Taskwarrior: [TW-1745] Allow for use of environment variables in config file

[taskwarrior]

_Alan Young on 2015-12-30T17:20:56Z says:_

The specific example I want to use is, in the .taskrc file:

include data.location/include/file_to.include

where data.location is replaced with the value of the config option data.location.

[taskwarrior]

Migrated metadata:

Created: 2015-12-30T17:20:56Z
Modified: 2017-01-16T18:29:11Z

[taskwarrior]

_Paul Beckingham on 2017-01-16T18:29:11Z says:_

Change title to add 'environment' which might be more useful.

[dsifford]

Just adding some comments related to what the last guy (directly above me) said:

Simply "using" or reading environment variables in .taskrc is also something I'd be interested in...

Specific use-case:

I have TASKRC in my environment pointed to "$XDG_CONFIG_HOME"/taskrc and inside my taskrc I would like to set data.location to "$XDG_DATA_HOME/task".

[Neurognostic]

Another use case: I would like to be able to read environment variables for configuring certificate, key, and ca paths for taskd syncing.

Example, as of version 2.5.1, this does not currently work:

taskd.certificate=$XDG_DATA_HOME/task/taskd.cert.pem
taskd.key=$XDG_DATA_HOME/task/taskd.key.pem
taskd.ca=$XDG_DATA_HOME/task/taskd.ca.pem

But taskwarrior does understand ~ means $HOME so as a workaround this does work:

taskd.certificate=~/.local/share/task/taskd.cert.pem
taskd.key=~/.local/share/task/taskd.key.pem
taskd.ca=~/.local/share/task/taskd.ca.pem