Process substitution - Node.js child_process

Question

Process substitution - Node.js child_process

I'm trying to run a child process to modify a file (in two steps) before reading the modified content from stdout. I'm trying to do this by using process substitution which works perfectly in bash but not when i try it from node.

This is kind of, what the command looks like..

var p = exec('command2 <(capture /dev/stdout | command1 -i file -) -',
function (error, stdout, stderr) {
   console.log(stderr);
});

stderr prints:

/bin/sh: -c: line 0: syntax error near unexpected token `('

What is the proper way of doing this in node?

node.js
bash
pipe
child-process
process-substitution

Answer 1

I solved this by putting the commands in a shell script and calling the script from the node child process. I also needed to add the following to set bash in posix mode to allow process substitution:

set +o posix

There is probably a nicer way of doing this directly from within node but it did the job. Cheers!

Answer 2

you can have bash evaluate a command with bash -c 'command'. I've tested this and it works with process substitution and child_process.