[shell] subcommand sample

subcommand.sh

#!/bin/sh
######################################################################
#
# SHELL subcommand and argument sample
#
# USAGE: 
#        bash asd.sh A
#        bash asd.sh B 123
######################################################################


function A {
    echo "A"
}

function B {
    input=$1
    echo ${input}
}

subcmd="$1"
shift

case "$subcmd" in
  "A")
    A "$@"
    ;;
  "B")
    B "$@"
    ;;
  *)
    echo "[!] Unknown subcommand"
    exit 1
    ;;
esac