# jello > A command-line JSON processor using Python syntax. > More information: . - Pretty-print JSON or JSON-Lines data from `stdin` to `stdout`: `cat {{file.json}} | jello` - Output a schema of JSON or JSON Lines data from `stdin` to `stdout` (useful for grep): `cat {{file.json}} | jello -s` - Output all elements from arrays (or all the values from objects) in JSON or JSON-Lines data from `stdin` to `stdout`: `cat {{file.json}} | jello -l` - Output the first element in JSON or JSON-Lines data from `stdin` to `stdout`: `cat {{file.json}} | jello _[0]` - Output the value of a given key of each element in JSON or JSON-Lines data from `stdin` to `stdout`: `cat {{file.json}} | jello '[i.{{key_name}} for i in _]'` - Output the value of multiple keys as a new JSON object (assuming the input JSON has the keys `key_name` and `other_key_name`): `cat {{file.json}} | jello '{"{{my_new_key}}": _.{{key_name}}, "{{my_other_key}}": _.{{other_key_name}}}'` - Output the value of a given key to a string (and disable JSON output): `cat {{file.json}} | jello -r '"{{some text}}: " + _.{{key_name}}'`