lib/getopt: printusage + printhelp

Port ref/hare/getopt/getopts.ha:202-314 (printusage / _printusage / containsh /
printhelp): the two-pass io.empty width measurement + the >72-col indent rule.
Table-driven tests. cstage-only (C-first); wwstage byte-id twin owed (#125).
printsubcmds + parse() deferred (#127 / #126).

lib/getopt/getopttest.ww

@@ -22,6 +22,8 @@
 package getopt;
 
 import getopt;
+import io;
+import memio;
 import strings;
 
 // Direct exit(2) binding rather than `use os;` — os exports
@@ -391,6 +393,103 @@ fn streq(a: str, b: str) bool = {
 	};
 };
 
+// ---- printusage_cases: table of width-measure paths --------------------
+//
+// ref/hare/getopt/getopts.ha:202-265.
+// Row 0: short line (≤72) — auto-[-h] + FLAG cluster, no wrap.
+// Row 1: long line (>72) — PARAM slots each prefixed with \n\t.
+//
+// Help entries are packed into a flat [7]getopt.help array; hoff[i] /
+// hcnt[i] mark each row's slice. Parallel [2]str arrays hold name and
+// expected output per row.
+@test fn printusage_cases() void = {
+	let helps: [7]getopt.help;
+	// Row 0: CMD + FLAG 'F' + FLAG 'a'
+	getopt.cmdhelp(&helps[0], "list files");
+	getopt.flaghelp(&helps[1], 'F': rune, "do F");
+	getopt.flaghelp(&helps[2], 'a': rune, "do a");
+	// Row 1: CMD + 3 PARAMs (no-indent measurement 77 > 72)
+	getopt.cmdhelp(&helps[3], "process files");
+	getopt.paramhelp(&helps[4], 'e': rune, "expression", "run expr");
+	getopt.paramhelp(&helps[5], 'o': rune, "output-file", "output");
+	getopt.paramhelp(&helps[6], 'i': rune, "input-path", "input");
+
+	let names: [2]str;
+	let wants: [2]str;
+	let hoff:  [2]i32;
+	let hcnt:  [2]i32;
+
+	names[0] = "ls";
+	wants[0] = "Usage: ls [-hFa]\n";
+	hoff[0] = 0; hcnt[0] = 3;
+
+	names[1] = "myprogram";
+	wants[1] = "Usage: myprogram [-h]\n\t [-e <expression>]\n\t [-o <output-file>]\n\t [-i <input-path>]\n";
+	hoff[1] = 3; hcnt[1] = 4;
+
+	let buf: [512]u8;
+	let i: i32 = 0;
+	for (i < 2) {
+		let ms: memio.stream = memio.fixed(buf[0:512]);
+		let s: io.stream = &ms.vt;
+		let h: io.handle = s: io.handle;
+		let hs: []getopt.help;
+		hs.ptr = &helps[hoff[i]];
+		hs.len = hcnt[i];
+		hs.cap = hcnt[i];
+		match (getopt.printusage(h, names[i], hs)) {
+		case void => {};
+		case let e: io.error => fail();
+		};
+		let got: str = memio.string(&ms);
+		if (!streq(got, wants[i])) { fail(); };
+		i += 1;
+	};
+};
+
+// ---- printhelp_cases: table of help-output paths ----------------------
+//
+// ref/hare/getopt/getopts.ha:281-314.
+// Row 0: empty help slice → early return, no output.
+// Row 1: full help (CMD+FLAG+PARAM+CMD) → summary + usage + option list.
+//
+// help[0..4] holds the full-case entries; the empty-case uses a 0-len
+// slice from the same array (hcnt[0]=0).
+@test fn printhelp_cases() void = {
+	let helps: [4]getopt.help;
+	getopt.cmdhelp(&helps[0], "concatenate files");
+	getopt.flaghelp(&helps[1], 'n': rune, "number lines");
+	getopt.paramhelp(&helps[2], 'o': rune, "output", "output file");
+	getopt.cmdhelp(&helps[3], "files...");
+
+	let names: [2]str;
+	let wants: [2]str;
+	let hcnt:  [2]i32;
+
+	names[0] = "prog";
+	wants[0] = "";
+	hcnt[0] = 0;
+
+	names[1] = "cat";
+	wants[1] = "cat: concatenate files\n\nUsage: cat [-hn] [-o <output>] files...\n\n-h: print this help text\n-n: number lines\n-o <output>: output file\n";
+	hcnt[1] = 4;
+
+	let buf: [512]u8;
+	let i: i32 = 0;
+	for (i < 2) {
+		let ms: memio.stream = memio.fixed(buf[0:512]);
+		let s: io.stream = &ms.vt;
+		let h: io.handle = s: io.handle;
+		match (getopt.printhelp(h, names[i], helps[0:hcnt[i]])) {
+		case void => {};
+		case let e: io.error => fail();
+		};
+		let got: str = memio.string(&ms);
+		if (!streq(got, wants[i])) { fail(); };
+		i += 1;
+	};
+};
+
 export fn main() i32 = {
 	signalled = 1; flagcluster();
 	signalled = 2; paramflag();
@@ -400,5 +499,7 @@ export fn main() i32 = {
 	signalled = 6; errortable();
 	signalled = 7; strerrortext();
 	signalled = 8; nooptionsbare();
+	signalled = 9;  printusage_cases();
+	signalled = 10; printhelp_cases();
 	return 0;
 };