Often you'll need to pass a standard form genomic location (chr:bpA-bpB) but actually use the components. Splitting in bash is a pain, this does that for you. Assigning chr, bpA, and bpB to those variable names.

splitRegion.sh

# Here the function assumes you're passing a standard form genomic position (chr:bpA-bpB) as the first argument.
function splitRegion {
        IFS=':' read -ra REGION <<< "$1"
        chr="${REGION[0]}"
        IFS='-' read -ra LOCATION <<< "{REGION[1]}"
        bpA="${LOCATION[0]}"
        bpB="${LOCATION[1]}"
}

splitRegion $1
# chr, bpA, and bpB are now assigned.