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+This file is set.def, from which is created set.c.
+It implements the "set" and "unset" builtins in Bash.
+
+Copyright (C) 1987-2018 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/>.
+
+$PRODUCES set.c
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+# ifdef _MINIX
+# include <sys/types.h>
+# endif
+# include <unistd.h>
+#endif
+
+#include <stdio.h>
+
+#include "../bashansi.h"
+#include "../bashintl.h"
+
+#include "../shell.h"
+#include "../parser.h"
+#include "../flags.h"
+#include "common.h"
+#include "bashgetopt.h"
+
+#if defined (READLINE)
+# include "../input.h"
+# include "../bashline.h"
+# include <readline/readline.h>
+#endif
+
+#if defined (HISTORY)
+# include "../bashhist.h"
+#endif
+
+$BUILTIN set
+$FUNCTION set_builtin
+$SHORT_DOC set [-abefhkmnptuvxBCHP] [-o option-name] [--] [arg ...]
+Set or unset values of shell options and positional parameters.
+
+Change the value of shell attributes and positional parameters, or
+display the names and values of shell variables.
+
+Options:
+ -a Mark variables which are modified or created for export.
+ -b Notify of job termination immediately.
+ -e Exit immediately if a command exits with a non-zero status.
+ -f Disable file name generation (globbing).
+ -h Remember the location of commands as they are looked up.
+ -k All assignment arguments are placed in the environment for a
+ command, not just those that precede the command name.
+ -m Job control is enabled.
+ -n Read commands but do not execute them.
+ -o option-name
+ Set the variable corresponding to option-name:
+ allexport same as -a
+ braceexpand same as -B
+#if defined (READLINE)
+ emacs use an emacs-style line editing interface
+#endif /* READLINE */
+ errexit same as -e
+ errtrace same as -E
+ functrace same as -T
+ hashall same as -h
+#if defined (BANG_HISTORY)
+ histexpand same as -H
+#endif /* BANG_HISTORY */
+#if defined (HISTORY)
+ history enable command history
+#endif
+ ignoreeof the shell will not exit upon reading EOF
+ interactive-comments
+ allow comments to appear in interactive commands
+ keyword same as -k
+#if defined (JOB_CONTROL)
+ monitor same as -m
+#endif
+ noclobber same as -C
+ noexec same as -n
+ noglob same as -f
+ nolog currently accepted but ignored
+#if defined (JOB_CONTROL)
+ notify same as -b
+#endif
+ nounset same as -u
+ onecmd same as -t
+ physical same as -P
+ pipefail the return value of a pipeline is the status of
+ the last command to exit with a non-zero status,
+ or zero if no command exited with a non-zero status
+ posix change the behavior of bash where the default
+ operation differs from the Posix standard to
+ match the standard
+ privileged same as -p
+ verbose same as -v
+#if defined (READLINE)
+ vi use a vi-style line editing interface
+#endif /* READLINE */
+ xtrace same as -x
+ -p Turned on whenever the real and effective user ids do not match.
+ Disables processing of the $ENV file and importing of shell
+ functions. Turning this option off causes the effective uid and
+ gid to be set to the real uid and gid.
+ -t Exit after reading and executing one command.
+ -u Treat unset variables as an error when substituting.
+ -v Print shell input lines as they are read.
+ -x Print commands and their arguments as they are executed.
+#if defined (BRACE_EXPANSION)
+ -B the shell will perform brace expansion
+#endif /* BRACE_EXPANSION */
+ -C If set, disallow existing regular files to be overwritten
+ by redirection of output.
+ -E If set, the ERR trap is inherited by shell functions.
+#if defined (BANG_HISTORY)
+ -H Enable ! style history substitution. This flag is on
+ by default when the shell is interactive.
+#endif /* BANG_HISTORY */
+ -P If set, do not resolve symbolic links when executing commands
+ such as cd which change the current directory.
+ -T If set, the DEBUG and RETURN traps are inherited by shell functions.
+ -- Assign any remaining arguments to the positional parameters.
+ If there are no remaining arguments, the positional parameters
+ are unset.
+ - Assign any remaining arguments to the positional parameters.
+ The -x and -v options are turned off.
