Passing variables to curl command in child_process.exec fails - node.js

Question

I was trying to use child_process.exec to call curl with a long command in order to send some data to an API. Something similar to the following example:
exec('git log --oneline | wc -l', function(error, stdin, stderr) {
if (stdin > 1) {
exec('curl -H "Content-Type: application/json" -X POST -d \'{"value1": "\'"$arg"\'"}\' https://https://maker.ifttt.com/trigger/{event}/with/key/<my-key>', { "env" : {"arg": stdin } });
}
})
So if a git repo includes more than one line in its git log output, then you execute a POST request to some API (here, a simple webhook in ifttt.com), in which you're passing some variable (arg) in the process.
Notice that this is the best attempt, but in general, I was struggling quite a bit to escape single and double quotes. In this particular case, the HTTP request was not sent correctly because the body includes a line break:
POST / HTTP/1.1
Host: <some-host>
User-Agent: curl/7.50.1
Accept: */*
Content-Type: application/json
Content-Length: 16
{"value1": "2
"}
At the end, I had to use an external bash script:
exec('./send_request.sh $arg', { "env": {"arg": stdin } });
but I'm still very curious on how to make it work within the same js file.
If it helps, I'm running node 6.11.0 and curl 7.52.1.

Answer 1

Try:
exec('git log --oneline | wc -l', function(error, stdin, stderr) {
if (stdin > 1) {
exec('curl -H "Content-Type: application/json" -X POST -d \'{"value1": "\'"$arg"\'"}\' https://https://maker.ifttt.com/trigger/{event}/with/key/<my-key>', { "env" : {"arg": stdin.replace(/\n/g, '') } });
}
})
What is happening is that your variable 'stdin' (you should rename it to 'stdout') has a \n at the end of it.