1 files changed, 42 insertions, 2 deletions

diff --git a/src/main.zig b/src/main.zig
index 30aacca..1511740 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -7,16 +7,56 @@ const stdin = &stdin_reader.interface;
 var stdout_writer = std.fs.File.stdout().writerStreaming(&.{});
 const stdout = &stdout_writer.interface;
 
+const CommandResult = enum {
+    continue_loop,
+    exit_shell,
+};
+
+fn parseCommand(input: []const u8) struct { name: []const u8, args: ?[]const u8 } {
+    const space_pos = std.mem.indexOfScalar(u8, input, ' ');
+    if (space_pos) |pos| {
+        return .{
+            .name = input[0..pos],
+            .args = input[pos + 1 ..],
+        };
+    }
+    return .{
+        .name = input,
+        .args = null,
+    };
+}
+
+fn executeCommand(cmd_name: []const u8, args: ?[]const u8) !CommandResult {
+    if (std.mem.eql(u8, cmd_name, "exit")) {
+        return .exit_shell;
+    }
+
+    if (std.mem.eql(u8, cmd_name, "echo")) {
+        if (args) |a| {
+            try stdout.print("{s}\n", .{a});
+        } else {
+            try stdout.print("\n", .{});
+        }
+        return .continue_loop;
+    }
+
+    // Command not found
+    try stdout.print("{s}: command not found\n", .{cmd_name});
+    return .continue_loop;
+}
+
 pub fn main() !void {
     while (true) {
         try stdout.print("$ ", .{});
 
         const command = try stdin.takeDelimiter('\n');
         if (command) |cmd| {
-            if (std.mem.eql(u8, cmd, "exit")) {
+            const parsed = parseCommand(cmd);
+            const result = try executeCommand(parsed.name, parsed.args);
+
+            if (result == .exit_shell) {
                 break;
             }
-            try stdout.print("{s}: command not found\n", .{cmd});
         } else {
             break;
         }