jq not writing value of variable but the actual text of the variable name

November 11, 2021

I’m scripting in bash to edit a json template to replace some field values with arguments to my script, and trying to use jq to do the editing. My code is not replacing the –arg with the value of the argument, but the literal text of the argument name.

My template contains:

{
"name":""
}

My jq code:

jq --arg ad "192.168.5.5" -r '.name = "Addr $ad"' address.tmpl

This outputs:

{
    "name": "Addr $ad"
}

Or, if I remove the double-quotes

jq --arg ad "192.168.5.5" -r '.name = Addr $ad' address.tmpl

I get

jq: error: syntax error, unexpected '$', expecting $end (Unix shell quoting issues?) at <top-level>, line 1:
.name = Addr $ad
jq: 1 compile error

According to all that I have read, this should work. What am I doing wrong/how do I fix this????

OS = debian 10

>Solution :

jq --arg ad "192.168.5.5" -r '.name = "Addr " + $ad' address.tmpl

It must be hardquoted for the shell (to stop shell expansion), and not quoted for jq. Edit: unless it is escaped, like \($ad). Use whichever you find more readable.