add restricted mode, per IO ERROR's patch

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@1723 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

ChangeLog

@@ -9,14 +9,42 @@ CVS code -
 	- Add better explanations for and in the "Terminal breakage"
 	  comments, and handle missing key #ifdefs inside the functions
 	  that use those keys. (DLR)
+	- Add restricted mode, accessible via the -Z/--restricted
+	  command line option or by invoking nano with any name
+	  beginning with 'r' (e.g. "rnano").  In restricted mode, nano
+	  will not read or write to any file not specified on the
+	  command line, read any nanorc files, allow suspending, or
+	  allow a file to be appended to, prepended to, or saved under a
+	  different name if it already has one. (IO ERROR)  DLR: Also
+	  disable backup files and spell checking (since the latter can
+	  leave a pre-spell-checked version of the file in a temporary
+	  directory), use tail() to get the program name so that the
+	  check for its beginning with 'r' will work when a path is
+	  specified, disable toggles that are only useful with options
+	  that are disabled in restricted mode, call nano_disabled_msg()
+	  when trying to read or spell check a file instead of leaving
+	  the shortcuts out of the main list, and instead of acting as
+	  though TEMP_OPT is enabled when exiting with a modified file
+	  (which caused problems if the filename was blank), only allow
+	  a filename to be modified at the writeout prompt if it's blank
+	  beforehand.  Changes to do_writeout(), toggle_init(),
+	  shortcut_init(), die_save_file(), and nanogetstr().
+	- Call nano_disabled_msg() directly from the shortcut list
+	  instead of inside the disabled functions. (David Benbennick)
 - files.c:
   add_open_file()
 	- Rearrange the NANO_SMALL #ifdef so that the code to set the
 	  MODIFIED flag in open_files->flags is included only once.
 	  (DLR)
+  do_writeout()
+	- Refactor so that no recursion is needed if we try to exit with
+	  a modified file that has no name when TEMP_OPT is set. (DLR)
 - nano.c:
   do_delete()
 	- Tweak for efficiency. (David Benbennick)
+  do_exit()
+	- Refactor so that no recursion is needed if we try to exit with
+	  a modified file that has no name when TEMP_OPT is set. (DLR)
   print_numlock_warning()
 	- Removed, as it's no longer needed and was never called
 	  anywhere after the input overhaul. (DLR)
@@ -72,9 +100,14 @@ CVS code -
 	- Use napms() instead of nanosleep(), as it does the same thing
 	  (aside from taking an argument in milliseconds instead of
 	  microseconds) and curses includes it. (DLR)
+- nano.1:
+	- Document restricted mode. (IO ERROR)  DLR: Add minor
+	  modifications to account for the above changes.
 - nano.texi:
 	- Fix inaccuracies: Meta-L now toggles line wrapping, and Meta-<
 	  and Meta-> aren't toggles. (DLR)
+	- Document restricted mode. (IO ERROR)  DLR: Add minor
+	  modifications to account for the above changes.
 - faq.html:
 	- Removed question about the NumLock glitch, as it's no longer
 	  needed. (DLR)

doc/man/nano.1

@@ -92,6 +92,13 @@ Specify a specific syntax highlighting from the
 .I .nanorc
 to use, if available.
 .TP
+.B \-Z (\-\-restricted)
+Restricted mode: Don't read or write to any file not specified on the
+command line, read any nanorc files, allow suspending, or allow a file
+to be appended to, prepended to, or saved under a different name if it
+already has one.  Also accessible by invoking \fBnano\fP with any name
+beginning with 'r' (e.g. "rnano").
+.TP
 .B \-c (\-\-const)
 Constantly show the cursor position.
 .TP

doc/texinfo/nano.texi

@@ -157,6 +157,13 @@ Print the version number and copyright and quit.
 Specify a specific syntax highlighting from the .nanorc to use, if
 available.
 
