@@ -1,20 +1,96 @@
+#include <k/core.h>
 #include <k/cli.h>
 #include <k/io.h>
 #include <k/str.h>
+
+extern char* _k_internal_binary_name;
+
+static const struct { const char* front, * back; } param_styles [] = {
+	[kcli_rule_required] = { "<",">" },
+	[kcli_rule_optional] = { "[","]" },
+	[kcli_rule_overflow] = { "","..." },
+};
 
 kcond
 kcli_usage(kcli_set prg, kiochan ch) {
+	enum { max_name_len = 32 };
+
+	kcond c;
 	ubyte buf_space [sizeof(ksbuf) + 256];
 	ksbuf* out = ksbufmk(buf_space, ch, 256);
 
+	const char* name = prg.name != null ?
+		prg.name : _k_internal_binary_name;
+
 	const char* msg [] = {
-		prg.name, " v", prg.version, "\n\n",
+		name, " v", prg.version, "\n\n",
 		prg.desc, "\n\n",
+		"usage: ", _k_internal_binary_name,
+		prg.optc == 0 ? null : " [-",
 	};
-	for (sz i = 0; i != Kmsz(msg); ++ i) {
-		ksraw str = { 0, msg[i] };
-		kcond c = ksbufput(out, str);
+
+	if (!kokay(c = ksbufwrite(out, msg))) return c;
+
+	u8 longest_opt = 0;
+	u8 opt_lens [prg.optc];
+	for (sz i = 0; i != prg.optc; ++ i) {
+		if (prg.opts[i].id[0] == 0) continue;
+
+		opt_lens[i] = kssz(prg.opts[i].name, max_name_len);
+		if (opt_lens[i] > longest_opt)
+			longest_opt = opt_lens[i];
+
+		ksraw str = { kssz(prg.opts[i].id, 4), prg.opts[i].id };
+		if (!kokay(c = ksbufput(out, str))) return c;
 	}
+
+	if (!kokay(c = ksbufput(out, Ksraw("]")))) return c;
 	
+	u8 longest_param = 0;
+	u8 param_lens [prg.paramc];
+	for (sz i = 0; i != prg.paramc; ++ i) {
+		enum kcli_rule r = prg.params[i].rule;
+
+		param_lens[i] = kssz(prg.params[i].name, max_name_len);
+		if (param_lens[i] > longest_param)
+			longest_param = param_lens[i];
+
+		const char* param[] = {
+			" ", param_styles[r].front, prg.params[i].name,
+			param_styles[r].back, null
+		};
+
+		if (!kokay(c = ksbufwrite(out,param))) return c;
+	}
+
+	if (!kokay(c = ksbufput(out, Ksraw("\n")))) return c;
+
+	const char spacing [] = "                                ";
+	Kassert(sizeof spacing - 1 == max_name_len,
+			"spacing string not equal in length to max_name_len");
+	/* yes, yes, i know */
+
+	for (sz i = 0; i != prg.paramc; ++ i) {
+		u8 pad = (longest_param - param_lens[i]) + 1;
+		const char* tpl [] = {
+			"\n    ", spacing + (sizeof spacing - pad),
+			prg.params[i].name, ": ", prg.params[i].desc, null
+		};
+
+		if (!kokay(c = ksbufwrite(out, tpl))) return c;
+	}
+
+	if (!kokay(c = ksbufput(out, (ksraw){1, "\n"}))) return c;
+
+	for (sz i = 0; i != prg.optc; ++ i) {
+		u8 pad = (longest_opt - opt_lens[i]) + 1;
+		const char* tpl [] = {
+			"\n    -", prg.opts[i].id, ", --", prg.opts[i].name,
+			spacing + (sizeof spacing - pad), ": ", prg.opts[i].desc, null
+		};
+
+		if (!kokay(c = ksbufwrite(out, tpl))) return c;
+	}
+
 	return ksbufflush(out);
 }