+
+Using + rather than - causes these flags to be turned off. The
+flags can also be used upon invocation of the shell. The current
+set of flags may be found in $-. The remaining n ARGs are positional
+parameters and are assigned, in order, to $1, $2, .. $n. If no
+ARGs are given, all shell variables are printed.
+
+Exit Status:
+Returns success unless an invalid option is given.
+$END
+
+typedef int setopt_set_func_t __P((int, char *));
+typedef int setopt_get_func_t __P((char *));
+
+static int find_minus_o_option __P((char *));
+
+static void print_minus_o_option __P((char *, int, int));
+static void print_all_shell_variables __P((void));
+
+static int set_ignoreeof __P((int, char *));
+static int set_posix_mode __P((int, char *));
+
+#if defined (READLINE)
+static int set_edit_mode __P((int, char *));
+static int get_edit_mode __P((char *));
+#endif
+
+#if defined (HISTORY)
+static int bash_set_history __P((int, char *));
+#endif
+
+static const char * const on = "on";
+static const char * const off = "off";
+
+static int previous_option_value;
+
+/* A struct used to match long options for set -o to the corresponding
+ option letter or internal variable. The functions can be called to
+ dynamically generate values. If you add a new variable name here
+ that doesn't have a corresponding single-character option letter, make
+ sure to set the value appropriately in reset_shell_options. */
+const struct {
+ char *name;
+ int letter;
+ int *variable;
+ setopt_set_func_t *set_func;
+ setopt_get_func_t *get_func;
+} o_options[] = {
+ { "allexport", 'a', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#if defined (BRACE_EXPANSION)
+ { "braceexpand",'B', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#endif
+#if defined (READLINE)
+ { "emacs", '\0', (int *)NULL, set_edit_mode, get_edit_mode },
+#endif
+ { "errexit", 'e', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "errtrace", 'E', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "functrace", 'T', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "hashall", 'h', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#if defined (BANG_HISTORY)
+ { "histexpand", 'H', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#endif /* BANG_HISTORY */
+#if defined (HISTORY)
+ { "history", '\0', &enable_history_list, bash_set_history, (setopt_get_func_t *)NULL },
+#endif
+ { "ignoreeof", '\0', &ignoreeof, set_ignoreeof, (setopt_get_func_t *)NULL },
+ { "interactive-comments", '\0', &interactive_comments, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "keyword", 'k', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#if defined (JOB_CONTROL)
+ { "monitor", 'm', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#endif
+ { "noclobber", 'C', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "noexec", 'n', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "noglob", 'f', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#if defined (HISTORY)
+ { "nolog", '\0', &dont_save_function_defs, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#endif
+#if defined (JOB_CONTROL)
+ { "notify", 'b', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#endif /* JOB_CONTROL */
+ { "nounset", 'u', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "onecmd", 't', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "physical", 'P', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "pipefail", '\0', &pipefail_opt, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "posix", '\0', &posixly_correct, set_posix_mode, (setopt_get_func_t *)NULL },
