doc: improve fs.open() docs

This commit is contained in:
Ben Noordhuis 2012-05-17 06:18:25 +02:00
parent ccc4e547ea
commit 18b94ea838

View File

@ -270,16 +270,18 @@ An exception occurs if the file does not exist.
* `'r+'` - Open file for reading and writing. * `'r+'` - Open file for reading and writing.
An exception occurs if the file does not exist. An exception occurs if the file does not exist.
* `'rs'` - Open file for reading, telling the OS to open it synchronously * `'rs'` - Open file for reading in synchronous mode. Instructs the operating
(ie using the O_SYNC flag). Whilst rarely useful, when used with caution by system to bypass the local file system cache.
those who know what they're doing it can be sometimes necessary. Note that
this doesn't turn `fs.open()` into a synchronous blocking call, if that's what This is primarily useful for opening files on NFS mounts as it allows you to
you want then you should be using `fs.openSync()` skip the potentially stale local cache. It has a very real impact on I/O
An exception occurs if the file does not exist. performance so don't use this mode unless you need it.
Note that this doesn't turn `fs.open()` into a synchronous blocking call.
If that's what you want then you should be using `fs.openSync()`
* `'rs+'` - Open file for reading and writing, telling the OS to open it * `'rs+'` - Open file for reading and writing, telling the OS to open it
synchronously. synchronously. See notes for `'rs'` about using this with caution.
See notes for `'rs'` about using this with caution.
* `'w'` - Open file for writing. * `'w'` - Open file for writing.
The file is created (if it does not exist) or truncated (if it exists). The file is created (if it does not exist) or truncated (if it exists).