Convert each line to hash

convert_each_line_to_hash.sh

#!/bin/bash

usage() {
    echo "Usage: $0 -i [INPUT] -o [OUTPUT] -a [HASH_ALGORITHM]"
    1>&2;
    exit 1;
}

input=""
output=""
algo=""

OPTIND=1

while getopts ":i:o:a:" opt; do
    case "$opt" in
        i)
            input=${OPTARG}
            ;;
        o)
            output=${OPTARG}
            ;;
        a)
            algo=${OPTARG}
            ;;
    esac
done

shift $((OPTIND-1))

[ "${1:-}" = "--" ] && shift

if [ -z "${input}" ] || [ -z "${output}" ] || [ -z "${algo}" ]; then
    usage
    exit 1
fi

while read p; do
    echo -n "$p" | "${algo}"sum | cut -d ' ' -f 1 >> "${output}"
done < "${input}"