The horror of quoting on the command line

July 7, 2021

While I am usually very pro-JMESPath and pro-JQ, they can sometimes be a real pain, and this post serves no other purpose than to exemplify this.

I just spent close to three hours trying to get a simple query working and I’m not even happy I got it working after spending so much time on it…

Here’s a sample of the data I was working on just in case you want to practice masochism as well:

[
    {
        "name": "resource1",
        "tags": {
            "currently-used": "False"
        }
    },
    {
        "name": "resource2",
        "tags": {
            "currently-used": "False"
        }
    },
    {
        "name": "resource3",
        "tags": {
            "currently-used": "True"
        }
    },
    {
        "name": "resource4",
        "tags": {
            "currently_used": "False"
        }
    }
]

Feed that into the JMESPath website and try to get the names of the resources whose tag ‘currently-used’ OR ‘currently_used’ (note the hyphen and underscore) is set to the string ‘False’ (the value itself does not contain quotes).

Got it? Great! It took me a heck of a lot more time than I initially expected because I was adding quotes around the names of the tags. That is required when you’re working on the command line, even though I wasn’t… The following will work on the website:

[?tags.currently-used == 'False' || tags.currently_used == 'False'].name

Now, I knew I definitely needed to add quotes around the names of the tags when moving over to the command line, but I didn’t want to do a bunch of unnecessary queries against Azure, so I turned to jpterm. I thought that if I got it working there then it would just be directly applicable for my ultimate usage with Azure CLI. How foolish of me. This query will yield the same result in jpterm

[?tags."currently-used" == 'False' || tags."currently_used" == 'False'].name

So, now it’s working in something that’s close to the actual implementation that Azure CLI will use. Should be smooth sailing from here on out, but after many failed attempts where I was returned both True and False:

"[?tags.\"currently-used\" == "False" || tags.\"currently_used\" == "False"].name"
"[?tags.\"currently-used\" == "False" || tags.currently_used == "False"].name"
"[?tags.\"currently-used\" == \"False\" || tags.\"currently_used\" == \"False\"].name"
'[?tags."currently-used" == 'False' || tags."currently_used" == 'False'].name'

And shown straight-up errors:

$ az resource list --query "[?tags."currently-used" == 'False' || tags."currently_used" == 'False'].name"
argument --query: invalid jmespath_type value: "[?tags.currently-used == 'False' || tags.currently_used == 'False'].name"

I finally stumbled on the correct incantation:

"[?tags.\"currently-used\" == 'False' || tags.\"currently_used\" == 'False'].name"

In my defense sections labeled Important shouldn’t be way down in the official documentation…