+ { "privileged", 'p', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ { "verbose", 'v', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+#if defined (READLINE)
+ { "vi", '\0', (int *)NULL, set_edit_mode, get_edit_mode },
+#endif
+ { "xtrace", 'x', (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+ {(char *)NULL, 0 , (int *)NULL, (setopt_set_func_t *)NULL, (setopt_get_func_t *)NULL },
+};
+
+#define N_O_OPTIONS (sizeof (o_options) / sizeof (o_options[0]))
+
+#define GET_BINARY_O_OPTION_VALUE(i, name) \
+ ((o_options[i].get_func) ? (*o_options[i].get_func) (name) \
+ : (*o_options[i].variable))
+
+#define SET_BINARY_O_OPTION_VALUE(i, onoff, name) \
+ ((o_options[i].set_func) ? (*o_options[i].set_func) (onoff, name) \
+ : (*o_options[i].variable = (onoff == FLAG_ON)))
+
+static int
+find_minus_o_option (name)
+ char *name;
+{
+ register int i;
+
+ for (i = 0; o_options[i].name; i++)
+ if (STREQ (name, o_options[i].name))
+ return i;
+ return -1;
+}
+
+int
+minus_o_option_value (name)
+ char *name;
+{
+ register int i;
+ int *on_or_off;
+
+ i = find_minus_o_option (name);
+ if (i < 0)
+ return (-1);
+
+ if (o_options[i].letter)
+ {
+ on_or_off = find_flag (o_options[i].letter);
+ return ((on_or_off == FLAG_UNKNOWN) ? -1 : *on_or_off);
+ }
+ else
+ return (GET_BINARY_O_OPTION_VALUE (i, name));
+}
+
+#define MINUS_O_FORMAT "%-15s\t%s\n"
+
+static void
+print_minus_o_option (name, value, pflag)
+ char *name;
+ int value, pflag;
+{
+ if (pflag == 0)
+ printf (MINUS_O_FORMAT, name, value ? on : off);
+ else
+ printf ("set %co %s\n", value ? '-' : '+', name);
+}
+
+void
+list_minus_o_opts (mode, reusable)
+ int mode, reusable;
+{
+ register int i;
+ int *on_or_off, value;
+
+ for (i = 0; o_options[i].name; i++)
+ {
+ if (o_options[i].letter)
+ {
+ value = 0;
+ on_or_off = find_flag (o_options[i].letter);
+ if (on_or_off == FLAG_UNKNOWN)
+ on_or_off = &value;
+ if (mode == -1 || mode == *on_or_off)
+ print_minus_o_option (o_options[i].name, *on_or_off, reusable);
+ }
+ else
+ {
+ value = GET_BINARY_O_OPTION_VALUE (i, o_options[i].name);
+ if (mode == -1 || mode == value)
+ print_minus_o_option (o_options[i].name, value, reusable);
+ }
+ }
+}
+
+char **
+get_minus_o_opts ()
+{
+ char **ret;
+ int i;
+
+ ret = strvec_create (N_O_OPTIONS + 1);
+ for (i = 0; o_options[i].name; i++)
+ ret[i] = o_options[i].name;
+ ret[i] = (char *)NULL;
+ return ret;
+}
+
+char *
+get_current_options ()
+{
+ char *temp;
+ int i, posixopts;
+
+ posixopts = num_posix_options (); /* shopts modified by posix mode */
+ /* Make the buffer big enough to hold the set -o options and the shopt
+ options modified by posix mode. */
+ temp = (char *)xmalloc (1 + N_O_OPTIONS + posixopts);
+ for (i = 0; o_options[i].name; i++)
+ {
+ if (o_options[i].letter)
+ temp[i] = *(find_flag (o_options[i].letter));
+ else
+ temp[i] = GET_BINARY_O_OPTION_VALUE (i, o_options[i].name);
+ }
+
+ /* Add the shell options that are modified by posix mode to the end of the
+ bitmap. They will be handled in set_current_options() */
+ get_posix_options (temp+i);
+ temp[i+posixopts] = '\0';
+ return (temp);
+}
+
+void
+set_current_options (bitmap)
+ const char *bitmap;
+{
+ int i;
+
+ if (bitmap == 0)
+ return;
+
+ for (i = 0; o_options[i].name; i++)
+ {
+ if (o_options[i].letter)
+ change_flag (o_options[i].letter, bitmap[i] ? FLAG_ON : FLAG_OFF);
+ else
+ SET_BINARY_O_OPTION_VALUE (i, bitmap[i] ? FLAG_ON : FLAG_OFF, o_options[i].name);
+ }
+
+ /* Now reset the variables changed by posix mode */
+ set_posix_options (bitmap+i);
+}
+
+static int