+@item -Z, --restricted
+Restricted mode: Don't read or write to any file not specified on the
+command line, read any nanorc files, allow suspending, or allow a file
+to be appended to, prepended to, or saved under a different name if it
+already has one.  Also accessible by invoking @code{nano} with any name
+beginning with 'r' (e.g. "rnano").
+
 @item -c, --const
 Constantly display the cursor position and line number on the statusbar.
 

src/files.c

@@ -1808,9 +1808,7 @@ int do_writeout(int exiting)
     currshortcut = writefile_list;
 #endif
 
-    if (exiting && ISSET(TEMP_OPT)) {
-	i = -1;
-	if (filename[0] != '\0') {
+    if (exiting && filename[0] != '\0' && ISSET(TEMP_OPT)) {
 	i = write_file(filename, FALSE, 0, FALSE);
 	if (i == 1) {
 	    /* Write succeeded. */
@@ -1819,16 +1817,6 @@ int do_writeout(int exiting)
 	}
     }
 
-	/* No filename or the write above failed. */
-	if (i == -1) {
-	    UNSET(TEMP_OPT);
-	    do_exit();
-
-	    /* They cancelled; abort quit. */
-	    return -1;
-	}
-    }
-
 #ifndef NANO_SMALL
     if (ISSET(MARK_ISSET) && !exiting)
 	answer = mallocstrcpy(answer, "");
@@ -1941,9 +1929,9 @@ int do_writeout(int exiting)
 		i = do_yesno(FALSE, _("File exists, OVERWRITE ?"));
 		if (i == 0 || i == -1)
 		    continue;
-	    } else if (filename[0] != '\0'
+	    } else if (!ISSET(RESTRICTED) && filename[0] != '\0'
 #ifndef NANO_SMALL
-		&& (!ISSET(MARK_ISSET) || exiting)
+		&& (exiting || !ISSET(MARK_ISSET))
 #endif
 		) {
 		i = do_yesno(FALSE, _("Save file under DIFFERENT NAME ?"));
@@ -1955,7 +1943,7 @@ int do_writeout(int exiting)
 #ifndef NANO_SMALL
 	/* Here's where we allow the selected text to be written to
 	 * a separate file. */
-	if (ISSET(MARK_ISSET) && !exiting)
+	if (!ISSET(RESTRICTED) && !exiting && ISSET(MARK_ISSET))
 	    i = write_marked(answer, FALSE, append, FALSE);
 	else
 #endif /* !NANO_SMALL */
@@ -2432,7 +2420,6 @@ char *input_tab(char *buf, int place, int *lastwastab, int *newplace, int *list)
 }
 #endif /* !DISABLE_TABCOMP */
 
-#if !defined(DISABLE_BROWSER) || !defined(NANO_SMALL)
 /* Only print the last part of a path; isn't there a shell
  * command for this? */
 const char *tail(const char *foo)
@@ -2447,7 +2434,6 @@ const char *tail(const char *foo)
 
     return tmp;
 }
-#endif
 
 #ifndef DISABLE_BROWSER
 /* Our sort routine for file listings -- sort directories before

src/global.c

@@ -275,6 +275,7 @@ void toggle_init(void)
 
     toggle_init_one(TOGGLE_NOHELP_KEY, toggle_nohelp_msg, NO_HELP);
 #ifdef ENABLE_MULTIBUFFER
+    if (!ISSET(RESTRICTED))
 	toggle_init_one(TOGGLE_MULTIBUFFER_KEY, toggle_multibuffer_msg, MULTIBUFFER);
 #endif
     toggle_init_one(TOGGLE_CONST_KEY, toggle_const_msg, CONSTUPDATE);
@@ -283,14 +284,17 @@ void toggle_init(void)
     toggle_init_one(TOGGLE_WRAP_KEY, toggle_wrap_msg, NO_WRAP);
 #endif
     toggle_init_one(TOGGLE_CUTTOEND_KEY, toggle_cuttoend_msg, CUT_TO_END);
+    if (!ISSET(RESTRICTED))
 	toggle_init_one(TOGGLE_SUSPEND_KEY, toggle_suspend_msg, SUSPEND);
 #ifndef DISABLE_MOUSE
     toggle_init_one(TOGGLE_MOUSE_KEY, toggle_mouse_msg, USE_MOUSE);
 #endif
+    if (!ISSET(RESTRICTED)) {
 	toggle_init_one(TOGGLE_NOCONVERT_KEY, toggle_noconvert_msg, NO_CONVERT);
 	toggle_init_one(TOGGLE_DOS_KEY, toggle_dos_msg, DOS_FILE);
 	toggle_init_one(TOGGLE_MAC_KEY, toggle_mac_msg, MAC_FILE);
 	toggle_init_one(TOGGLE_BACKUP_KEY, toggle_backup_msg, BACKUP_FILE);
+    }
     toggle_init_one(TOGGLE_SMOOTH_KEY, toggle_smooth_msg, SMOOTHSCROLL);
 #ifdef ENABLE_COLOR
     toggle_init_one(TOGGLE_SYNTAX_KEY, toggle_syntax_msg, COLOR_SYNTAX);
@@ -437,7 +441,13 @@ void shortcut_init(int unjustify)
     /* Translators: try to keep this string under 10 characters long */
     sc_init_one(&main_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
 #ifdef ENABLE_MULTIBUFFER
     if (open_files != NULL && (open_files->prev != NULL || open_files->next != NULL))
@@ -461,7 +471,13 @@ void shortcut_init(int unjustify)
     /* Translators: try to keep this string under 10 characters long */
     sc_init_one(&main_list, NANO_JUSTIFY_KEY, _("Justify"),
 		IFHELP(nano_justify_msg, NANO_NO_KEY),
-		NANO_JUSTIFY_FKEY, NANO_NO_KEY, NOVIEW, do_justify);
+		NANO_JUSTIFY_FKEY, NANO_NO_KEY, NOVIEW,
+#ifndef NANO_SMALL
+		do_justify
+#else
+		nano_disabled_msg
+#endif
+		);
 
