Add CLI options for individual -r features and to counter previous options

The --enable-* options also work for imported files, this fixes #120.

Most other options are not super useful on its own, but these will be
useful when there's a config file.

ncdu.pod

@@ -57,12 +57,12 @@ directory with many files. 10.000 files will get you an export in the order of
 gzip. This scales linearly, so be prepared to handle a few tens of megabytes
 when dealing with millions of files.
 
-=item -e
+=item -e, --extended, --no-extended
 
-Enable extended information mode. This will, in addition to the usual file
+Enable/disable extended information mode. This will, in addition to the usual
-information, also read the ownership, permissions and last modification time
+file information, also read the ownership, permissions and last modification
-for each file. This will result in higher memory usage (by roughly ~30%) and in
+time for each file. This will result in higher memory usage (by roughly ~30%)
-a larger output file when exporting.
+and in a larger output file when exporting.
 
 When using the file export/import function, this flag will need to be added
 both when exporting (to make sure the information is added to the export), and
@@ -102,40 +102,48 @@ Provide a full-screen ncurses interface while scanning a directory or importing
 a file. This is the only interface that provides feedback on any non-fatal
 errors while scanning.
 
-=item -q
+=item -q, --slow-ui-updates, --fast-ui-updates
 
-Quiet mode. While scanning or importing the directory, ncdu will update the
+Change the UI update interval while scanning or importing. Ncdu will update the
-screen 10 times a second by default, this will be decreased to once every 2
+screen 10 times a second by default (C<--fast-ui-updates>), this can be
-seconds in quiet mode. Use this feature to save bandwidth over remote
+decreased to once every 2 seconds with C<-q> or C<--slow-ui-updates>. This
-connections. This option has no effect when C<-0> is used.
+feature can be used to save bandwidth over remote connections. This option has
+no effect when C<-0> is used.
+
+=item --enable-shell, --disable-shell
+
+Enable or disable shell spawning from the browser. This feature is enabled by
+default when scanning a live directory and disabled when importing from file.
+
+=item --enable-delete, --disable-delete
+
+Enable or disable the built-in file deletion feature. This feature is enabled
+by default when scanning a live directory and disabled when importing from
+file. Explicitly disabling the deletion feature can work as a safeguard to
+prevent accidental data loss.
+
+=item --enable-refresh, --disable-refresh
+
+Enable or disable directory refreshing from the browser. This feature is
+enabled by default when scanning a live directory and disabled when importing
+from file.
 
 =item -r
 
-Read-only mode. This will disable the built-in file deletion feature. This
+Read-only mode. When given once, this is an alias for C<--disable-delete>, when
-option has no effect when C<-o> is used, because there will not be a browser
+given twice it will also add C<--disable-shell>, thus ensuring that there is no
-interface in that case. It has no effect when C<-f> is used, either, because
+way to modify the file system from within ncdu.
-the deletion feature is disabled in that case anyway.
 
-WARNING: This option will only prevent deletion through the file browser. It is
+=item --si, --no-si
-still possible to spawn a shell from ncdu and delete or modify files from
-there. To disable that feature as well, pass the C<-r> option twice (see
-C<-rr>).
-
-=item -rr
-
-In addition to C<-r>, this will also disable the shell spawning feature of the
-file browser.
-
-=item --si
 
 List sizes using base 10 prefixes, that is, powers of 1000 (KB, MB, etc), as
 defined in the International System of Units (SI), instead of the usual base 2
 prefixes, that is, powers of 1024 (KiB, MiB, etc).
 
-=item --confirm-quit
+=item --confirm-quit, --no-confirm-quit
 
-Requires a confirmation before quitting ncdu. Very helpful when you
+Require a confirmation before quitting ncdu. Very helpful when you accidentally
-accidentally press 'q' during or after a very long scan.
+press 'q' during or after a very long scan.
 
 =item --color I<SCHEME>
 
@@ -155,11 +163,16 @@ directory information from a file.
 
 =over
 
-=item -x
+=item -x, --one-file-system
 
 Do not cross filesystem boundaries, i.e. only count files and directories on
 the same filesystem as the directory being scanned.
 
