Mirroring and Synchronizing

You can use the mirror command to move a folder or an entire directory tree to a server. Use lpwd to make sure that you are in the correct local directory. If necessary, change this with lcd. You can do the same with pwd and, if necessary, cd on the server side. The command to upload the directory is simply mirror -R, the reverse path from the server to the client works with mirror.

Alternatively, you can specify the directories with the

mirror -R /<Server folder>/ /<Client path>/

command. After the comparison, if you change a file or the file repository in the source directory and then execute the mirror command again, LFTP simply syncs the changes with the other side. The mirror command also supports several parallel connections, which you can initiate with mirror -P or define more precisely with:

mirror -parallel=<n>

LFTP plays to one of its strengths in the case of large volume transmissions, in particular by displaying a progress bar and the transmission speed, which you can reduce if required. If a transmission fails once, it can be resumed with the -c parameter, even if you terminated LFTP in the meantime.

Likewise, LFTP can handle several transmissions at the same time, and they can be sent off into the background as desired and then moved into the foreground again. To view details of the actions performed, take a look at the ~/.lftprc/ directory, where logs of all sessions that document the actions in detail reside.

When all work is complete, exit LFTP with exit or bye and return to the shell command line.

Advanced Functions

In addition to transferring files and directories between client and server, LFTP has many additional features and hundreds of control parameters. The most important commands are briefly summarized in Table 1.

For example, you can use the at <time> time control transmission parameter; queue lets you create queues; and -n <number> divides the file transmission into several parts. If you want to repeat an action later, create a bookmark with bookmark add <name>, and bookmark list lets you view all the bookmarks you have created.

Generally, you can initiate parallel transfers with -P (--parallel)=<n>. LFTP supports FXP transfers from server to server that excludes the client. You can download web pages with HTTP – even the Torrent protocol is supported. LFTP can also be controlled with scripts.

Conclusions

The very powerful and versatile LFTP is comparatively easy to master. Many commands are the same or similar to those of the shell or the conventional FTP command set. The application is still very much active, even after 20 years of development, as can be seen by the release of the fourth update in 2017.

LFTP, on the other hand, lacks up-to-date documentation. Many of the instructions found online are no longer correct. Nevertheless, if you appreciate the command line and want to or need to use FTP, I strongly recommend LFTP as a more powerful alternative.