+set_ignoreeof (on_or_off, option_name)
+ int on_or_off;
+ char *option_name;
+{
+ ignoreeof = on_or_off == FLAG_ON;
+ unbind_variable_noref ("ignoreeof");
+ if (ignoreeof)
+ bind_variable ("IGNOREEOF", "10", 0);
+ else
+ unbind_variable_noref ("IGNOREEOF");
+ sv_ignoreeof ("IGNOREEOF");
+ return 0;
+}
+
+static int
+set_posix_mode (on_or_off, option_name)
+ int on_or_off;
+ char *option_name;
+{
+ posixly_correct = on_or_off == FLAG_ON;
+ if (posixly_correct == 0)
+ unbind_variable_noref ("POSIXLY_CORRECT");
+ else
+ bind_variable ("POSIXLY_CORRECT", "y", 0);
+ sv_strict_posix ("POSIXLY_CORRECT");
+ return (0);
+}
+
+#if defined (READLINE)
+/* Magic. This code `knows' how readline handles rl_editing_mode. */
+static int
+set_edit_mode (on_or_off, option_name)
+ int on_or_off;
+ char *option_name;
+{
+ int isemacs;
+
+ if (on_or_off == FLAG_ON)
+ {
+ rl_variable_bind ("editing-mode", option_name);
+
+ if (interactive)
+ with_input_from_stdin ();
+ no_line_editing = 0;
+ }
+ else
+ {
+ isemacs = rl_editing_mode == 1;
+ if ((isemacs && *option_name == 'e') || (!isemacs && *option_name == 'v'))
+ {
+ if (interactive)
+ with_input_from_stream (stdin, "stdin");
+ no_line_editing = 1;
+ }
+ }
+ return 1-no_line_editing;
+}
+
+static int
+get_edit_mode (name)
+ char *name;
+{
+ return (*name == 'e' ? no_line_editing == 0 && rl_editing_mode == 1
+ : no_line_editing == 0 && rl_editing_mode == 0);
+}
+#endif /* READLINE */
+
+#if defined (HISTORY)
+static int
+bash_set_history (on_or_off, option_name)
+ int on_or_off;
+ char *option_name;
+{
+ if (on_or_off == FLAG_ON)
+ {
+ enable_history_list = 1;
+ bash_history_enable ();
+ if (history_lines_this_session == 0)
+ load_history ();
+ }
+ else
+ {
+ enable_history_list = 0;
+ bash_history_disable ();
+ }
+ return (1 - enable_history_list);
+}
+#endif
+
+int
+set_minus_o_option (on_or_off, option_name)
+ int on_or_off;
+ char *option_name;
+{
+ register int i;
+
+ i = find_minus_o_option (option_name);
+ if (i < 0)
+ {
+ sh_invalidoptname (option_name);
+ return (EX_USAGE);
+ }
+
+ if (o_options[i].letter == 0)
+ {
+ previous_option_value = GET_BINARY_O_OPTION_VALUE (i, o_options[i].name);
+ SET_BINARY_O_OPTION_VALUE (i, on_or_off, option_name);
+ return (EXECUTION_SUCCESS);
+ }
+ else
+ {
+ if ((previous_option_value = change_flag (o_options[i].letter, on_or_off)) == FLAG_ERROR)
+ {
+ sh_invalidoptname (option_name);
+ return (EXECUTION_FAILURE);
+ }
+ else
+ return (EXECUTION_SUCCESS);
+ }
+}
+
+static void
+print_all_shell_variables ()
+{
+ SHELL_VAR **vars;
+
+ vars = all_shell_variables ();
+ if (vars)
+ {
+ print_var_list (vars);
+ free (vars);
+ }
+
+ /* POSIX.2 does not allow function names and definitions to be output when
+ `set' is invoked without options (PASC Interp #202). */
+ if (posixly_correct == 0)
+ {
+ vars = all_shell_functions ();
+ if (vars)
+ {
+ print_func_list (vars);
+ free (vars);
+ }
+ }
+}
+
+void
+set_shellopts ()
+{
+ char *value;
+ char tflag[N_O_OPTIONS];
+ int vsize, i, vptr, *ip, exported;
+ SHELL_VAR *v;
+
+ for (vsize = i = 0; o_options[i].name; i++)
+ {
+ tflag[i] = 0;
+ if (o_options[i].letter)
+ {
+ ip = find_flag (o_options[i].letter);
+ if (ip && *ip)
+ {
+ vsize += strlen (o_options[i].name) + 1;
+ tflag[i] = 1;
+ }
+ }
+ else if (GET_BINARY_O_OPTION_VALUE (i, o_options[i].name))
+ {
+ vsize += strlen (o_options[i].name) + 1;
+ tflag[i] = 1;
+ }
+ }
+
+ value = (char *)xmalloc (vsize + 1);
+
+ for (i = vptr = 0; o_options[i].name; i++)
+ {
+ if (tflag[i])
+ {
+ strcpy (value + vptr, o_options[i].name);
+ vptr += strlen (o_options[i].name);
