Mailcap

lf works very well with Mailcap as a launcher and a previewer. It is an attractive option once you realize it is already installed on most systems (mailcap is part of the mime-support package, which is a pretty common dependency).

~/.mailcap

The mailcap file allows to define for each MIME types a default action. Example:

video/*; mpv '%s';
audio/*; mpv '%s';
text/*; vim '%s'; needsterminal;

The default action is invoked with run-mailcap file.txt.

We can also define alternate actions like the print action. The print action is invoked with run-mailcap --action=print file.txt or by the default wrapper print file.txt. In the following example we add print actions to our mailcap file with the intent to use print as a lf previewer.

video/*; mpv '%s'; print=mpv --aid=no --vid=no --sid=no '%s' || : ;
audio/*; mpv '%s'; print=mpv --aid=no --vid=no --sid=no '%s' || : ;
text/*; vim '%s'; needsterminal; print=less '%s';

lf integration

In order to use mailcap as a launcher we just need to set the following environment variable:

OPENER=run-mailcap

And in order to use mailcap as a previewer we just need to set the following lf option:

set previewer print

Alternative launcher

The default way to open a file using mailcap is using the run-mailcap tool. It comes preinstalled on OpenBSD and is available as an AUR package. The latest version appears to be unable to cope with path containing spaces.

To circumvent this issue an alternative implementation can be used. The run-mailcap-rs is a recent Rust rewrite of run-mailcap and can handle paths with spaces without problems.