# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1680867197 -3600
# Node ID 5bd2720953886bfd22b82fdab6a9a24af1ca56c2
# Parent  d4f7118d15315933a38c1be4a3822b250c2dd752
util.human.io: Add term_width() method to discover the terminal width

This is not standard POSIX, but apparently very widely supported. For
reference: https://www.austingroupbugs.net/view.php?id=1053

diff -r d4f7118d1531 -r 5bd272095388 util/human/io.lua
--- a/util/human/io.lua	Fri Apr 07 13:09:00 2023 +0200
+++ b/util/human/io.lua	Fri Apr 07 12:33:17 2023 +0100
@@ -108,6 +108,17 @@
 	end
 end
 
+local function term_width(default)
+	local stty = io.popen("stty -a");
+	if not stty then return default; end
+	local result = stty:read("*a");
+	if result then
+		result = result:match("%f[%w]columns[ =]*(%d+)");
+	end
+	stty:close();
+	return tonumber(result or default);
+end
+
 local function ellipsis(s, width)
 	if len(s) <= width then return s; end
 	if width == 1 then return "…"; end
@@ -194,6 +205,7 @@
 	printf = printf;
 	padleft = padleft;
 	padright = padright;
+	term_width = term_width;
 	ellipsis = ellipsis;
 	table = new_table;
 };