Modify a key-value in a json using jq

Question

I have a json in which I want to modify a particular value but the terminal always displays the json with the modified value but it does not actually change the value in the particular file. Sample json:

{
   name: 'abcd',
   age: 30,
   address: 'abc'
}

I want to change the value of address in the file itself but so far I've been unable to do so. I tried using:

jq '.address = "abcde"' test.json

but it didn't work. Any suggestions?

Answer 1

Use a temporary file; it's what any program that claims to do in-place editing is doing.

tmp=$(mktemp)
jq '.address = "abcde"' test.json > "$tmp" && mv "$tmp" test.json

Answer 2

AFAIK jq does not support in-place editing, so you must redirect to a temporary file first and then replace your original file with it, or use sponge utility from the moreutils package, like that:

jq '.address = "abcde"' test.json|sponge test.json

There are other techniques to "redirect to the same file", like saving your output in a variable e.t.c. "Unix & Linux StackExchange" is a good place to start, if you want to learn more about this.