Ability to show show/hide/shorten/widen JSON columns with hotkeys

[martinvonwittich]

Ability to show show/hide/shorten/widen JSON columns with hotkeys

[tstack]

First, I want to thank you for doing this writeup, that's a lot of work!

These JSON logs contain a lot of fields; many of these usually aren't important when examining the logs, so I've marked them as hidden in my format.

I think there's a technical limitation that prevents fields not in the line-format from being hidden since lnav needs to compute how many display lines a log message has. So, toggling them between being shown/hidden would change the number of lines that they take up and would require recomputing a bunch of stuff.

You should've been able to put the fields in the line-format and have them hidden by default, but there seems to be a bug there and they are shown. I'll fix that.

The access_log format would lend itself very well to strictly aligned columns, e.g. instead of this:

I think when I wrote the min-width stuff I wasn't keeping track of stats for the fields. But, now we are, so I can probably track the max length found for a field and add an option to default to that.

I would like to see the column headers so that I know which column is which.

I can experiment with this, there is already functionality to overlay column headers in the display.

I had hoped to display the numbers as e.g. "200 73r 169s 0.176", but instead the numbers are aligned to their width first, and only then are the characters affixed (73 r 169 s).

You can add "align": "right" to the value definition so that you get 73r. I should probably have the default for numbers to be right aligned anyhow...

A detail view that can show all fields, even those that are hidden, and without any shortening applied to the overview, might be useful.

Pressing p will display what the parser knows about a log message:

I'll get to looking into these changes soon, thanks again!