     /* this is so we can view multiple files */
     /* Translators: try to keep this string under 10 characters long */
@@ -473,7 +489,7 @@ void shortcut_init(int unjustify)
 #else
 		NOVIEW
 #endif
-		, do_insertfile_void);
+		, !ISSET(RESTRICTED) ? do_insertfile_void : nano_disabled_msg);
 
     /* Translators: try to keep this string under 10 characters long */
     sc_init_one(&main_list, NANO_WHEREIS_KEY, _("Where Is"),
@@ -514,7 +530,11 @@ void shortcut_init(int unjustify)
     /* Translators: try to keep this string under 10 characters long */
     sc_init_one(&main_list, NANO_SPELL_KEY, _("To Spell"),
 		IFHELP(nano_spell_msg, NANO_NO_KEY), NANO_SPELL_FKEY,
-		NANO_NO_KEY, NOVIEW, do_spell);
+		NANO_NO_KEY, NOVIEW,
+#ifndef DISABLE_SPELLER
+		!ISSET(RESTRICTED) ? do_spell :
+#endif
+		nano_disabled_msg);
 
     sc_init_one(&main_list, NANO_GOTO_KEY, _("Go To Line"),
 		IFHELP(nano_goto_msg, NANO_ALT_GOTO_KEY), NANO_GOTO_FKEY,
@@ -554,7 +574,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&main_list, NANO_MARK_KEY, _("Mark Text"),
 		IFHELP(nano_mark_msg, NANO_ALT_MARK_KEY),
-		NANO_NO_KEY, NANO_NO_KEY, NOVIEW, do_mark);
+		NANO_NO_KEY, NANO_NO_KEY, NOVIEW,
+#ifndef NANO_SMALL
+		do_mark
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&main_list, NANO_DELETE_KEY, _("Delete"),
 		IFHELP(nano_delete_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -610,7 +636,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&whereis_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     /* Translators: try to keep this string under 10 characters long */
     sc_init_one(&whereis_list, NANO_CANCEL_KEY, _("Cancel"),
@@ -680,7 +712,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&replace_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&replace_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -727,7 +765,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&replace_list_2, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&replace_list_2, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -751,7 +795,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&goto_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&goto_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -785,10 +835,17 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&writefile_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
 #ifndef DISABLE_BROWSER
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_TOFILES_KEY, _("To Files"),
 		IFHELP(nano_tofiles_msg, NANO_NO_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
@@ -796,28 +853,33 @@ void shortcut_init(int unjustify)
 
 #ifndef NANO_SMALL
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_NO_KEY, _("DOS Format"),
 		IFHELP(nano_dos_msg, TOGGLE_DOS_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
 
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_NO_KEY, _("Mac Format"),
 		IFHELP(nano_mac_msg, TOGGLE_MAC_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
 #endif
 
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_NO_KEY, _("Append"),
 		IFHELP(nano_append_msg, NANO_APPEND_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
 
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_NO_KEY, _("Prepend"),
 		IFHELP(nano_prepend_msg, NANO_PREPEND_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
 
