))
+	{
+	  hmax = num;
+	  if (hmax < 0 && name[4] == 'S')
+	    unstifle_history ();	/* unstifle history if HISTSIZE < 0 */
+	  else if (name[4] == 'S')
+	    {
+	      stifle_history (hmax);
+	      hmax = where_history ();
+	      if (history_lines_this_session > hmax)
+		history_lines_this_session = hmax;
+	    }
+	  else if (hmax >= 0)	/* truncate HISTFILE if HISTFILESIZE >= 0 */
+	    {
+	      history_truncate_file (get_string_value ("HISTFILE"), hmax);
+	      /* If we just shrank the history file to fewer lines than we've
+		 already read, make sure we adjust our idea of how many lines
+		 we have read from the file. */
+	      if (hmax < history_lines_in_file)
+		history_lines_in_file = hmax;
+	    }
+	}
+    }
+  else if (name[4] == 'S')
+    unstifle_history ();
+}
+
+/* What to do after the HISTIGNORE variable changes. */
+void
+sv_histignore (name)
+     char *name;
+{
+  setup_history_ignore (name);
+}
+
+/* What to do after the HISTCONTROL variable changes. */
+void
+sv_history_control (name)
+     char *name;
+{
+  char *temp;
+  char *val;
+  int tptr;
+
+  history_control = 0;
+  temp = get_string_value (name);
+
+  if (temp == 0 || *temp == 0)
+    return;
+
+  tptr = 0;
+  while (val = extract_colon_unit (temp, &tptr))
+    {
+      if (STREQ (val, "ignorespace"))
+	history_control |= HC_IGNSPACE;
+      else if (STREQ (val, "ignoredups"))
+	history_control |= HC_IGNDUPS;
+      else if (STREQ (val, "ignoreboth"))
+	history_control |= HC_IGNBOTH;
+      else if (STREQ (val, "erasedups"))
+	history_control |= HC_ERASEDUPS;
+
+      free (val);
+    }
+}
+
+#if defined (BANG_HISTORY)
+/* Setting/unsetting of the history expansion character. */
+void
+sv_histchars (name)
+     char *name;
+{
+  char *temp;
+
+  temp = get_string_value (name);
+  if (temp)
+    {
+      history_expansion_char = *temp;
+      if (temp[0] && temp[1])
+	{
+	  history_subst_char = temp[1];
+	  if (temp[2])
+	      history_comment_char = temp[2];
+	}
+    }
+  else
+    {
+      history_expansion_char = '!';
+      history_subst_char = '^';
+      history_comment_char = '#';
+    }
+}
+#endif /* BANG_HISTORY */
+
+void
+sv_histtimefmt (name)
+     char *name;
+{
+  SHELL_VAR *v;
+
+  if (v = find_variable (name))
+    {
+      if (history_comment_char == 0)
+	history_comment_char = '#';
+    }
+  history_write_timestamps = (v != 0);
+}
+#endif /* HISTORY */
+
+#if defined (HAVE_TZSET)
+void
+sv_tz (name)
+     char *name;
+{
+  SHELL_VAR *v;
+
+  v = find_variable (name);
+  if (v && exported_p (v))
+    array_needs_making = 1;
+  else if (v == 0)
+    array_needs_making = 1;
+
+  if (array_needs_making)
+    {
+      maybe_make_export_env ();  
+      tzset ();
+    }
+}
+#endif
+
+/* If the variable exists, then the value of it can be the number
+   of times we actually ignore the EOF.  The default is small,
+   (smaller than csh, anyway). */
+void
+sv_ignoreeof (name)
+     char *name;
+{
+  SHELL_VAR *tmp_var;
+  char *temp;
+
+  eof_encountered = 0;
+
+  tmp_var = find_variable (name);
+  ignoreeof = tmp_var && var_isset (tmp_var);
+  temp = tmp_var ? value_cell (tmp_var) : (char *)NULL;
+  if (temp)
+    eof_encountered_limit = (*temp && all_digits (temp)) ? atoi (temp) : 10;
+  set_shellopts ();	/* make sure `ignoreeof' is/is not in $SHELLOPTS */
+}
+
+void
+sv_optind (name)
+     char *name;
+{
