Usage Sample ¶
Make sure that URI is quoted with single(') or double(") quotation if it contains "&" or any characters that have special meaning in shell.
As of 1.10.0 release, aria2 uses 1 connection per host by default and has 20MiB segment size restriction. So whatever value you specify using -s option, it uses 1 connection per host. Please note that this connection restriction is applied to 1 host. If you specify multiple hosts, aria2 will use them all and open multiple connections. To make it behave like 1.9.x, use -x16 -k1M. See --max-connection-per-server and --min-split-size in man page.
By default, aria2 allocates files before download them to prevent possible fragmentation. But it is reported that it uses 50%-90% CPU and slows down their PCs on some platforms.
If you are using newer file systems such as ext4(with extens enabled), btrfs or xfs, I recommend to use --file-allocation=falloc. It allocates large(few GiB) files almost instantly and it doesn't slow down your PC at all.
For linux users, specifying --enable-direct-io=true (enabled by default since 1.0.0) greatly reduces CPU usage to 1%.
If you are neither using cutting edge file systems nor Linux user and mind this slow down, turn off file allocation by giving --file-allocation=none.
If you forget about the full name of options or its details, put -h before the option or words in option name, like aria2c -hcrypt. aria2 searches options which contains specified words and print their usage. You can leave other options or URIs when using -h option. If aria2 finds -h, it stops after printing the help message.