 #ifndef NANO_SMALL
     /* Translators: try to keep this string under 16 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&writefile_list, NANO_NO_KEY, _("Backup File"),
 		IFHELP(nano_backup_msg, TOGGLE_BACKUP_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
@@ -831,13 +893,20 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&insertfile_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&insertfile_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, VIEW, 0);
 
 #ifndef DISABLE_BROWSER
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&insertfile_list, NANO_TOFILES_KEY, _("To Files"),
 		IFHELP(nano_tofiles_msg, NANO_NO_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
@@ -845,12 +914,14 @@ void shortcut_init(int unjustify)
 
 #ifndef NANO_SMALL
     /* Translators: try to keep this string under 22 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&insertfile_list, NANO_EXTCMD_KEY, _("Execute Command"),
 		IFHELP(nano_execute_msg, NANO_NO_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
 
 #ifdef ENABLE_MULTIBUFFER
     /* Translators: try to keep this string under 22 characters long */
+    if (!ISSET(RESTRICTED))
 	sc_init_one(&insertfile_list, NANO_NO_KEY, _("New Buffer"),
 		IFHELP(nano_multibuffer_msg, TOGGLE_MULTIBUFFER_KEY), NANO_NO_KEY,
 		NANO_NO_KEY, NOVIEW, 0);
@@ -862,7 +933,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&spell_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&spell_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -874,7 +951,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&extcmd_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&extcmd_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -886,7 +969,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&browser_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&browser_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,
@@ -909,7 +998,13 @@ void shortcut_init(int unjustify)
 
     sc_init_one(&gotodir_list, NANO_HELP_KEY, _("Get Help"),
 		IFHELP(nano_help_msg, NANO_NO_KEY), NANO_HELP_FKEY,
-		NANO_NO_KEY, VIEW, do_help);
+		NANO_NO_KEY, VIEW,
+#ifndef DISABLE_HELP
+		do_help
+#else
+		nano_disabled_msg
+#endif
+		);
 
     sc_init_one(&gotodir_list, NANO_CANCEL_KEY, _("Cancel"),
 		IFHELP(nano_cancel_msg, NANO_NO_KEY), NANO_NO_KEY,

src/nano.c

@@ -151,6 +151,10 @@ void die_save_file(const char *die_filename)
     char *ret;
     int i = -1;
 
+    /* No emergency files in restricted mode! */
+    if (ISSET(RESTRICTED))
+	return;
+
     /* If we can't save, we have REAL bad problems, but we might as well
        TRY. */
     if (die_filename[0] == '\0')
@@ -656,6 +660,7 @@ void usage(void)
 #ifdef ENABLE_COLOR
     print1opt(_("-Y [str]"), _("--syntax [str]"), _("Syntax definition to use"));
 #endif
+    print1opt(_("-Z"), _("--restricted"), _("Restricted mode"));
     print1opt("-c", "--const", _("Constantly show cursor position"));
 #ifndef NANO_SMALL
     print1opt("-d", "--rebinddelete", _("Fix Backspace/Delete confusion problem"));
@@ -765,12 +770,11 @@ int no_help(void)
     return ISSET(NO_HELP) ? 2 : 0;
 }
 
-#if defined(DISABLE_JUSTIFY) || defined(DISABLE_SPELLER) || defined(DISABLE_HELP) || defined(NANO_SMALL)
-void nano_disabled_msg(void)
+int nano_disabled_msg(void)
 {
     statusbar(_("Sorry, support for this function has been disabled"));
+    return 1;
 }
-#endif
 
 #ifndef NANO_SMALL
 static int pid;		/* This is the PID of the newly forked process
@@ -1231,13 +1235,9 @@ int do_prev_word(void)
 
     return 0;
 }
-#endif /* !NANO_SMALL */
 
 int do_mark(void)
 {
-#ifdef NANO_SMALL
-    nano_disabled_msg();
-#else
     TOGGLE(MARK_ISSET);
     if (ISSET(MARK_ISSET)) {
 	statusbar(_("Mark Set"));
@@ -1247,9 +1247,9 @@ int do_mark(void)
 	statusbar(_("Mark UNset"));
 	edit_refresh();
     }
-#endif
     return 1;
 }
+#endif /* !NANO_SMALL */
 
 #ifndef DISABLE_WRAPPING
 void wrap_reset(void)
@@ -1829,14 +1829,9 @@ char *do_alt_speller(char *tempfile_name)
 
     return NULL;
 }
-#endif
 
 int do_spell(void)
 {
-#ifdef DISABLE_SPELLER
-    nano_disabled_msg();
-    return 1;
-#else
     int i;
     char *temp, *spell_msg;
 
