node-fdleakcheck: check for file descriptor leaks

This Node module provides primitives for taking a snapshot of open file descriptors and comparing two snapshots to determine if there's been a file descriptor leak.

The implementation is specific to SunOS systems (including SmartOS, OmniOS, and Solaris), as it relies on proc(4) for correctness and pfiles(1M) for human-readable output.

This implementation also depends on child processes (ls, bash, and pfiles). It's possible to check for fd leaks without this, but not without observing the leak checker itself. This module opts for avoiding opening any files itself during the leak check.

Synopsis

var fdleakcheck = require('fdleakcheck');
var fdsBefore;
fdleakcheck.snapshot(function (err, snapshot) {
        if (err) {
                console.error('failed to check fd leaks: %s', err.message);
                return;
        }

        fdsBefore = snapshot;
        /* proceed with operation */
        /* ... */
        /* some time later, after operation */
        fdleakcheck.snapshot(function (err2, fdsAfter) {
                if (err2) {
                        console.error('failed to check fd leaks: %s',
                            err2.message);
                        return;
                }

                if (fdsBefore.differs(fdsAfter)) {
                        console.error('leaks found!');
                        console.error('fds open before:');
                        console.error(fdsBefore.openFdsAsString());
                        console.error('fds open after:');
                        console.error(fdsAfter.openFdsAsString());
                } else {
                        console.error('no leaks found');
                }
        });
});

Errors indicate problems creating the snapshot. Leaks are not turned into Errors. It's up to you to use differs to compare two snapshots to see if there's a leak.

Your program should not be doing anything with file descriptors while a snapshot() operation is oustanding. If it is, the results of the snapshot are undefined.

Contributions

Contributions welcome. Code should be "make prepush" clean. To run "make prepush", you'll need these tools:

• https://github.com/davepacheco/jsstyle
• https://github.com/davepacheco/javascriptlint

If you're changing something non-trivial or user-facing, you may want to submit an issue first.