options may also include a start option to allow writing data at some
position past the beginning of the file, allowed values are in the
[0, Number.MAX_SAFE_INTEGER] range. Modifying a file rather than
replacing it may require the flags option to be set to r+ rather than the
default w. The encoding can be any one of those accepted by Buffer.
If autoClose is set to true (default behavior) on 'error' or 'finish' the file descriptor will be closed automatically. If autoClose is false,
then the file descriptor won't be closed, even if there's an error.
It is the application's responsibility to close it and make sure there's no
file descriptor leak.
By default, the stream will emit a 'close' event after it has been
destroyed. Set the emitClose option to false to change this behavior.
By providing the fs option it is possible to override the corresponding fsimplementations for open, write, writev and close. Overriding write()without writev() can reduce
performance as some optimizations (_writev())
will be disabled. When providing the fs option, overrides for at least one ofwrite and writev are required. If no fd option is supplied, an override
for open is also required. If autoClose is true, an override for close is also required.
Like fs.ReadStream, if fd is specified, fs.WriteStream will ignore thepath argument and will use the specified file descriptor. This means that no'open' event will be
emitted. fd should be blocking; non-blocking fds
should be passed to net.Socket.
If options is a string, then it specifies the encoding.
options
may also include astart
option to allow writing data at some position past the beginning of the file, allowed values are in the [0,Number.MAX_SAFE_INTEGER
] range. Modifying a file rather than replacing it may require theflags
option to be set tor+
rather than the defaultw
. Theencoding
can be any one of those accepted byBuffer
.If
autoClose
is set to true (default behavior) on'error'
or'finish'
the file descriptor will be closed automatically. IfautoClose
is false, then the file descriptor won't be closed, even if there's an error. It is the application's responsibility to close it and make sure there's no file descriptor leak.By default, the stream will emit a
'close'
event after it has been destroyed. Set theemitClose
option tofalse
to change this behavior.By providing the
fs
option it is possible to override the correspondingfs
implementations foropen
,write
,writev
andclose
. Overridingwrite()
withoutwritev()
can reduce performance as some optimizations (_writev()
) will be disabled. When providing thefs
option, overrides for at least one ofwrite
andwritev
are required. If nofd
option is supplied, an override foropen
is also required. IfautoClose
istrue
, an override forclose
is also required.Like
fs.ReadStream
, iffd
is specified,fs.WriteStream
will ignore thepath
argument and will use the specified file descriptor. This means that no'open'
event will be emitted.fd
should be blocking; non-blockingfd
s should be passed tonet.Socket
.If
options
is a string, then it specifies the encoding.