@@ -1879,8 +1874,8 @@ int do_spell(void)
 
     statusbar(_("Finished checking spelling"));
     return 1;
-#endif
 }
+#endif /* !DISABLE_SPELLER */
 
 #if !defined(NANO_SMALL) || !defined(DISABLE_JUSTIFY)
 /* The "indentation" of a line is the white-space between the quote part
@@ -2404,15 +2399,10 @@ int do_para_end(void)
 {
     return do_para_search(2, NULL, NULL, NULL, TRUE);
 }
-#endif
 
 /* Justify a paragraph. */
 int do_justify(void)
 {
-#ifdef DISABLE_JUSTIFY
-    nano_disabled_msg();
-    return 1;
-#else
     size_t quote_len;
 	/* Length of the initial quotation of the paragraph we
 	 * justify. */
@@ -2706,8 +2696,8 @@ int do_justify(void)
     display_main_list();
 
     return 0;
-#endif /* !DISABLE_JUSTIFY */
 }
+#endif /* !DISABLE_JUSTIFY */
 
 int do_exit(void)
 {
@@ -3088,6 +3078,7 @@ int main(int argc, char *argv[])
 	{"mac", 0, 0, 'M'},
 	{"noconvert", 0, 0, 'N'},
 	{"smooth", 0, 0, 'S'},
+	{"restricted", 0, 0, 'Z'},
 	{"autoindent", 0, 0, 'i'},
 	{"cut", 0, 0, 'k'},
 #endif
@@ -3109,11 +3100,11 @@ int main(int argc, char *argv[])
 #endif
 
 #ifdef HAVE_GETOPT_LONG
-    while ((optchr = getopt_long(argc, argv, "h?BDE:FHIMNQ:RST:VY:abcdefgijklmo:pr:s:tvwxz",
+    while ((optchr = getopt_long(argc, argv, "h?BDE:FHIMNQ:RST:VY:Zabcdefgijklmo:pr:s:tvwxz",
 				 long_options, NULL)) != -1) {
 #else
     while ((optchr =
-	    getopt(argc, argv, "h?BDE:FHIMNQ:RST:VY:abcdefgijklmo:pr:s:tvwxz")) != -1) {
+	    getopt(argc, argv, "h?BDE:FHIMNQ:RST:VY:Zabcdefgijklmo:pr:s:tvwxz")) != -1) {
 #endif
 
 	switch (optchr) {
@@ -3201,6 +3192,9 @@ int main(int argc, char *argv[])
 	    syntaxstr = mallocstrcpy(syntaxstr, optarg);
 	    break;
 #endif
+	case 'Z':
+	    SET(RESTRICTED);
+	    break;
 	case 'c':
 	    SET(CONSTUPDATE);
 	    break;
@@ -3275,6 +3269,18 @@ int main(int argc, char *argv[])
 	}
     }
 
+    /* If filename starts with 'r', we use restricted mode. */
+    if (*(tail(argv[0])) == 'r')
+	SET(RESTRICTED);
+
+    /* If we're using restricted mode, disable suspending, backup files,
+     * and reading rcfiles. */
+    if (ISSET(RESTRICTED)) {
+	UNSET(SUSPEND);
+	UNSET(BACKUP_FILE);
+	SET(NO_RCFILE);
+    }
+
 /* We've read through the command line options.  Now back up the flags
    and values that are set, and read the rcfile(s).  If the values
    haven't changed afterward, restore the backed-up values. */

src/nano.h

@@ -268,6 +268,7 @@ typedef struct historyheadtype {
 #define PRESERVE		(1<<27)
 #define HISTORY_CHANGED		(1<<28)
 #define HISTORYLOG		(1<<29)
+#define RESTRICTED		(1<<30)
 
