password.ksh

#!/bin/ksh

# Cobbled together using https://www.romanzolotarev.com/random.html
# and https://docstore.mik.ua/orelly/unix3/korn/appb_11.htm

CHARS=' -~'
SIZE=20

USAGE="as#"
while getopts "$USAGE" opt; do
        case $opt in
                a) CHARS='[:alnum:]' ;;
                s) SIZE=$OPTARG
        esac
done

tr -cd "$CHARS" < /dev/urandom | fold -w $SIZE | head -n 1