+=item --cross-file-system
+
+Do cross filesystem boundaries. This is the default, but can be specified to
+overrule a previously given C<-x>.
+
 =item --exclude I<PATTERN>
 
 Exclude files that match I<PATTERN>. The files will still be displayed by
@@ -171,27 +184,24 @@ can be added multiple times to add more patterns.
 Exclude files that match any pattern in I<FILE>. Patterns should be separated
 by a newline.
 
-=item --exclude-caches
+=item --include-caches, --exclude-caches
 
-Exclude directories containing CACHEDIR.TAG.  The directories will still be
+Include (default) or exclude directories containing CACHEDIR.TAG.  The
-displayed, but not their content, and they are not counted towards the disk
+directories will still be displayed, but their contents will not be scanned or
-usage statistics.
+counted towards the disk usage statistics.
-See http://www.brynosaurus.com/cachedir/
+L<http://www.brynosaurus.com/cachedir/>
 
-=item -L, --follow-symlinks
+=item -L, --follow-symlinks, --no-follow-symlinks
 
-Follow symlinks and count the size of the file they point to. As of ncdu 1.14,
+Follow (or not) symlinks and count the size of the file they point to. As of
-this option will not follow symlinks to directories and will count each
+ncdu 1.14, this option will not follow symlinks to directories and will count
-symlinked file as a unique file (i.e. unlike how hard links are handled). This
+each symlinked file as a unique file (i.e. unlike how hard links are handled).
-is subject to change in later versions.
+This is subject to change in later versions.
 
-=item --exclude-firmlinks
+=item --include-kernfs, --exclude-kernfs
 
-(MacOS only) Exclude firmlinks.
+(Linux only) Include (default) or exclude Linux pseudo filesystems, e.g. /proc
-
+(procfs), /sys (sysfs).
-=item --exclude-kernfs
-
-(Linux only) Exclude Linux pseudo filesystems, e.g. /proc (procfs), /sys (sysfs).
 
 The complete list of currently known pseudo filesystems is: binfmt, bpf, cgroup,
 cgroup2, debug, devpts, proc, pstore, security, selinux, sys, trace.

src/browser.zig

@@ -729,7 +729,7 @@ pub fn draw() void {
     if (main.config.imported) {
         ui.move(0, saturateSub(ui.cols, 10));
         ui.addstr("[imported]");
-    } else if (main.config.read_only) {
+    } else if (!main.config.can_delete) {
         ui.move(0, saturateSub(ui.cols, 10));
         ui.addstr("[readonly]");
     }
@@ -840,27 +840,23 @@ pub fn keyInput(ch: i32) void {
         '?' => state = .help,
         'i' => if (dir_items.items.len > 0) info.set(dir_items.items[cursor_idx], .info),
         'r' => {
-            if (main.config.imported)
+            if (!main.config.can_refresh)
-                message = "Directory imported from file, refreshing is disabled."
+                message = "Directory refresh feature disabled."
             else {
                 main.state = .refresh;
                 scan.setupRefresh(dir_parent);
             }
         },
         'b' => {
-            if (main.config.imported)
+            if (!main.config.can_shell)
-                message = "Shell feature not available for imported directories."
+                message = "Shell feature disabled."
-            else if (!main.config.can_shell)
-                message = "Shell feature disabled in read-only mode."
             else
                 main.state = .shell;
         },
         'd' => {
             if (dir_items.items.len == 0) {
-            } else if (main.config.imported)
+            } else if (!main.config.can_delete)
-                message = "Deletion feature not available for imported directories."
+                message = "Deletion feature disabled."
-            else if (main.config.read_only)
-                message = "Deletion feature disabled in read-only mode."
             else if (dir_items.items[cursor_idx]) |e| {
                 main.state = .delete;
                 const next =

src/main.zig

@@ -65,9 +65,10 @@ pub const config = struct {
     pub var sort_order: SortOrder = .desc;
     pub var sort_dirsfirst: bool = false;
 
