From 6feb4b288f8fa9711ee580fe65562abef976a842 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Thu, 5 Sep 2019 18:06:53 +0200
Subject: [PATCH] color default depends on stdout being isatty

---
 graph | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/graph b/graph
index 423f5cb..14b7173 100755
--- a/graph
+++ b/graph
@@ -18,8 +18,9 @@ GetOptions(\my %opt,
 	'usage|h' => sub { podexit() },
 	'help'    => sub { podexit(-verbose => 2) },
 ) or exit 64;  # EX_USAGE
+
 $opt{width} ||= $ENV{COLUMNS} || 80;
-$opt{color} //= 1;
+$opt{color} //= -t *STDOUT;  # enable on tty
 
 if (defined $opt{follow}) {
 	$opt{follow} ||= 1;
@@ -108,9 +109,11 @@ Each line starting with a number is given a bar to visualise relative sizes.
 
 =over
 
-=item --no-color
+=item -c, --[no-]color
 
-Disable colored output of values and bar markers.
+Force colored output of values and bar markers.
+Defaults on if output is a tty,
+disabled otherwise such as when piped or redirected.
 
 =item -f, --follow[=<seconds>]
 
-- 
2.30.0