Simply download courses from git.ir

gitir_dl.sh

#!/bin/env bash

# Author: https://github.com/runo280

# How to use: ./gitit_dl.sh https://git.ir/your_course_name/

# Valid pattern for url: https://git.ir/your_course_name/

# Needed packages: aria2, wget, sed, cut, grep, rev

echo
echo "............................"
echo ". git.ir course downloader ."
echo "............................"
echo

if [ -z "$1" ]; then
	echo "Url is missing!"
fi

url=$1
links_file=links.txt
folder=$(echo $url | rev | cut -d '/' -f 2 | rev)

function extract_links(){
	echo "Start extracting links..."
	content=$(wget $url -q -O -)
	echo $content | grep -o '<a href=['"'"'"][^"'"'"']*['"'"'"]' | sed -e 's/^<a href=["'"'"']//' -e 's/["'"'"']$//' | sed -e '/.mp4/!d' > $folder/$links_file
}

function download(){
	echo "Start downloading..."
	cd $folder
	aria2c --max-concurrent-downloads=1 --continue --max-connection-per-server=16 --min-split-size=1M --split=16 --download-result=full --enable-color=true --human-readable=true --check-certificate=false -i $links_file
	#wget -i $links_file
	echo "Download finished"
}

if [ ! -d "$folder" ]; then
	mkdir $folder
fi

if [ -f "$folder/$links_file" ]; then
	echo "links.txt exists"
	download
else
	extract_links
	download
fi

How to use this code?