+ value[vptr++] = ':';
+ }
+ }
+
+ if (vptr)
+ vptr--; /* cut off trailing colon */
+ value[vptr] = '\0';
+
+ v = find_variable ("SHELLOPTS");
+
+ /* Turn off the read-only attribute so we can bind the new value, and
+ note whether or not the variable was exported. */
+ if (v)
+ {
+ VUNSETATTR (v, att_readonly);
+ exported = exported_p (v);
+ }
+ else
+ exported = 0;
+
+ v = bind_variable ("SHELLOPTS", value, 0);
+
+ /* Turn the read-only attribute back on, and turn off the export attribute
+ if it was set implicitly by mark_modified_vars and SHELLOPTS was not
+ exported before we bound the new value. */
+ VSETATTR (v, att_readonly);
+ if (mark_modified_vars && exported == 0 && exported_p (v))
+ VUNSETATTR (v, att_exported);
+
+ free (value);
+}
+
+void
+parse_shellopts (value)
+ char *value;
+{
+ char *vname;
+ int vptr;
+
+ vptr = 0;
+ while (vname = extract_colon_unit (value, &vptr))
+ {
+ set_minus_o_option (FLAG_ON, vname);
+ free (vname);
+ }
+}
+
+void
+initialize_shell_options (no_shellopts)
+ int no_shellopts;
+{
+ char *temp;
+ SHELL_VAR *var;
+
+ if (no_shellopts == 0)
+ {
+ var = find_variable ("SHELLOPTS");
+ /* set up any shell options we may have inherited. */
+ if (var && imported_p (var))
+ {
+ temp = (array_p (var) || assoc_p (var)) ? (char *)NULL : savestring (value_cell (var));
+ if (temp)
+ {
+ parse_shellopts (temp);
+ free (temp);
+ }
+ }
+ }
+
+ /* Set up the $SHELLOPTS variable. */
+ set_shellopts ();
+}
+
+/* Reset the values of the -o options that are not also shell flags. This is
+ called from execute_cmd.c:initialize_subshell() when setting up a subshell
+ to run an executable shell script without a leading `#!'. */
+void
+reset_shell_options ()
+{
+ pipefail_opt = 0;
+ ignoreeof = 0;
+
+#if defined (STRICT_POSIX)
+ posixly_correct = 1;
+#else
+ posixly_correct = 0;
+#endif
+#if defined (HISTORY)
+ dont_save_function_defs = 0;
+ remember_on_history = enable_history_list = 1;
+#endif
+}
+
+/* Set some flags from the word values in the input list. If LIST is empty,
+ then print out the values of the variables instead. If LIST contains
+ non-flags, then set $1 - $9 to the successive words of LIST. */
+int
+set_builtin (list)
+ WORD_LIST *list;
+{
+ int on_or_off, flag_name, force_assignment, opts_changed, rv, r;
+ register char *arg;
+ char s[3];
+
+ if (list == 0)
+ {
+ print_all_shell_variables ();
+ return (sh_chkwrite (EXECUTION_SUCCESS));
+ }
+
+ /* Check validity of flag arguments. */
+ rv = EXECUTION_SUCCESS;
+ reset_internal_getopt ();
+ while ((flag_name = internal_getopt (list, optflags)) != -1)
+ {
+ switch (flag_name)
+ {
+ case 'i': /* don't allow set -i */
+ s[0] = list_opttype;
+ s[1] = 'i';
+ s[2] = '\0';
+ sh_invalidopt (s);
+ builtin_usage ();
+ return (EX_USAGE);
+ CASE_HELPOPT;
+ case '?':
+ builtin_usage ();
+ return (list_optopt == '?' ? EXECUTION_SUCCESS : EX_USAGE);
+ default:
+ break;
+ }
+ }
+
+ /* Do the set command. While the list consists of words starting with
+ '-' or '+' treat them as flags, otherwise, start assigning them to
+ $1 ... $n. */
+ for (force_assignment = opts_changed = 0; list; )
+ {
+ arg = list->word->word;
+
+ /* If the argument is `--' or `-' then signal the end of the list
+ and remember the remaining arguments. */
+ if (arg[0] == '-' && (!arg[1] || (arg[1] == '-' && !arg[2])))
+ {
+ list = list->next;
+
+ /* `set --' unsets the positional parameters. */
+ if (arg[1] == '-')
+ force_assignment = 1;
+
+ /* Until told differently, the old shell behaviour of
+ `set - [arg ...]' being equivalent to `set +xv [arg ...]'
