terminal download shell script

#!/bin/bash

# Script Function
url () {
    printf '\033[033mURL: \033[m'
    echo $*
}

#//+ ITS_ function to easily check the,
#// operating systems presense of any needed package.

#/#/ Define any tools needed here seperated only by a "\:space:"\
needed_tool=' youtube-dl aria2c '

#//* Begin System Tool Search
require_tools ()
{
    local NOT_AVAIL=""
    for TOOL in $needed_tool; do
        if [ "`which $TOOL 2> /dev/null`" == "" ]; then NOT_AVAIL="$NOT_AVAIL $TOOL"; fi
    done
    if [[ "$NOT_AVAIL" != "" ]]; then
        echo "ERROR: The following required tool(s) cannot be found: $NOT_AVAIL"
        exit 3
    fi
}

# Check file system tools before we start
require_tools

# Script Variables
FILE=`echo "youtube-dl -c -i --yes-playlist --ignore-config --external-downloader aria2c"`
FILE_1=`echo $FILE > /tmp/termdl`
FILE_DL=`cat /tmp/termdl`

# Start
# echo -e "Copy Paste Videos/URL:"
url
read URL
$FILE_DL "$URL"

# Finish and exit
exit