[BASH] check the number of function parameters

gistfile1.sh

#!/bin/bash
# -*- coding: UTF8 -*-

function usage() {
echo "$(basename ${0}) <first_arg> <second_arg>";
    echo "";
    echo "<first_arg>   the first argument";
    echo "<second_arg>  the second argument";
}

function main() {
    shift;
    local first="${1}";
    local second="${2}";

    echo "first: $first"
    echo "second: $second";
}

ARGC="${#}";
ARGV="${@}";

function run_with_at_least() {
[ $4 -ge $1 ] && $2 $4 $5 || $3;
}

run_with_at_least 2 "main" "usage" $ARGC "$ARGV"