+ stands. Posix.2 says the behaviour is marked as obsolescent. */
+ else
+ {
+ change_flag ('x', '+');
+ change_flag ('v', '+');
+ opts_changed = 1;
+ }
+
+ break;
+ }
+
+ if ((on_or_off = *arg) && (on_or_off == '-' || on_or_off == '+'))
+ {
+ while (flag_name = *++arg)
+ {
+ if (flag_name == '?')
+ {
+ builtin_usage ();
+ return (EXECUTION_SUCCESS);
+ }
+ else if (flag_name == 'o') /* -+o option-name */
+ {
+ char *option_name;
+ WORD_LIST *opt;
+
+ opt = list->next;
+
+ if (opt == 0)
+ {
+ list_minus_o_opts (-1, (on_or_off == '+'));
+ rv = sh_chkwrite (rv);
+ continue;
+ }
+
+ option_name = opt->word->word;
+
+ if (option_name == 0 || *option_name == '\0' ||
+ *option_name == '-' || *option_name == '+')
+ {
+ list_minus_o_opts (-1, (on_or_off == '+'));
+ continue;
+ }
+ list = list->next; /* Skip over option name. */
+
+ opts_changed = 1;
+ if ((r = set_minus_o_option (on_or_off, option_name)) != EXECUTION_SUCCESS)
+ {
+ set_shellopts ();
+ return (r);
+ }
+ }
+ else if (change_flag (flag_name, on_or_off) == FLAG_ERROR)
+ {
+ s[0] = on_or_off;
+ s[1] = flag_name;
+ s[2] = '\0';
+ sh_invalidopt (s);
+ builtin_usage ();
+ set_shellopts ();
+ return (EXECUTION_FAILURE);
+ }
+ opts_changed = 1;
+ }
+ }
+ else
+ {
+ break;
+ }
+ list = list->next;
+ }
+
+ /* Assigning $1 ... $n */
+ if (list || force_assignment)
+ remember_args (list, 1);
+ /* Set up new value of $SHELLOPTS */
+ if (opts_changed)
+ set_shellopts ();
+ return (rv);
+}
+
+$BUILTIN unset
+$FUNCTION unset_builtin
+$SHORT_DOC unset [-f] [-v] [-n] [name ...]
+Unset values and attributes of shell variables and functions.
+
+For each NAME, remove the corresponding variable or function.
+
+Options:
+ -f treat each NAME as a shell function
+ -v treat each NAME as a shell variable
+ -n treat each NAME as a name reference and unset the variable itself
+ rather than the variable it references
+
+Without options, unset first tries to unset a variable, and if that fails,
+tries to unset a function.
+
+Some variables cannot be unset; also see `readonly'.
+
+Exit Status:
+Returns success unless an invalid option is given or a NAME is read-only.
+$END
+
+#define NEXT_VARIABLE() any_failed++; list = list->next; continue;
+
+int
+unset_builtin (list)
+ WORD_LIST *list;
+{
+ int unset_function, unset_variable, unset_array, opt, nameref, any_failed;
+ int global_unset_func, global_unset_var, vflags;
+ char *name, *tname;
+
+ unset_function = unset_variable = unset_array = nameref = any_failed = 0;
+ global_unset_func = global_unset_var = 0;
+
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "fnv")) != -1)
+ {
+ switch (opt)
+ {
+ case 'f':
+ global_unset_func = 1;
+ break;
+ case 'v':
+ global_unset_var = 1;
+ break;
+ case 'n':
+ nameref = 1;
+ break;
+ CASE_HELPOPT;
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
+ }
+ }
+
+ list = loptend;
+
+ if (global_unset_func && global_unset_var)
+ {
+ builtin_error (_("cannot simultaneously unset a function and a variable"));
+ return (EXECUTION_FAILURE);
+ }
+ else if (unset_function && nameref)
+ nameref = 0;
+
+#if defined (ARRAY_VARS)
+ vflags = assoc_expand_once ? (VA_NOEXPAND|VA_ONEWORD) : 0;
+#endif
+
+ while (list)
+ {
+ SHELL_VAR *var;
+ int tem;
+#if defined (ARRAY_VARS)
+ char *t;
+#endif
+
+ name = list->word->word;
+
+ unset_function = global_unset_func;
+ unset_variable = global_unset_var;
+
+#if defined (ARRAY_VARS)
+ unset_array = 0;
+ /* XXX valid array reference second arg was 0 */
+ if (!unset_function && nameref == 0 && valid_array_reference (name, vflags))
+ {
+ t = strchr (name, '[');
+ *t++ = '\0';
+ unset_array++;