+  SHELL_VAR *var;
+  char *tt;
+  int s;
+
+  var = find_variable ("OPTIND");
+  tt = var ? get_variable_value (var) : (char *)NULL;
+
+  /* Assume that if var->context < variable_context and variable_context > 0
+     then we are restoring the variables's previous state while returning
+     from a function. */
+  if (tt && *tt)
+    {
+      s = atoi (tt);
+
+      /* According to POSIX, setting OPTIND=1 resets the internal state
+	 of getopt (). */
+      if (s < 0 || s == 1)
+	s = 0;
+    }
+  else
+    s = 0;
+  getopts_reset (s);
+}
+
+void
+sv_opterr (name)
+     char *name;
+{
+  char *tt;
+
+  tt = get_string_value ("OPTERR");
+  sh_opterr = (tt && *tt) ? atoi (tt) : 1;
+}
+
+void
+sv_strict_posix (name)
+     char *name;
+{
+  SHELL_VAR *var;
+
+  var = find_variable (name);
+  posixly_correct = var && var_isset (var);
+  posix_initialize (posixly_correct);
+#if defined (READLINE)
+  if (interactive_shell)
+    posix_readline_initialize (posixly_correct);
+#endif /* READLINE */
+  set_shellopts ();	/* make sure `posix' is/is not in $SHELLOPTS */
+}
+
+void
+sv_locale (name)
+     char *name;
+{
+  char *v;
+  int r;
+
+  v = get_string_value (name);
+  if (name[0] == 'L' && name[1] == 'A')	/* LANG */
+    r = set_lang (name, v);
+  else
+    r = set_locale_var (name, v);		/* LC_*, TEXTDOMAIN* */
+
+#if 1
+  if (r == 0 && posixly_correct)
+    set_exit_status (EXECUTION_FAILURE);
+#endif
+}
+
+#if defined (ARRAY_VARS)
+void
+set_pipestatus_array (ps, nproc)
+     int *ps;
+     int nproc;
+{
+  SHELL_VAR *v;
+  ARRAY *a;
+  ARRAY_ELEMENT *ae;
+  register int i;
+  char *t, tbuf[INT_STRLEN_BOUND(int) + 1];
+
+  v = find_variable ("PIPESTATUS");
+  if (v == 0)
+    v = make_new_array_variable ("PIPESTATUS");
+  if (array_p (v) == 0)
+    return;		/* Do nothing if not an array variable. */
+  a = array_cell (v);
+
+  if (a == 0 || array_num_elements (a) == 0)
+    {
+      for (i = 0; i < nproc; i++)	/* was ps[i] != -1, not i < nproc */
+	{
+	  t = inttostr (ps[i], tbuf, sizeof (tbuf));
+	  array_insert (a, i, t);
+	}
+      return;
+    }
+
+  /* Fast case */
+  if (array_num_elements (a) == nproc && nproc == 1)
+    {
+#ifndef ALT_ARRAY_IMPLEMENTATION
+      ae = element_forw (a->head);
+#else
+      ae = a->elements[0];
+#endif
+      ARRAY_ELEMENT_REPLACE (ae, itos (ps[0]));
+    }
+  else if (array_num_elements (a) <= nproc)
+    {
+      /* modify in array_num_elements members in place, then add */
+#ifndef ALT_ARRAY_IMPLEMENTATION
+      ae = a->head;
+#endif
+      for (i = 0; i < array_num_elements (a); i++)
+	{
+#ifndef ALT_ARRAY_IMPLEMENTATION
+	  ae = element_forw (ae);
+#else
+	  ae = a->elements[i];
+#endif
+	  ARRAY_ELEMENT_REPLACE (ae, itos (ps[i]));
+	}
+      /* add any more */
+      for ( ; i < nproc; i++)
+	{
+	  t = inttostr (ps[i], tbuf, sizeof (tbuf));
+	  array_insert (a, i, t);
+	}
+    }
+  else
+    {
+#ifndef ALT_ARRAY_IMPLEMENTATION
+      /* deleting elements.  it's faster to rebuild the array. */	  
+      array_flush (a);
+      for (i = 0; i < nproc; i++)
+	{
+	  t = inttostr (ps[i], tbuf, sizeof (tbuf));
+	  array_insert (a, i, t);
+	}
+#else
+      /* deleting elements. replace the first NPROC, free the rest */
+      for (i = 0; i < nproc; i++)
+	{
+	  ae = a->elements[i];
+	  ARRAY_ELEMENT_REPLACE (ae, itos (ps[i]));
+	}
+      for ( ; i <= array_max_index (a); i++)
