Queues up open and readdir calls, and retries them once
something closes if there is an EMFILE error from too many file
fixes lchmod for Node versions prior to 0.6.2.
implements fs.lutimes if possible. Otherwise it becomes a noop.
ignores EINVAL and EPERM errors in chown, fchown or
lchown if the user isn't root.
makes lchmod and lchown become noops, if not available.
retries reading a file if read results in EAGAIN error.
On Windows, it retries renaming a file for up to one second if EACCESS
or EPERM error occurs, likely because antivirus software has locked
// use just like fs
var fs = require('graceful-fs')
// nowgoanddostuffwith it...
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')
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.
This module is fairly stable at this point, and used by a lot of
things. That being said, because it implements a subtle behavior
change in a core part of the node API, even modest changes can be
extremely breaking, and the versioning is thus biased towards
bumping the major when in doubt.
The main change between major versions has been switching between
providing a fully-patched fs module vs monkey-patching the node core
builtin, and the approach by which a non-monkey-patched fs was
The goal is to trade EMFILE errors for slower fs operations. So, if
you try to open a zillion files, rather than crashing, open
operations will be queued up and wait for something else to close.
There are advantages to each approach. Monkey-patching the fs means
that no EMFILE errors can possibly occur anywhere in your
application, because everything is using the same core fs module,
which is patched. However, it can also obviously cause undesirable
side-effects, especially if the module is loaded multiple times.
Implementing a separate-but-identical patched fs module is more
surgical (and doesn't run the risk of patching multiple times), but
also imposes the challenge of keeping in sync with the core module.
The current approach loads the fs module, and then creates a
lookalike object that has all the same methods, except a few that are
patched. It is safe to use in all versions of Node from 0.8 through
Do not monkey-patch the fs module. This module may now be used as a
drop-in dep, and users can opt into monkey-patching the fs builtin
if their app requires it.
Monkey-patch fs, because the eval approach no longer works on recent
fixed possible type-error throw if rename fails on windows
verify that we never get EMFILE errors
Ignore ENOSYS from chmod/chown
clarify that graceful-fs must be used as a drop-in
Use eval rather than monkey-patching fs.
readdir: Always sort the results
win32: requeue a file if error has an OK status
A return to monkey patching
Don't clobber the fs builtin
Handle fs.read EAGAIN errors by trying again
Expose the curOpen counter
No-op lchown/lchmod if not implemented
fs.rename patch only for win32
Patch fs.rename to handle AV software on Windows
Close #4 Chown should not fail on einval or eperm if non-root
Fix isaacs/fstream#1 Only wrap fs one time
Fix #3 Start at 1024 max files, then back off on EMFILE
lutimes that doens't blow up on Linux
A full on-rewrite using a queue instead of just swallowing the EMFILE error