Usage
run bundle to install dependencies first
then ruby ./main.rb pics.txt to download files from pics.txt to ./downloads folder
you can specify download destination ruby ./main.rb pics.txt ~/Downloads for example
Overview
main.rb is the entry point script of the downloader. It processes command line args and ties other modules together.
ChunkedDownload downloads individual files in chunks using net/http and writes it in chunks to the destination file. It avoids reading the whole file into memory reducing memory footprint.
ReadLines reads file with links and parallelizes its'
processing using Concurrent::Promise from concurrent-ruby.
LineCount calculates number of lines in a text file. It's
used to create progress bar. I chose to use wc -l to calculate it. It is more
efficient than IO.foreach for example. It's main drawback
is that it's usable only in Unix-like environments.