graceful-fs functions as a drop-in replacement for the fs module, making various improvements.
The improvements are meant to normalize behavior across different platforms and environments, and to make filesystem access more resilient to errors.
- Queues up
readdircalls, and retries them once something closes if there is an EMFILE error from too many file descriptors.
lchmodfor Node versions prior to 0.6.2.
fs.lutimesif possible. Otherwise it becomes a noop.
lchownif the user isn't root.
lchownbecome noops, if not available.
- retries reading a file if
readresults in EAGAIN error.
On Windows, it retries renaming a file for up to one second if
EPERM error occurs, likely because antivirus software has locked
// use just like fs var fs = require('graceful-fs') // now go and do stuff with it... fs.readFileSync('some-file-or-whatever')
If you want to patch the global fs module (or any other fs-like module) you can do this:
// Make sure to read the caveat below. var realFs = require('fs') var gracefulFs = require('graceful-fs') gracefulFs.gracefulify(realFs)
This should only ever be done at the top-level application layer, in order to delay on EMFILE errors from any fs-using dependencies. You should not do this in a library, because it can cause unexpected delays in other parts of the program.