codecrafters submit [skip ci]

2 files changed, 16 insertions, 3 deletions

diff --git a/src/builtins.zig b/src/builtins.zig
index 011a923..18e1840 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -116,8 +116,21 @@ pub fn executeType(allocator: std.mem.Allocator, stdout: anytype, args: ?[]const
     }
 }
 
-pub fn executeHistory(stdout: anytype, history_list: []const []const u8) !void {
-    for (history_list, 1..) |cmd, idx| {
+pub fn executeHistory(stdout: anytype, history_list: []const []const u8, args: ?[]const u8) !void {
+    var limit: usize = history_list.len;
+
+    if (args) |a| {
+        const trimmed = std.mem.trim(u8, a, " ");
+        if (trimmed.len > 0) {
+            limit = std.fmt.parseInt(usize, trimmed, 10) catch {
+                try stdout.print("history: invalid argument\n", .{});
+                return;
+            };
+        }
+    }
+
+    const start = if (limit < history_list.len) history_list.len - limit else 0;
+    for (history_list[start..], start + 1..) |cmd, idx| {
         try stdout.print("    {d}  {s}\n", .{ idx, cmd });
     }
 }
diff --git a/src/shell.zig b/src/shell.zig
index 6f8bfef..bd50ff1 100644
--- a/src/shell.zig
+++ b/src/shell.zig
@@ -24,7 +24,7 @@ pub fn executeCommand(
     if (std.mem.eql(u8, cmd_name, "exit")) return builtins.executeExit();
 
     if (std.mem.eql(u8, cmd_name, "history")) {
-        try builtins.executeHistory(stdout, history_list);
+        try builtins.executeHistory(stdout, history_list, args);
         return .continue_loop;
     }