Make CLI automatically switch from aligned to vertical format

[nineinchnick]

Description

Make CLI automatically switch from aligned to vertical format when the output wouldn't fit the current terminal's width. Currently, users can terminate the query with \G, but this has a few drawbacks:

• users need to run the query twice if they notice it's too wide
• a table that's too wide will be opened in the pager and won't remain on the screen when writing a follow-up query - users might want to refer to the values from the first query, so they'd need to interrupt writing the second one
• users have to notice the output is too wide - check out the output of SHOW FUNCTIONS where the second column is so wide you might not notice there are more
• it's kinda hard to type - backslash is unusual and G has to be upper-case

This PR introduces a new AUTO output format that automatically switches from ALIGNED to VERTICAL if the aligned table is wider than the current terminal. But it doesn't make the auto format the default, for backward compatibility. Users need to enable it by using --output-format-interactive=AUTO or by adding it to the config file.

Is this change a fix, improvement, new feature, refactoring, or other?

improvement

Is this a change to the core query engine, a connector, client library, or the SPI interfaces? (be specific)

cli

How would you describe this change to a non-technical end user or system administrator?

Add a new AUTO output format to the CLI client, that switches from ALIGNED to VERTICAL if the output wouldn't fit the current terminal.

Related issues, pull requests, and links

Documentation

( ) No documentation is needed.
(x) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

( ) No release notes entries required.
(x) Release notes entries required with the following suggested text:

# CLI
* Add a new `AUTO` output format, that switches from `ALIGNED` to `VERTICAL` if the output wouldn't fit the current terminal.  ({issue}`issuenumber`)

[nineinchnick]

This is the equivalent of \x auto in psql. Setting the env var is the equivalent of adding \x auto to ~/.psqlrc.

[hashhar]

The feature and implementation seems good to me.

The env var seems overkill to me. What use-case did you have in mind?

[nineinchnick]

The feature and implementation seems good to me.

The env var seems overkill to me. What use-case did you have in mind?

It's required so that users (well, I mostly ;-) can have it turned on by default, without changing the current default output (aligned). There's no RC file like in PostgreSQL. Without this, it defeats the purpose of it being automatic if I'd have to remember to turn it on on every invocation.

[hashhar]

Let's discuss about having a config file then, it seems like a good change IMO since it'll make it much easier to support things like not having to enter lengthy arguments for Kerberos or self-signed tls auth etc. as well instead of just being specific to this single feature.

cc: @electrum @findepi WDYT about a config file to read some defaults for configs from? Would make using the CLI a lot easier.

[nineinchnick]

@hashhar would it be enough to read a properties file from the user's home dir? https://picocli.info/#_propertiesdefaultprovider

[nineinchnick]

All done, I added reading a config file as the first commit. I also added two new options for the pager and history file, so they also can be configured via the file, not only as environmental variables, for consistency.

The second commit adds the new AUTO format but also allows to configure the output format in the interactive mode. @mosabua I requested a review from you because I made doc changes but let's first wait to get the code changes approved.

[nineinchnick]

@hashhar I removed the new env var for output format but changing the default in the config file means it'll apply to both interactive and batch modes. I'm thinking about adding yet another flag for interactive mode, but --output-format-interactive is a bit too long. Maybe a boolean --auto-expand to be used instead of adding a new output format?

[nineinchnick]

@hashhar @electrum @findepi this is ready for review.

[mosabua]

Docs look good now.

[nineinchnick]

@dain maybe you'd like to review this one?

[mosabua]

Could we get this reviewed by whoever necessary and merged?

[hashhar]

@electrum can you PTAL?

[nineinchnick]

@electrum @dain PTAL. Are features like this worth adding to the CLI? If not, I don't mind closing this PR.

[mosabua]

I think this is a good feature to add.

[nineinchnick]

@kokosing WDYT?

[kokosing]

I like this change. I think it is also safe to merge as it does not change any existing functionality, but adds new one.

[nineinchnick]

@kokosing this is ready to go, PTAL.

[aakashnand]

@nineinchnick I also think this is useful. I have faced this problem where there are too many columns, until now I have been using \G but this flag now looks promising. Good Job 👍🏼

[kokosing]

Thanks