+TIMESPAN="24h"
+
+USAGE="Usage: $(basename "$0") [-h] [-t val]
+Simple bash script to visualize the value of your bitcoin investment.
+
+Arguments:
+ -h show this help text
+ -t set the timespan (default: $TIMESPAN)"
+
+while getopts ':ht:' option; do
+ case "$option" in
+ h) echo "$USAGE"
+ exit
+ ;;
+ t) TIMESPAN=$OPTARG
+ ;;
+ :) printf "missing argument for -%s\n" "$OPTARG" >&2
+ echo "$usage" >&2
+ exit 1
+ ;;
+ \?) printf "illegal option: -%s\n" "$OPTARG" >&2
+ echo "$usage" >&2
+ exit 1
+ ;;
+ esac
+done
+shift $((OPTIND - 1))
+