TITLE: Configuring Ranger, a File Manager for macOS, with rifle.conf
DATE: 2017-07-20
AUTHOR: John L. Godlee
====================================================================


Ranger is a file manager for the terminal and my default file 
manager since I moved away from Midnight Commander (mc). Most of my 
work I do on a MacBook Pro and I found that opening files that 
weren't text editor compatible was difficult, pressing on the 
highlighted files merely returned an open with: prompt, and nothing 
I typed seemed to work.

  ![Ranger 
screenshot](https://johngodlee.xyz/img_full/ranger/ranger_scrot.png)

I found out that rifle.conf is the config file which controls how 
Ranger opens files. It is normally found in 
~/.config/ranger/rifle.conf.

The default rifle.conf however is dense, complex and doesn't play 
well with an ordinary mac setup.

So I decided to try and strip down rifle.conf and rebuild it for 
use on macOS. If you want to skip straight to the rifle.conf that I 
use, follow this link.

  [follow this link](https://johngodlee.xyz/files/ranger/rifle.conf)

Now open up your own rifle.conf and start editing:

    vim ~/.config/ranger/rifle.conf

The pre-amble comments give examples of how to set up the file, but 
this took me a while to understand. I finally decided to remove 
everything and start from scratch.

rifle.conf is structured so each line provides a set of conditions 
separated by commas (,) e.g. ext mp3, followed by an equals =, then 
a terminal command, e.g. vlc $@. When Ranger is asked to open a 
file, it cycles through every line from top to bottom until it 
finds a line where all the conditions are met, then it runs the 
terminal command. This means that the top-most line where all the 
conditions are met will be run. Using this logic you can construct 
a rifle.conf that works on different systems, if you order 
potential applications from most to least preferred.

Using open

ost Linux applications can simply be opened by typing their name 
into the terminal, optionally followed by a file to open and 
various rules, e.g. zathura example.pdf. In macOS however, typing 
the equivalent preview example.pdf just returns an error that 
preview has not been found. The same goes for Preview, preview.app 
and Preview.app.

Instead, on a Mac, I find the best way to call an application from 
the command line is to use open.

The following lines all open Preview.app:

    open -a preview
    open -a preview.app
    open -a Preview
    open -a Preview.app

And to open example.pdf just add the file name:

    open -a preview example.pdf

This same syntax can be applied to rifle.conf to open specific apps 
for specific file types with Ranger.

The simplest condition to use is the file extension (ext):

    ext pdf = open -a preview "$@"

Where "$@" is the file path of the file highlighted in Ranger The 
above there says, if the file extension is .pdf, open the file with 
Preview.app.

Regex

Regular expressions can be used to make more complex conditions, 
e.g. using | to include multiple file extensions in one line, or [] 
and ? to list similar extensions without repetition. Try to work 
out what the conditions below mean.

    ext jpe?g|png|gif = open -a preview "$@"
    ext od[dfgpst] = open -a libreoffice "$@"

MIME types

IME types are a good last resort for catching any files with 
unusual extensions, I normally put them at the bottom of a list of 
preferred applications, to open with a program I know will be 
installed, for example:

    ext xml|json|py|pl|rb|js|sh|php|m[ark]d[own]|txt = vim "$@" 
    ext tex = open -a texworks "$@"
    mime ^text = nano "$@"

The has condition

For the majority of GUI applications on a Mac, the has condition 
does not work, for the same reason that calling applications 
directly from the terminal by typing their name doesn't work, 
because Ranger can't find them. As far as I know, there isn't any 
way to get around this. Maybe if you could check for the presence 
of the named directory in ~/Applications, but I haven't worked that 
out yet.

Taking advantage of LaunchServices defaults

Finally, a good line to keep at the end of rifle.conf is:

    flag f = open "$@"

This takes advantage of open using macOS LaunchServices to decide 
the default application when the user doesn't specify one using -a. 
This should catch everything that you haven't listed specifically. 
I suppose you could just have a rifle.conf with only this line and 
everything would still work as if you were using a GUI, files would 
be opened with the default Mac GUI application as if you had double 
clicked on it in Finder.

Formatting

To increase readability I try to split my rifle.conf into sections, 
so I don't get mixed up with my program heirarchies, for example:

    #-------------------------------------------
    # Web material
    #-------------------------------------------
    ext x?html?, X, flag f = open -a Safari "$@"
    ext x?html?, has w3m, terminal = w3m "$@"

    #-------------------------------------------
    # Text files
    #-------------------------------------------
    ext xml|json|tex|py|pl|rb|js|sh|php|m[ark]d[own]|txt = vim "$@"
    mime ^text = vim "$@"

    #--------------------------------------------
    # Audio without X
    #-------------------------------------------
    ext mp3 = /Applications/VLC.app/Contents/MacOS/VLC --intf 
ncurses  "$@"

A final tip

If you find yourself switching between Finder and Ranger a lot, 
especially as you transition to the terminal, adding this 
keybinding to ~/.config/ranger/rc.conf will allow you to open 
Finder on the highlighted file with %:

    map % shell open -R %s

It opens the shell prompt and uses open to call Finder (-R) on the 
highlighted file (%s). You could do similar if you wanted to 
quickly specify a non-default editor for a file:

    map te shell open -a textedit %s