Add CLI options for default sort

ncdu.pod

@@ -230,6 +230,20 @@ Set to I<off> to disable the shared size column for directories, I<shared>
 to display unique directory sizes as a separate column. These options can also
 be cycled through in the browser with the 'u' key.
 
+=item --sort I<COLUMN>
+
+Change the default column to sort on. Accepted values are I<disk-usage> (the
+default), I<name>, I<apparent-size>, I<itemcount> or I<mtime>. The latter only
+makes sense in extended mode, see C<-e>.
+
+The column can be suffixed with I<-asc> or I<-desc> to set the order to
+ascending or descending, respectively. e.g. C<--sort=name-desc> will sort by
+name in descending order.
+
+=item --group-directories-first, --no-group-directories-first
+
+Sort (or not) directories before files.
+
 =item --confirm-quit, --no-confirm-quit
 
 Require a confirmation before quitting ncdu. Very helpful when you accidentally

src/main.zig

@@ -305,7 +305,35 @@ pub fn main() void {
         else if(opt.is("--hide-graph")) config.show_graph = false
         else if(opt.is("--show-percent")) config.show_percent = true
         else if(opt.is("--hide-percent")) config.show_percent = false
-        else if(opt.is("--shared-column")) {
+        else if(opt.is("--group-directories-first")) config.sort_dirsfirst = true
+        else if(opt.is("--no-group-directories-first")) config.sort_dirsfirst = false
+        else if(opt.is("--sort")) {
+            var val: []const u8 = args.arg();
+            var ord: ?config.SortOrder = null;
+            if (std.mem.endsWith(u8, val, "-asc")) {
+                val = val[0..val.len-4];
+                ord = .asc;
+            } else if (std.mem.endsWith(u8, val, "-desc")) {
+                val = val[0..val.len-5];
+                ord = .desc;
+            }
+            if (std.mem.eql(u8, val, "name")) {
+                config.sort_col = .name;
+                config.sort_order = ord orelse .asc;
+            } else if (std.mem.eql(u8, val, "disk-usage")) {
+                config.sort_col = .blocks;
+                config.sort_order = ord orelse .desc;
+            } else if (std.mem.eql(u8, val, "apparent-size")) {
+                config.sort_col = .size;
+                config.sort_order = ord orelse .desc;
+            } else if (std.mem.eql(u8, val, "itemcount")) {
+                config.sort_col = .items;
+                config.sort_order = ord orelse .desc;
+            } else if (std.mem.eql(u8, val, "mtime")) {
+                config.sort_col = .mtime;
+                config.sort_order = ord orelse .asc;
+            } else ui.die("Unknown --sort option: {s}.\n", .{val});
+        } else if(opt.is("--shared-column")) {
             const val = args.arg();
             if (std.mem.eql(u8, val, "off")) config.show_shared = .off
             else if (std.mem.eql(u8, val, "shared")) config.show_shared = .shared