1 files changed, 41 insertions, 0 deletions
diff --git a/src/builtins.zig b/src/builtins.zig
new file mode 100644
index 0000000..c989a35
--- /dev/null
+++ b/src/builtins.zig
@@ -0,0 +1,41 @@
+const std = @import("std");
+const path = @import("path.zig");
+
+const BUILTINS = [_][]const u8{ "exit", "echo", "type" };
+
+pub const CommandResult = enum {
+    continue_loop,
+    exit_shell,
+};
+
+pub fn isBuiltin(cmd_name: []const u8) bool {
+    for (BUILTINS) |builtin| {
+        if (std.mem.eql(u8, cmd_name, builtin)) return true;
+    }
+    return false;
+}
+
+pub fn executeExit() CommandResult {
+    return .exit_shell;
+}
+
+pub fn executeEcho(stdout: anytype, args: ?[]const u8) !void {
+    if (args) |a| {
+        try stdout.print("{s}\n", .{a});
+    } else {
+        try stdout.print("\n", .{});
+    }
+}
+
+pub fn executeType(allocator: std.mem.Allocator, stdout: anytype, args: ?[]const u8) !void {
+    if (args) |a| {
+        if (isBuiltin(a)) {
+            try stdout.print("{s} is a shell builtin\n", .{a});
+        } else if (try path.findInPath(allocator, a)) |cmd_path| {
+            defer allocator.free(cmd_path);
+            try stdout.print("{s} is {s}\n", .{ a, cmd_path });
+        } else {
+            try stdout.print("{s}: not found\n", .{a});
+        }
+    }
+}