 /* Control key sequences, changing these would be very very bad. */
 #define NANO_CONTROL_SPACE 0

src/proto.h

@@ -199,9 +199,7 @@ char **username_tab_completion(char *buf, int *num_matches);
 char **cwd_tab_completion(char *buf, int *num_matches);
 char *input_tab(char *buf, int place, int *lastwastab, int *newplace, int *list);
 #endif
-#if !defined(DISABLE_BROWSER) || !defined(NANO_SMALL)
 const char *tail(const char *foo);
-#endif
 #ifndef DISABLE_BROWSER
 int diralphasort(const void *va, const void *vb);
 void free_charptrarray(char **array, int len);
@@ -272,9 +270,7 @@ void usage(void);
 void version(void);
 void do_early_abort(void);
 int no_help(void);
-#if defined(DISABLE_JUSTIFY) || defined(DISABLE_SPELLER) || defined(DISABLE_HELP) || defined(NANO_SMALL)
-void nano_disabled_msg(void);
-#endif
+int nano_disabled_msg(void);
 #ifndef NANO_SMALL
 RETSIGTYPE cancel_fork(int signal);
 int open_pipe(const char *command);
@@ -291,8 +287,8 @@ int do_enter(void);
 #ifndef NANO_SMALL
 int do_next_word(void);
 int do_prev_word(void);
-#endif
 int do_mark(void);
+#endif
 #ifndef DISABLE_WRAPPING
 void wrap_reset(void);
 int do_wrap(filestruct *inptr);
@@ -301,8 +297,8 @@ int do_wrap(filestruct *inptr);
 int do_int_spell_fix(const char *word);
 char *do_int_speller(char *tempfile_name);
 char *do_alt_speller(char *tempfile_name);
-#endif
 int do_spell(void);
+#endif
 #if !defined(DISABLE_WRAPPING) && !defined(NANO_SMALL) || !defined(DISABLE_JUSTIFY)
 size_t indent_length(const char *line);
 #endif
@@ -330,8 +326,8 @@ int do_para_search(int search_type, size_t *quote, size_t *par, size_t
 	*indent, int do_refresh);
 int do_para_begin(void);
 int do_para_end(void);
-#endif /* !DISABLE_JUSTIFY */
 int do_justify(void);
+#endif /* !DISABLE_JUSTIFY */
 int do_exit(void);
 void signal_init(void);
 RETSIGTYPE handle_hupterm(int signal);

src/winio.c

@@ -1311,23 +1311,29 @@ int nanogetstr(int allowtabs, const char *buf, const char *def,
 		x++;
 	    break;
 	case NANO_DELETE_KEY:
+	    if (!ISSET(RESTRICTED) || filename[0] == '\0' || s != writefile_list) {
 		if (x < xend) {
 		    charmove(answer + x, answer + x + 1, xend - x);
 		    xend--;
 		}
+	    }
 	    break;
 	case NANO_CUT_KEY:
 	case NANO_UNCUT_KEY:
+	    if (!ISSET(RESTRICTED) || filename[0] == '\0' || s != writefile_list) {
 		null_at(&answer, 0);
 		xend = 0;
 		x = 0;
+	    }
 	    break;
 	case NANO_BACKSPACE_KEY:
+	    if (!ISSET(RESTRICTED) || filename[0] == '\0' || s != writefile_list) {
 		if (x > 0) {
 		    charmove(answer + x - 1, answer + x, xend - x + 1);
 		    x--;
 		    xend--;
 		}
+	    }
 	    break;
 	case NANO_TAB_KEY:
 #ifndef NANO_SMALL
@@ -1465,7 +1471,7 @@ int nanogetstr(int allowtabs, const char *buf, const char *def,
 			return kbinput;
 		}
 
-	    if (is_cntrl_char(kbinput))
+	    if (is_cntrl_char(kbinput) || (ISSET(RESTRICTED) && filename[0] != '\0' && s == writefile_list))
 		break;
 	    answer = charealloc(answer, xend + 2);
 	    charmove(answer + x + 1, answer + x, xend - x + 1);
@@ -2471,11 +2477,11 @@ int line_len(const char *ptr)
     return j;
 }
 
+#ifndef DISABLE_HELP
 /* Our shortcut-list-compliant help function, which is better than
  * nothing, and dynamic! */
 int do_help(void)
 {
-#ifndef DISABLE_HELP
     int i, page = 0, kbinput = ERR, meta_key, no_more = 0;
     int no_help_flag = 0;
     const shortcut *oldshortcut;
@@ -2572,12 +2578,9 @@ int do_help(void)
     free(help_text);
     help_text = NULL;
 
-#elif defined(DISABLE_HELP)
-    nano_disabled_msg();
-#endif
-
     return 1;
 }
+#endif /* !DISABLE_HELP */
 
 /* Highlight the current word being replaced or spell checked.  We
  * expect word to have tabs and control characters expanded. */