A TUI JSON log viewer written in Go.
While working on the 2021 UChicago Trading Competition, I realized that it would be important to have verbose, meaningful logs that could be used to identify bugs/other strange behavior experienced by competitors. I settled on JSON logging as a good way to add lots of structure/metadata to these logs, but I found that most JSON log viewers were either graphical/messy or extremely minimal.
This viewer was made in order to allow for exploratory analysis of JSON logs under roughly 100k lines. It allows for relatively fast, human-readable filtering using antonmedv/expr, and strives to have sane behavior as much as possible.
To install,
$ go get -u github.com/quid256/jlvTo open a logfile for viewing,
$ jlv <file>The usage is listed in the below table because I'm too busy to make a help menu rn:
When in "normal mode" (the mode you will be in when actually exploring logs), the keys are as follows
| Key | Action |
|---|---|
| j, <down> | Scroll down in the log pane |
| k, <up> | Scroll up in the log pane |
| J | Page down in log pane |
| K | Page up in log pane |
| G | Scroll to bottom of log |
| g | Scroll to top of log |
| u | Scroll down in the JSON pane |
| i | Scroll up in JSON pane |
| h | Shrink log pane, grow JSON pane |
| l | Grow log pane, shrink JSON pane |
| /, : | Enter filter mode |
| Ctrl+C | Exit |
When in "filter mode", you can type a filter at the bottom of the screen. Press Esc to cancel or Enter to submit. The status of the filter is listed to the right:
- If the icon is a check, then the filter ran successfully and the results are being displayed in the log pane
- If the icon is an X, then the filter failed and the log is displayed with no filter applied
- If the icon is a ?, then the filter text at the bottom does not accurately represent the applied filter (happens when you Esc while writing a filter) or there is no filter applied at all.
- Odd behavior when filtering on a field that doesn't necessarily exist in the structure
- Nord color scheme (not sure how to change it to match terminal scheme with TCell)
- Takes some time to load odd files (maybe some form of lazy loading could be used?)