slopen is a simple and user-friendly alternative to xdg-open.

In Linux, the de-facto standard utility to open a file with default application is xdg-open. Although xdg-open is easy to use, configuration is complicated: you need to create .desktop files and debugging its behaviour is a nightmare.

slopen is an alternative with a single simple configuration file. When it doesn't find a suitable command for a file, the user is prompted, either directly in the terminal or with dmenu.

If you want to open foo.png, just type

slopen foo.png

and it will choose the right program to open it according to your ~/.slopenrc. When no rules in ~/.slopenrc matches the file, it will ask the user either in terminal or with dmenu, depending on whether slopen is run from a terminal or not.

1. ksh
2. dmenu

Both should be in package repositories in most Linux distribution.

1. Drop the slopen into your $PATH.
2. Create ~/.slopenrc (for example, see slopenrc.example)

slopen scans through the 'rules' in ~/.slopenrc one-by-one to decide which command to use to open a file. Each rule should look like

 <type>: <regex> : <command>

Type can be either M and S. If type is 'M' then regular expression is matched on the MIME type. If it is 'S' then it matches file name instead. Whitespaces around the delimiter ':' is ignored.

If multiple rules matches a file, the first rule is always used. Lines started with '#' are ignored.

Example:

 S: .*\.ps$                  :  zathura
 S: .*\.pdf$                 :  zathura
 S: .*\.png$                 :  qiv
 M: ^inode/directory$        :  rox
 M: ^text/.*                 :  emacs

With this config file, say, when you call slopen ~, it will invoke rox ~.

While it is possible to just replace the xdg-open executable with slopen, this is usually not enough to change the behaviour of some applications such as Firefox, which uses the C API directly to access the default application database instead of accessing it through the xdg-open binary.

Since too many applications is using the same xdg-mime database through different interfaces, perhaps the easiest way to make everything use slopen is to directly setting the default application of every MIME types to slopen in the xdg-mime database. Doing this will also makes xdg-open forward everything to slopen.

To do this, create the file ~/.local/share/applications/slopen.desktop with the following content:

[Desktop Entry]
Name=Slopen
Exec=slopen %F
Type=Application

Then use the following command to set the default application of all known MIME types to slopen.desktop:

find /usr/share/applications ~/.local/share/applications \
     -type f -name '*.desktop' \
     -exec awk 'match($0, /^MimeType=(.*)/, m) {\
     	   split(m[1],t,";");\
	   for (i in t) \
	       if (t[i]!="") \
	       	  print(t[i])
     }' {} \; | \
     xargs -I {} xdg-mime default slopen.desktop {}

You may want to run this again after installing an application which introduces a new MIME type. So you may want to add it as your cron jobs, into /etc/rc.local or to some hooks in your distro's package manager, depending on your preference.