-    pub var read_only: bool = false;
     pub var imported: bool = false;
+    pub var can_delete: bool = true;
     pub var can_shell: bool = true;
+    pub var can_refresh: bool = true;
     pub var confirm_quit: bool = false;
     pub var confirm_delete: bool = true;
     pub var ignore_delete_errors: bool = false;
@@ -266,6 +267,9 @@ pub fn main() void {
     var import_file: ?[:0]const u8 = null;
     var export_file: ?[:0]const u8 = null;
     var has_scan_ui = false;
+    var has_can_delete = false;
+    var has_can_shell = false;
+    var has_can_refresh = false;
     _ = args.next(); // program name
     while (args.next()) |opt| {
         if (!opt.opt) {
@@ -276,11 +280,20 @@ pub fn main() void {
         }
         if (opt.is("-h") or opt.is("-?") or opt.is("--help")) help()
         else if(opt.is("-v") or opt.is("-V") or opt.is("--version")) version()
-        else if(opt.is("-q")) config.update_delay = 2*std.time.ns_per_s
+        else if(opt.is("-q") or opt.is("--slow-ui-updates")) config.update_delay = 2*std.time.ns_per_s
-        else if(opt.is("-x")) config.same_fs = true
+        else if(opt.is("--fast-ui-updates")) config.update_delay = 100*std.time.ns_per_ms
-        else if(opt.is("-e")) config.extended = true
+        else if(opt.is("-x") or opt.is("--one-file-system")) config.same_fs = true
-        else if(opt.is("-r") and config.read_only) config.can_shell = false
+        else if(opt.is("--cross-file-system")) config.same_fs = false
-        else if(opt.is("-r")) config.read_only = true
+        else if(opt.is("-e") or opt.is("--extended")) config.extended = true
+        else if(opt.is("--no-extended")) config.extended = false
+        else if(opt.is("-r") and !config.can_delete) config.can_shell = false
+        else if(opt.is("-r")) config.can_delete = false
+        else if(opt.is("--enable-shell"))    { has_can_shell = true;   config.can_shell = true; }
+        else if(opt.is("--disable-shell"))   { has_can_shell = true;   config.can_shell = false; }
+        else if(opt.is("--enable-delete"))   { has_can_delete = true;  config.can_delete = true; }
+        else if(opt.is("--disable-delete"))  { has_can_delete = true;  config.can_delete = false; }
+        else if(opt.is("--enable-refresh"))  { has_can_refresh = true; config.can_refresh = true; }
+        else if(opt.is("--disable-refresh")) { has_can_refresh = true; config.can_refresh = false; }
         else if(opt.is("-0")) { has_scan_ui = true; config.scan_ui = .none; }
         else if(opt.is("-1")) { has_scan_ui = true; config.scan_ui = .line; }
         else if(opt.is("-2")) { has_scan_ui = true; config.scan_ui = .full; }
@@ -289,14 +302,19 @@ pub fn main() void {
         else if(opt.is("-f") and import_file != null) ui.die("The -f flag can only be given once.\n", .{})
         else if(opt.is("-f")) import_file = args.arg()
         else if(opt.is("--si")) config.si = true
+        else if(opt.is("--no-si")) config.si = false
         else if(opt.is("-L") or opt.is("--follow-symlinks")) config.follow_symlinks = true
+        else if(opt.is("--no-follow-symlinks")) config.follow_symlinks = false
         else if(opt.is("--exclude")) config.exclude_patterns.append(args.arg()) catch unreachable
         else if(opt.is("-X") or opt.is("--exclude-from")) {
             const arg = args.arg();
             readExcludeFile(arg) catch |e| ui.die("Error reading excludes from {s}: {s}.\n", .{ arg, ui.errorString(e) });
         } else if(opt.is("--exclude-caches")) config.exclude_caches = true
+        else if(opt.is("--include-caches")) config.exclude_caches = false
         else if(opt.is("--exclude-kernfs")) config.exclude_kernfs = true
+        else if(opt.is("--include-kernfs")) config.exclude_kernfs = false
         else if(opt.is("--confirm-quit")) config.confirm_quit = true
+        else if(opt.is("--no-confirm-quit")) config.confirm_quit = false
         else if(opt.is("--color")) {
             const val = args.arg();
             if (std.mem.eql(u8, val, "off")) config.ui_color = .off
@@ -337,6 +355,10 @@ pub fn main() void {
            catch |e| ui.die("Error opening directory: {s}.\n", .{ui.errorString(e)});
     if (out_file != null) return;
 
+    if (config.imported and !has_can_shell) config.can_shell = false;
+    if (config.imported and !has_can_delete) config.can_delete = false;
+    if (config.imported and !has_can_refresh) config.can_refresh = false;
+
     config.scan_ui = .full; // in case we're refreshing from the UI, always in full mode.
     ui.init();
     state = .browse;