Implement option length selection with options and environment variables

[Managor]

Initial ideas on how to implement the shortform/longform print modes.

[Managor]

Related issue tldr-pages/tldr#13556

[sbrl]

Seems interesting. Does this always hold up with all instances of {{a|b}} where {{-a|--b}}?

What would you envision the CLI to look like for tldr? Could you disable the short/longform parsing support and display everything at all? What would the default be?

[acuteenvy]

What about tools that don't follow this convention for short and long options (e.g. tldr-pages/tldr#13556 (comment))?
I don't think there's a way to fully support option selection without introducing special syntax as discussed in tldr-pages/tldr#5092.

[Managor]

If a tool doesn't follow this convention then it won't be affected by this. Simple as that.

[acuteenvy]

This regular expression won't work if there are multiple short options in a single placeholder.
Example:
https://github.com/tldr-pages/tldr/blob/3823ba7fc64e2c368e87950f1aaf407d88f6957f/pages/common/rsync.md#L17

`rsync {{-zvhP|--compress --verbose --human-readable --partial --progress}} {{path/to/source}} {{path/to/destination}}`

[Managor]

That is by design. Like I said in the original issue, the initial implementation should be as strict as possible.

EDIT: However. That example is pretty nice for condensing the shortform options. Maybe I should allow it to be picked up.

[Managor]

Alright, I'm looking for feedback again. Is this the proper way to implement options? Also how can I implement TLDR_SHORTFORM and TLDR_LONGFORM env variables?

[Managor]

Nvm figured it out. Now I'm just looking for feedback.

[Managor]

I adjusted the client specs in tldr-pages/tldr#15253 and adjusted the code to match it. I'm looking for feedback.

[Managor]

Demonstrative images
Input:

tldr rsync

tldr -S rsync

tldr -V rsync

tldr -VS rsync

[Managor]

grep -rE "{{\[.*\|.*\]}}" shows no matches. Accidental usages of this pattern should not be found.

[Managor]

@kbdharun You seem to be fluent in manpage language. Would you be willing to make an addition to the tldr manpage after this goes through?

[kbdharun]

@kbdharun You seem to be fluent in manpage language. Would you be willing to make an addition to the tldr manpage after this goes through?

Sure

[Managor]

Updated tldr -VS rsync

[Managor]

I implemented the final command line options seen in the release. I'm looking for feedback again.

[Managor]

@sebastiaanspeck I would like to write tests for option placeholders. Do you have any tips the process and where to start?
I would like to test with only environment variables, only options, mixed environment variables and options and finally garbled environment variable contents.

[sebastiaanspeck]

@sebastiaanspeck I would like to write tests for option placeholders. Do you have any tips the process and where to start?

I would like to test with only environment variables, only options, mixed environment variables and options and finally garbled environment variable contents.

This Python script has some tests https://github.com/tldr-pages/tldr/blob/main/scripts/_common.py

[Managor]

Lets merge this. I tested manually that this works. I might write tests in a separate PR. Requesting reviews.

[kbdharun]

LGTM, thanks for the additions. Tested the changes locally and it works as expected. As promised before, will update the man page once the PR gets merged.

Adding screenshots for future reference:

Default Behaviour	With short option flag passed