Is there a way to truncate field data

Question

I have some fields that are really long, but I just want to see the beginning of them. Is there a way to truncate a field to only the first X characters?

Answer 1

If you mean by trimming long strings, sure. Figure out which strings to trim then trim them.

e.g., trimming a string to the first 10 characters

$ echo '"12345678901234567890"' | jq '.[0:10]'

Read, take the first 0-10 characters of the string.

Answer 2

If you want to recursively trim all strings:

.. |= (if type == "string" then .[0:2] else . end)

For example, if the input is:

{"a": "aaaaaaaaaaaaaaaaaaaaaaaaaaaa", 
 "b": "bbbbbbbbbbbbbbbbbbbbbbbbbb",
 "c": ["ddddddddddddddd"]
}

the output (compacted) would be:

{"a":"aa","b":"bb","c":["dd"]}