Is there a way to list all configurable `alternatives` (symlinks for similar commands) on the system?

Solution 1:

On Debian (but not Fedora or RHEL), to see a list of all "master alternative names":

update-alternatives --get-selections

--get-selections list master alternative names and their status.

And for each of those listed, you can run --list $ALTERNATIVE_NAME, e.g.

update-alternatives --list editor

--list name Display all targets of the link group.

If you would like to see a list of all alternatives in their respective groups, you could run the following in fish shell:

for alternative in (update-alternatives --get-selections)
    echo $alternative 
    update-alternatives --list (echo $alternative | cut -d" " -f1)
end | pager

The (ba|z)?sh syntax should be something similar.

To change the alternatives, run sudo update-alternatives --config $ALTERNATIVE_NAME

Solution 2:

The exact answer is (RHEL):

ls /var/lib/alternatives

Directory /etc/alternatives maintains flat long list of all symlinks mixing masters and slaves together. Slave symlinks cannot be used with alternatives --display [symlink] command.

At the same time directory /var/lib/alternatives contains status information (including master-slave relationship) for each group in shortened list of file names all of which can be directly used with --display option. For example, /var/lib/alternatives/java:

alternatives --display java

Solution 3:

The simplest answer would be...

ls /etc/alternatives