lftp to accelerate ftp / http download speed under Linux and UNIX

in Categories CentOS, Debian Linux, FreeBSD, Gentoo Linux last updated August 10, 2007

lftp is a file transfer program that allows sophisticated ftp, http and other connections to other hosts. If site is specified then lftp will connect to that site otherwise a connection has to be established with the open command. This is an essential tool for all a Linux admin. I’ve already written about Linux ultra fast command line download accelerator such as Axel and prozilla. lftp is another tool for same job with more features.

lftp can handle seven file access methods :
=> ftp
=> ftps
=> http
=> https
=> hftp
=> fish
=> sftp
=> file

So what’s special about lftp?

  • Every operation in lftp is reliable, that is any not fatal error is ignored and the operation is repeated. So if downloading breaks, it will be restarted from the
    point automatically. Even if ftp server does not support REST command, lftp will try to retrieve the file from the very beginning until the file is transferred completely.
  • lftp has shell-like command syntax allowing you to launch several commands in parallel in background
  • lftp has builtin mirror which can download or update a whole directory tree. There is also reverse mirror (mirror -R) which uploads or updates a directory tree on server. Mirror can also synchronize directories between two remote servers, using FXP if available.

Use lftp as download accelerator

lftp has pget command. It allows you download files in parallel. lftp pget command syntax:
lftp -e ‘pget -n 5 ftp://path/to/file

For example, download http://kernel.org/pub/linux/kernel/v2.6/linux- file using pget in 5 parts:
$ cd /tmp
$ lftp -e 'pget -n 5 http://kernel.org/pub/linux/kernel/v2.6/linux-'


45108964 bytes transferred in 57 seconds (775.3K/s)
lftp :~>quit

A note about parallel downloading

Please note that by using download accelerator you are going to put a load on remote host. Also note that lftp may not work with sites that do not support multi-source downloads or blocks such requests at firewall level.

lftp command offers many other features. Refer to lftp man page for more information:
man lftp