feat: add center

scripts/center

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+# Produces a centered text based on HRULEWIDTH environment variable.
+
+: "${HRULEWIDTH:=73}"
+
+_filter() {
+	[[ -n "$1" ]] && return 1
+	while IFS= read -ra args; do
+		"${FUNCNAME[1]}" "${args[@]}"
+	done
+}
+
+center() {
+	_filter "$@" && return $?
+	local str="$1" char="${2:- }"
+	local -i len=${#str}
+	local -i side=$((((HRULEWIDTH / 2) - len / 2) - 3))
+	local -i left=$side
+	local -i right=$side
+	((len % 2 == 1)) && ((right -= 1))
+	echo "$pre $(echon "$char" "$left") "$str" $(echon "$char" "$right")"
+}
+
+center "$@"