Use jq to turn x=y pairs into key/value pairs

Question

I\'m trying to parse environment variables from the JSON output of docker inspect. Annoyingly, those environment variables aren\'t returned as useful key-value

Answer 1

To convert an array of two strings (e.g. ["k", "v"]) to an object, you can write:

{ (.[0]) : .[1] }

So you'll want to write something like:

 map(.Config.Env |= (map( split("=") | { (.[0]) : .[1] } ) | add))

a2o

Abstracting out the array-to-object functionality makes the solution a bit more digestible:

def a2o: map( split("=") | { (.[0]) : .[1] } ) | add;

map(.Config.Env |= a2o)

Using match or capture instead of split

Since it is possible for an "=" character to appear in the "value" part of each var=value string, using split naively might not be such a great idea. Here is a more robust alternative, assuming your jq supports regular expressions:

match("([^=]*)=(.*)") | .captures | {(.[0].string) : .[1].string}

Or, slightly more succinctly and perhaps elegantly:

[capture( "(?[^:]*):(?.*)" )] | from_entries

index/1

If your jq does not have regex support, you could use index/1, along these lines:

index("=") as $ix | {(.[:$ix]) : .[$ix+1:]}