bin/bright: New script

1 files changed, 80 insertions, 0 deletions

diff --git a/bin/bright b/bin/bright
new file mode 100755
index 0000000..04c83f5
--- /dev/null
+++ b/bin/bright
@@ -0,0 +1,80 @@
+#!/bin/sh
+
+set -eu
+
+get_b()
+{
+	# VCP 10 C 100 100
+	read -r vcp feat c val max <<-EOF
+		$(ddcutil -t getvcp 10)
+		EOF
+
+	printf '%s' ${val}
+	return 0
+}
+
+set_b()
+{
+	local b=${1}
+	shift 1
+
+	ddcutil setvcp 10 ${b}
+
+	return 0
+}
+
+inc_b()
+{
+	local d=${1}
+	shift 1
+	local b=
+
+	b=$(($(get_b) + ${d}))
+	if [ ${b} -gt 100 ]; then
+		b=100
+	elif [ ${b} -lt 0 ]; then
+		b=0
+	fi
+
+	set_b ${b}
+}
+
+usage()
+{
+	printf 'Usage: %s {<direction>|<value>}\n' "${0}"
+	printf '\n'
+	printf 'Where <direction> is any word beginning with (in any case):\n'
+	printf '  * "U" for up\n'
+	printf '  * "D" for down\n'
+	printf 'And <value> is any integer between 0 and 100 inclusive\n'
+
+	return 0
+}
+
+main()
+{
+	local dir=
+
+	if [ ${#} -ne 1 ]; then
+		usage 1>&2
+		return 1
+	fi
+
+	dir="${1}"
+	shift 1
+
+	case "${dir}" in
+		[Uu]*) inc_b 20;;
+		[Dd]*) inc_b -20;;
+		*[!0-9]* | '')
+			usage 1>&2
+			return 1
+			;;
+		*)
+			set_b ${dir}
+	esac
+
+	return 0
+}
+
+main "${@}"