bash script to download large files from google drive

gdown.sh

#!/bin/bash

## description: script to download large files from google drive 
## version 0.1
## author: 0i0 (https://github.com/0i0)

usage="$(basename "$0") [-h] link filename-- program to download a file from google drive link

where:
    -h  show this help text
    link  set the link
    filename  set the filename"

while getopts ':h' option; do
  case "$option" in
    h) echo "$usage"
       exit
       ;;
  esac
done
if [ -z "$1" ]
  then
    echo "No argument supplied"
    echo "$usage"
    exit
fi
if [ -z "$2" ]
  then
    echo "No filename supplied"
    echo "$usage"
    exit
fi
if [[ ! $1 = *"https://drive.google.com"* ]]; then
  echo "not sure its a google drive link
was looking for  https://drive.google.com
  "
  exit
fi

# get the query strin
query=$(echo $1|awk -F\? '{print $2}')

# parse the query string to get id
saveIFS=$IFS
IFS='=&'
parm=($query)
IFS=$saveIFS
for ((i=0; i<${#parm[@]}; i+=2))
do
    declare var_${parm[i]}=${parm[i+1]}
done


id=$var_id
filename=$2

echo "Downloading $1"
wget --load-cookies /tmp/cookies.txt "https://docs.google.com/uc?export=download&confirm=$(wget --quiet --save-cookies /tmp/cookies.txt --keep-session-cookies --no-check-certificate 'https://docs.google.com/uc?export=download&id='$id -O- | awk -F"confirm=" '{printf substr($2,0,5)}')&id="$id -O $filename && rm -rf /tmp/cookies.txt