+ }
+#endif
+ /* Get error checking out of the way first. The low-level functions
+ just perform the unset, relying on the caller to verify. */
+
+ /* Bash allows functions with names which are not valid identifiers
+ to be created when not in posix mode, so check only when in posix
+ mode when unsetting a function. */
+ if (((unset_function && posixly_correct) || !unset_function) && legal_identifier (name) == 0)
+ {
+ sh_invalidid (name);
+ NEXT_VARIABLE ();
+ }
+
+ /* Only search for functions here if -f supplied. */
+ var = unset_function ? find_function (name)
+ : (nameref ? find_variable_last_nameref (name, 0) : find_variable (name));
+
+ /* Some variables (but not functions yet) cannot be unset, period. */
+ if (var && unset_function == 0 && non_unsettable_p (var))
+ {
+ builtin_error (_("%s: cannot unset"), name);
+ NEXT_VARIABLE ();
+ }
+
+ /* if we have a nameref we want to use it */
+ if (var && unset_function == 0 && nameref == 0 && STREQ (name, name_cell(var)) == 0)
+ name = name_cell (var);
+
+ /* Posix.2 says try variables first, then functions. If we would
+ find a function after unsuccessfully searching for a variable,
+ note that we're acting on a function now as if -f were
+ supplied. The readonly check below takes care of it. */
+ if (var == 0 && nameref == 0 && unset_variable == 0 && unset_function == 0)
+ {
+ if (var = find_function (name))
+ unset_function = 1;
+ }
+
+ /* Posix.2 says that unsetting readonly variables is an error. */
+ if (var && readonly_p (var))
+ {
+ builtin_error (_("%s: cannot unset: readonly %s"),
+ var->name, unset_function ? "function" : "variable");
+ NEXT_VARIABLE ();
+ }
+
+ /* Unless the -f option is supplied, the name refers to a variable. */
+#if defined (ARRAY_VARS)
+ if (var && unset_array)
+ {
+ /* Let unbind_array_element decide what to do with non-array vars */
+ tem = unbind_array_element (var, t, vflags); /* XXX new third arg */
+ if (tem == -2 && array_p (var) == 0 && assoc_p (var) == 0)
+ {
+ builtin_error (_("%s: not an array variable"), var->name);
+ NEXT_VARIABLE ();
+ }
+ else if (tem < 0)
+ any_failed++;
+ }
+ else
+#endif /* ARRAY_VARS */
+ /* If we're trying to unset a nameref variable whose value isn't a set
+ variable, make sure we still try to unset the nameref's value */
+ if (var == 0 && nameref == 0 && unset_function == 0)
+ {
+ var = find_variable_last_nameref (name, 0);
+ if (var && nameref_p (var))
+ {
+#if defined (ARRAY_VARS)
+ if (valid_array_reference (nameref_cell (var), 0))
+ {
+ tname = savestring (nameref_cell (var));
+ if (var = array_variable_part (tname, 0, &t, (int *)0))
+ tem = unbind_array_element (var, t, vflags); /* XXX new third arg */
+ free (tname);
+ }
+ else
+#endif
+ tem = unbind_variable (nameref_cell (var));
+ }
+ else
+ tem = unbind_variable (name);
+ }
+ else
+ tem = unset_function ? unbind_func (name) : (nameref ? unbind_nameref (name) : unbind_variable (name));
+
+ /* This is what Posix.2 says: ``If neither -f nor -v
+ is specified, the name refers to a variable; if a variable by
+ that name does not exist, a function by that name, if any,
+ shall be unset.'' */
+ if (tem == -1 && nameref == 0 && unset_function == 0 && unset_variable == 0)
+ tem = unbind_func (name);
+
+ name = list->word->word; /* reset above for namerefs */
+
+ /* SUSv3, POSIX.1-2001 say: ``Unsetting a variable or function that
+ was not previously set shall not be considered an error.'' */
+
+ if (unset_function == 0)
+ stupidly_hack_special_variables (name);
+
+ list = list->next;
+ }
+
+ return (any_failed ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
+}