apps: Add arch

apps/CMakeLists.txt

@@ -53,3 +53,4 @@ luna_app(startui.cpp startui)
 luna_app(launch.cpp launch)
 luna_app(run.cpp run)
 luna_app(sha256sum.cpp sha256sum)
+luna_app(arch.cpp arch)

apps/arch.cpp

@@ -0,0 +1,22 @@
+#include <os/ArgumentParser.h>
+#include <os/File.h>
+#include <sys/utsname.h>
+
+Result<int> luna_main(int argc, char** argv)
+{
+    os::ArgumentParser parser;
+    parser.add_description("Print the current machine's architecture name."_sv);
+    parser.add_system_program_info("arch"_sv);
+    parser.parse(argc, argv);
+
+    struct utsname info;
+    if (uname(&info) < 0)
+    {
+        perror("uname");
+        return 1;
+    }
+
+    os::println("%s", info.machine);
+
+    return 0;
+}