jq is the program to manipulate JSON in Bash. The most common use is to pull some information out of JSON files. It uses a filter language to manipulate the input. The simplest filter is the identity, . (a single full stop). This is similar to mathematical identity: the input becomes the output. Let’s create a file containing some non–trivial JSON and apply the identity filter to it:

$ cat > ./credentials.json << 'EOF'

> {"username":"jdoe","password":"sec\\ret$"}

> EOF

$ jq . ./credentials.json

{

  "username": "jdoe",

  "password": "sec\\ret$"

}

The first command uses a quoted here document to save a string with special characters without having to escape them.