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hoshsadiq | 4 years ago

I tend to use jq a lot. As others have said, sometimes jq can be hard to grasp. Often it requires multiple attempts to get the correct answer. To make it a little easier for me, I've written a helper function[0] that combines it with fzf[1] to run jq as a REPL on any json. It allows to incrementally alter your DSL without having to continually call jq. This is similar to jid/jiq but a little more powerful. It includes functions to change the preview to output raw, compact (or not), and some other things.

It is essentially similar to jqplay but local.

I didn't use jid/jiq because jid uses go-simplejson, which is nowhere near as powerful as jq, and jiq seemed very buggy when I used it and it felt like it was hacked together. Plus there was no where to change jq's arguments while running it.

I'm sure this function can be improved on, but this has been good enough for me so far.

Also, I run gojq[2] instead of jq. It is a drop-in replacement for jq but is written in Go, and has some improvements over jq such as bug fixes, support for yaml input, and it also provides more helpful error messages.

[0] https://github.com/hoshsadiq/dot_files/blob/master/zshrc.d/m...

[1] https://github.com/junegunn/fzf

[2] https://github.com/itchyny/gojq/

discuss

order

fisxoj|4 years ago

If anyone is an emacs user and this sounds compelling, I recommend counsel-jq[0] for the sort of feedback loop described here.

[0]: https://github.com/200ok-ch/counsel-jq

forty|4 years ago

I use counsel-jq occasionally, and my main issue with it is the single line input. As soon as the filtering is not trivial, it's much more convenient to be able to use multiple lines.

psacawa|4 years ago

I've written about this before, but for tmux users, I have interactive querying the form of ten-line shell script [1]. See it live [2]. It can easily be modfied to interactively query yaml, html with xpath or css, or text with awk or what have, and I have variants for each of these. This has the advantage over the parent comment thatyou have your text editor's key bindings instead of those of fzf.

Dependencies: tmux, nodemon, less, jq, vim

[1]: https://gist.github.com/psacawa/e63c4e25a8b0405309d3a03b6b50...

[2]: https://streamable.com/jwdrqu

kbd|4 years ago

Just sharing my take on that interactive jq (or anything else) repl:

https://github.com/kbd/setup/blob/master/HOME/bin/fzr

It's just an fzf wrapper that sets up temporary files and so on. It works really well; it's amazing all the things one can use fzf for.

ossusermivami|4 years ago

This is nice, it uses latest/modern python3 features, thanks, I needed some use case to see how those feature are useful in real world...

alerighi|4 years ago

I'm the opposite, I find that jq doesn't have a reason to exist, other than pretty printing JSON files on a terminal and doing basic filtering on a JSON object and only as interactive shell usage, NOT in a script.

It's the classical tool, like sed, like awk, like a ton of unix utility that at first they seem to you easy to use, then you have to do something complex and you start abusing them, by piping things multiple times into jq, and you end up writing things like this:

    echo $json | jq "something $(echo $variable | jq 'something else' | tr '"' '\'') | sed 's/"/\\'/g" | jq "another js invocation" | awk '...' > file2.json
I stopped using jq after realizing that I was wasting my time by trying to fix a script that used jq and didn't managed quoting correctly, trying to use different kind of quotes, even filtering the input before passing it to jq with tr replacing things. It's just another tool prone to abuse like sed, awk, tr, cut or similar things.

I thought why I'm wasting my time on a tool that has a complex and limited DSL when I can write a clean python script in 10 minutes to do the same things that is easier to write, to read and most importantly to maintain.

To me a script that has to manipulate JSON should be written in an high level programming language like Python, and not be abused with tool as jq and stuff. Even I there is an already existent big bash script that you don't want to rewrite and you have to do some json processing in it... you can write an inline python script like this:

     python3 <<PYEND
     ## your python code
     PYEND
Also jq is another dependency to a script that must be installed.

ris|4 years ago

Speaking as a long-time python developer...

If you actually "get into" jq you find out that it's a significantly neater language than it appears on the surface. Firstly it does allow you write multi-line scripts, and things start to look a lot neater once you do. Secondly it's actually a real, working, functional programming language, which allows very succinct expression of ideas which, in python, would likely require the reader to track state across explicit loops and the like.

Once you dig into the manual, you also tend to discover that a lot of the things that cause you to string multiple jq invocations together aren't actually necessary because there are quite sensible ways of handling them in-language.

It's quite laughable though to tout python over jq because of it adding a dependency. Perhaps if you're already embedded in python-land and all your environments already have python - but many (most?) of us are increasingly targeting extremely minimal container image environments. In that case, adding python is a much larger and more complex dependency than jq's single 3.8MB binary.

As someone who has to read an awful lot of other peoples deployment scripts, it's also quite nice when I see jq because it loudly advertises "all I'm doing here is mangling one piece of json into another! no side effects!". I'd much rather follow the thread of execution into that than some mystery ruby script any day.

Arnavion|4 years ago

If you have quoting issues, and going by the example you posted of replacing quotes with sed and tr, you haven't learned how to pass parameters to jq correctly. You should use `--arg` and `--argjson`, not shell string interpolation, to pass in external strings / JSON object strings to your jq command. And use `--raw-output` to convert JSON strings to displayable strings (ie no quotes, evaluated escapes) for output.

philsnow|4 years ago

I do the same thing (want to iterate on some complicated jq query -- or, let's be real, blunder around with my loose grasp of jq). I use https://github.com/lotabout/skim#interactive-mode instead of fzf.

  function jqsk {
    sk --tac --ansi --regex  --query . --multi --interactive --cmd '{}' \
       --bind 'enter:select-all+accept,ctrl-y:select-all+execute-silent(for line in {+}; do echo $line; done | pbcopy)+deselect-all' \
       --cmd-history=${HOME}/.sk_history --cmd-history-size=100000 \
       --no-clear-if-empty \
       --cmd-query "cat $1 | jq --raw-output --color-output --exit-status '.'"
  }
I run it like `jqsk file.json` and then change the `'.'` in the cmd-query to whatever I'm trying to do with jq.

I'll definitely look into some of the other mentioned solutions for this though. I settled on skim a year+ ago and haven't revisited.

rodorgas|4 years ago

That’s cool! What’s the use of FZF? Isn’t it a fuzzy finder, what are you searching for in a jq REPL?

hoshsadiq|4 years ago

It only uses the FZF's preview. The suggestions is completely empty. I tried to find an alternative as FZF has no way of disabling the selector window, but I was unable to find anything that was good enough for this.

I considered forking jid/jiq and using gojq as a library, but I ended up not going down that route because of reasons that I cannot remember. I also considered using a tui or something but FZF has so much already implemented and has a lot of it right, and I didn't particularly feel like re-inventing the wheel.

rattray|4 years ago

This looks cool - would you be willing to share it in a brew-installable format?

hoshsadiq|4 years ago

Not particularly. I don't use a Mac, but I'd be happy to separate out the function into it's own script so it can be downloaded and put in your $PATH. I personally use zinit to manage individual files from random repos.

alex_smart|4 years ago

Why not just use inotify (or similar tools offered by other OS)?