Ruby: Add method KernAux.cmdline

pkgs/ruby/ext/default/extconf.rb

@@ -16,4 +16,6 @@ have_func 'kernaux_itoa10'
 
 have_func 'kernaux_snprintf'
 
+have_func 'kernaux_cmdline'
+
 raise 'can\'t create Makefile' unless create_makefile 'kernaux/default'

pkgs/ruby/ext/default/main.c

@@ -5,6 +5,8 @@
 #include <ruby.h>
 
 static VALUE rb_KernAux = Qnil;
+static VALUE rb_KernAux_Error = Qnil;
+static VALUE rb_KernAux_CmdlineError = Qnil;
 
 static void assert_cb(const char *file, int line, const char *str);
 
@@ -24,9 +26,17 @@ static VALUE rb_KernAux_itoa10(VALUE self, VALUE number);
 static VALUE rb_KernAux_snprintf1(int argc, VALUE *argv, VALUE self);
 #endif
 
+#ifdef HAVE_KERNAUX_CMDLINE
+static VALUE rb_KernAux_cmdline(VALUE self, VALUE cmdline);
+#endif
+
 void Init_default()
 {
     rb_KernAux = rb_define_module("KernAux");
+    rb_KernAux_Error =
+        rb_define_class_under(rb_KernAux, "Error", rb_eRuntimeError);
+    rb_KernAux_CmdlineError =
+        rb_define_class_under(rb_KernAux, "CmdlineError", rb_KernAux_Error);
 
     kernaux_assert_cb = assert_cb;
 
@@ -48,6 +58,10 @@ void Init_default()
     rb_define_singleton_method(rb_KernAux, "snprintf1",
                                rb_KernAux_snprintf1, -1);
 #endif
+
+#ifdef HAVE_KERNAUX_CMDLINE
+    rb_define_singleton_method(rb_KernAux, "cmdline", rb_KernAux_cmdline, 1);
+#endif
 }
 
 void assert_cb(const char *const file, const int line, const char *const str)
@@ -216,3 +230,12 @@ VALUE rb_KernAux_snprintf1(
     return rb_funcall(result_rb, rb_intern("freeze"), 0);
 }
 #endif
+
+#ifdef HAVE_KERNAUX_CMDLINE
+VALUE rb_KernAux_cmdline(VALUE self_rb, VALUE cmdline_rb)
+{
+    Check_Type(cmdline_rb, T_STRING);
+    rb_raise(rb_KernAux_CmdlineError, "test");
+    return Qnil;
+}
+#endif

pkgs/ruby/lib/kernaux.rb

@@ -49,6 +49,13 @@ module KernAux
   # @see .panic
   #
   class AssertError < Error; end
+
+  ##
+  # Raised when command line parsing goes wrong.
+  #
+  # @see .cmdline
+  #
+  class CmdlineError < Error; end
 end
 
 # Native extension