add +show-config action to print out the config from the cli

src/cli/action.zig

@@ -8,6 +8,7 @@ const version = @import("version.zig");
 const list_keybinds = @import("list_keybinds.zig");
 const list_themes = @import("list_themes.zig");
 const list_colors = @import("list_colors.zig");
+const show_config = @import("show_config.zig");
 
 /// Special commands that can be invoked via CLI flags. These are all
 /// invoked by using `+<action>` as a CLI flag. The only exception is
@@ -31,6 +32,9 @@ pub const Action = enum {
     /// List named RGB colors
     @"list-colors",
 
+    /// Dump the config to stdout
+    @"show-config",
+
     pub const Error = error{
         /// Multiple actions were detected. You can specify at most one
         /// action on the CLI otherwise the behavior desired is ambiguous.
@@ -119,6 +123,7 @@ pub const Action = enum {
             .@"list-keybinds" => try list_keybinds.run(alloc),
             .@"list-themes" => try list_themes.run(alloc),
             .@"list-colors" => try list_colors.run(alloc),
+            .@"show-config" => try show_config.run(alloc),
         };
     }
 

src/cli/show_config.zig

@@ -0,0 +1,46 @@
+const std = @import("std");
+const args = @import("args.zig");
+const Allocator = std.mem.Allocator;
+const Config = @import("../config/Config.zig");
+
+pub const Options = struct {
+    /// If true, print out the default config instead of the user's config.
+    default: bool = false,
+
+    pub fn deinit(self: Options) void {
+        _ = self;
+    }
+};
+
+/// The "show-config" command is used to list all the available configuration
+/// settings for Ghostty.
+///
+/// When executed without any arguments this will list the current settings
+/// loaded by the config file(s). If no config file is found or there aren't
+/// any changes to the settings it will print out the default ones configured
+/// for Ghostty
+///
+/// The "--default" argument will print out all the default settings
+/// configured for Ghostty
+pub fn run(alloc: Allocator) !u8 {
+    var opts: Options = .{};
+    defer opts.deinit();
+
+    {
+        var iter = try std.process.argsWithAllocator(alloc);
+        defer iter.deinit();
+        try args.parse(Options, alloc, &opts, &iter);
+    }
+
+    var config = if (opts.default) try Config.default(alloc) else try Config.load(alloc);
+    defer config.deinit();
+
+    const stdout = std.io.getStdOut().writer();
+
+    const info = @typeInfo(Config);
+    std.debug.assert(info == .Struct);
+
+    try config.formatConfig(stdout);
+
+    return 0;
+}