watch
Watch for changes on filename
, where filename
is either a file or a directory.
The second argument is optional. If options
is provided as a string, it specifies the encoding
. Otherwise options
should be passed as an object.
The listener callback gets two arguments (eventType, filename)
. eventType
is either 'rename'
or 'change'
, and filename
is the name of the file which triggered the event.
On most platforms, 'rename'
is emitted whenever a filename appears or disappears in the directory.
The listener callback is attached to the 'change'
event fired by fs.FSWatcher
, but it is not the same thing as the 'change'
value of eventType
.
If a signal
is passed, aborting the corresponding AbortController will close the returned fs.FSWatcher
.
Since
v0.5.10
Parameters
Watch for changes on filename
, where filename
is either a file or a directory, returning an FSWatcher
.
Parameters
A path to a file or directory. If a URL is provided, it must use the file:
protocol.
Either the encoding for the filename provided to the listener, or an object optionally specifying encoding, persistent, and recursive options. If encoding
is not supplied, the default of 'utf8'
is used. If persistent
is not supplied, the default of true
is used. If recursive
is not supplied, the default of false
is used.
Watch for changes on filename
, where filename
is either a file or a directory, returning an FSWatcher
.
Parameters
A path to a file or directory. If a URL is provided, it must use the file:
protocol.
Returns an async iterator that watches for changes on filename
, where filename
is either a file or a directory.
const { watch } = require('node:fs/promises');
const ac = new AbortController();
const { signal } = ac;
setTimeout(() => ac.abort(), 10000);
(async () => {
try {
const watcher = watch(__filename, { signal });
for await (const event of watcher)
console.log(event);
} catch (err) {
if (err.name === 'AbortError')
return;
throw err;
}
})();
On most platforms, 'rename'
is emitted whenever a filename appears or disappears in the directory.
All the caveats
for fs.watch()
also apply to fsPromises.watch()
.
Since
v15.9.0, v14.18.0
Return
of objects with the properties: