Odtnhj

How can I run a bash command for every json object in a json array using jq? So far I have this:

cat credentials.json | jq -r '. | .user, .date, .email' | mycommand -u user -d date -e email

This doesn't seem to work. How can I take the parameters out of the json array into my command?

My json file looks something like this:

[
 "user": "danielrvt",
 "date": "11/10/1988",
 "email": "myemail@domain.com",
 ...
]

Your best bet is probably to output each record in something like TSV format, then read that from a shell loop.

jq -r '.|[.user, .date, .email] | @tsv' |
 while IFS=$'t' read -r user date email; do
 mycommand -u "$user" -d "$date" -e "$email"
 done

jq itself doesn't have anything like a system call to run an external command from within a filter, although it seems that they are working on it.

You could have jq output the commands to execute, something like

. | "mycommand (.user|@sh) (.date|@sh) (.email|@sh)"

Then execute it. Something like

bash <(jq -r '. | "mycommand (.user|@sh) (.date|@sh) (.email|@sh)"' foo)

With xargs:

curl localhost:8082/connectors | jq . | xargs -L1 -I'' curl -XDELETE 'localhost:8082/connectors/' 

Or equivalently, to show the output of that first curl:

echo '["quickstart-file-sink4","quickstart-file-source","quickstart-file-sink","quickstart-file-sink2","quickstart-file-sink3","quickstart-file-source2"]' | jq . | xargs -L1 -I'' curl -XDELETE 'localhost:8082/connectors/' 

jq . strips off one level of containment, so that a list becomes output as one line per item.

xargs -L1 processes one line at a time

xargs -I'' specifies that the string be replaced with the input line when invoking the following command.

xargs is essentially a map operator for the shell.

I came across the same problem recently where xargs doesn't help that much due to the relatively complicated set of arguments I wanted to pass around. Thus I implemented an sh filter (and its friends) to jq. I haven't yet had enough time to write documentation and tests for it so not creating a PR for it to become a part of the official codebase yet. So now it's only for the ones who are willing to compile this version themselves:

https://github.com/haochenx/jq/tree/sh-support