+	{
+	  array_dispose_element (a->elements[i]);
+	  a->elements[i] = (ARRAY_ELEMENT *)NULL;
+	}
+
+      /* bookkeeping usually taken care of by array_insert */
+      set_max_index (a, nproc - 1);
+      set_first_index (a, 0);
+      set_num_elements (a, nproc);
+#endif /* ALT_ARRAY_IMPLEMENTATION */
+    }
+}
+
+ARRAY *
+save_pipestatus_array ()
+{
+  SHELL_VAR *v;
+  ARRAY *a;
+
+  v = find_variable ("PIPESTATUS");
+  if (v == 0 || array_p (v) == 0 || array_cell (v) == 0)
+    return ((ARRAY *)NULL);
+    
+  a = array_copy (array_cell (v));
+
+  return a;
+}
+
+void
+restore_pipestatus_array (a)
+     ARRAY *a;
+{
+  SHELL_VAR *v;
+  ARRAY *a2;
+
+  v = find_variable ("PIPESTATUS");
+  /* XXX - should we still assign even if existing value is NULL? */
+  if (v == 0 || array_p (v) == 0 || array_cell (v) == 0)
+    return;
+
+  a2 = array_cell (v);
+  var_setarray (v, a); 
+
+  array_dispose (a2);
+}
+#endif
+
+void
+set_pipestatus_from_exit (s)
+     int s;
+{
+#if defined (ARRAY_VARS)
+  static int v[2] = { 0, -1 };
+
+  v[0] = s;
+  set_pipestatus_array (v, 1);
+#endif
+}
+
+void
+sv_xtracefd (name)
+     char *name;
+{
+  SHELL_VAR *v;
+  char *t, *e;
+  int fd;
+  FILE *fp;
+
+  v = find_variable (name);
+  if (v == 0)
+    {
+      xtrace_reset ();
+      return;
+    }
+
+  t = value_cell (v);
+  if (t == 0 || *t == 0)
+    xtrace_reset ();
+  else
+    {
+      fd = (int)strtol (t, &e, 10);
+      if (e != t && *e == '\0' && sh_validfd (fd))
+	{
+	  fp = fdopen (fd, "w");
+	  if (fp == 0)
+	    internal_error (_("%s: %s: cannot open as FILE"), name, value_cell (v));
+	  else
+	    xtrace_set (fd, fp);
+	}
+      else
+	internal_error (_("%s: %s: invalid value for trace file descriptor"), name, value_cell (v));
+    }
+}
+
+#define MIN_COMPAT_LEVEL 31
+
+void
+sv_shcompat (name)
+     char *name;
+{
+  SHELL_VAR *v;
+  char *val;
+  int tens, ones, compatval;
+
+  v = find_variable (name);
+  if (v == 0)
+    {
+      shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+      set_compatibility_opts ();
+      return;
+    }
+  val = value_cell (v);
+  if (val == 0 || *val == '\0')
+    {
+      shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+      set_compatibility_opts ();
+      return;
+    }
+  /* Handle decimal-like compatibility version specifications: 4.2 */
+  if (ISDIGIT (val[0]) && val[1] == '.' && ISDIGIT (val[2]) && val[3] == 0)
+    {
+      tens = val[0] - '0';
+      ones = val[2] - '0';
+      compatval = tens*10 + ones;
+    }
+  /* Handle integer-like compatibility version specifications: 42 */
+  else if (ISDIGIT (val[0]) && ISDIGIT (val[1]) && val[2] == 0)
+    {
+      tens = val[0] - '0';
+      ones = val[1] - '0';
+      compatval = tens*10 + ones;
+    }
+  else
+    {
+compat_error:
+      internal_error (_("%s: %s: compatibility value out of range"), name, val);
+      shell_compatibility_level = DEFAULT_COMPAT_LEVEL;
+      set_compatibility_opts ();
+      return;
+    }
+
+  if (compatval < MIN_COMPAT_LEVEL || compatval > DEFAULT_COMPAT_LEVEL)
+    goto compat_error;
+
+  shell_compatibility_level = compatval;
+  set_compatibility_opts ();
+}
+
+#if defined (JOB_CONTROL)
+void
+sv_childmax (name)
+     char *name;
+{
+  char *tt;
+  int s;
+
+  tt = get_string_value (name);
+  s = (tt && *tt) ? atoi (tt) : 0;
+  set_maxchild (s);
+}
+#endif