aria2c: A Multi-Protocol Download Utility

Overview

aria2c is a versatile tool that allows for efficient file downloads across various protocols. It excels at optimizing download speeds by utilizing multiple connections concurrently.

Key Features

Multi-protocol support (HTTP, HTTPS, FTP, SFTP, BitTorrent, Metalink)
Increased speed through multi-connection/multi-source downloads
Download resuming capability
Batch downloads from a file list
BitTorrent/Metalink support

Key Options

The main options of aria2c allow for fine-grained control over download methods, speed, and output.

Download Control

BitTorrent/Metalink

Generated command:

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Description:

`aria2c` Executes the command.

Combine the above options to virtually execute commands with AI.

Usage Examples

Practical examples of using aria2c's various features.

Basic HTTP/HTTPS File Download

aria2c https://example.com/archive.zip

Downloads a file from the specified URL.

Download File with Maximum 5 Connections

aria2c -x 5 https://example.com/large_file.tar.gz

Uses 5 concurrent connections to a single server to increase download speed.

Save File with a Specific Name

aria2c -o my_document.pdf https://example.com/document.pdf

Saves the downloaded file as 'my_document.pdf'.

Download BitTorrent File and Seed Indefinitely

aria2c --enable-dht --seed-time=0 torrent_file.torrent

Downloads a torrent file and seeds it indefinitely after completion. DHT is enabled to find peers.

Batch Download from a File List

aria2c -i urls.txt

Downloads all URLs from the 'urls.txt' file, where each line contains a single URL.

Specify Download Directory

aria2c -d /home/user/downloads https://example.com/another_file.iso

Saves downloaded files to the '/home/user/downloads' directory.

Installation

aria2c is not included by default in most Linux distributions and must be installed via a package manager.

Debian/Ubuntu

sudo apt update && sudo apt install aria2

Installs aria2c using the APT package manager.

Fedora/CentOS/RHEL

sudo dnf install aria2

Installs aria2c using the DNF (or Yum) package manager.

Arch Linux

sudo pacman -S aria2

Installs aria2c using the Pacman package manager.

Tips & Precautions

Tips and points to consider for more effective use of aria2c.

Performance Optimization

Increasing the number of connections per server using the `-x` option can improve download speeds. However, too many connections may burden the server, so adjust accordingly.
The `-s` option allows you to manage system resource usage by adjusting the maximum number of concurrent downloads when downloading multiple files simultaneously.

When Using BitTorrent

Enabling DHT (Distributed Hash Table) and Local Peer Discovery using options like `--enable-dht` and `--bt-enable-lpd` can help find more peers and increase download efficiency.
The `--seed-time=0` option continues seeding indefinitely after the download is complete. While this benefits other users, it continuously uses system resources (upload bandwidth), so be mindful of this.

Utilizing Configuration Files

You can create a `~/.aria2/aria2.conf` file to pre-configure frequently used options. For example, you can specify default connection counts, download directories, etc.
You can also specify a particular configuration file using the command `aria2c --conf-path=/path/to/aria2.conf`.