ObjectFile

File operation object, used for binary file reading and writing

The file operation object is used to operate binary files. You can usefsModule to open and create files:

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var f = fs.openFile('test.txt');

inheritance relationship

member properties

name

String, query the current file name

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readonly String File.name;

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fd

Integer, query the current file descriptor

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readonly Integer File.fd;

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Integer, queryStreamThe corresponding file descriptor value, implemented by subclasses

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readonly Integer File.fd;

member function

chmod

Query the access permissions of the current file. Windows does not support this method.

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File.chmod(Integer mode) async;

Call parameters:

• mode: Integer, specifies the set access permissions

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seek

Move the current file operation location

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File.seek(Long offset,
    Integer whence = fs.SEEK_SET);

Call parameters:

• offset: Long, specify the new location
• whence: Integer, specifies the position reference, allowed values ​​are: SEEK_SET, SEEK_CUR, SEEK_END

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tell

Query the current position of the stream

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Long File.tell();

Return results:

• Long, returns the current position of the stream

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rewind

Move the current position to the beginning of the stream

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File.rewind();

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size

Query stream size

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Long File.size();

Return results:

• Long, returns the stream size

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readAll

Read all remaining data from the stream

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Buffer File.readAll() async;

Return results:

• Buffer, returns the data read from the stream. If there is no data to read or the connection is interrupted, null is returned.

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truncate

Modify the file size. If the new size is smaller than the original size, the file will be truncated.

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File.truncate(Long bytes) async;

Call parameters:

• bytes: Long, new file size

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eof

Query whether the file reaches the end

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Boolean File.eof();

Return results:

• Boolean, returns True to indicate the end

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stat

Query basic information of the current file

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Stat File.stat() async;

Return results:

• Stat, returnStatObject description file information

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read

Read data of specified size from the stream

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Buffer File.read(Integer bytes = -1) async;

Call parameters:

• bytes: Integer, specifies the amount of data to be read. The default is to read data blocks of random size. The size of the data read depends on the device.

Return results:

• Buffer, returns the data read from the stream. If there is no data to read or the connection is interrupted, null is returned.

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write

Write the given data to the stream

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File.write(Buffer data) async;

Call parameters:

• data:Buffer, given the data to be written

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flush

Write file buffer contents to physical device

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File.flush() async;

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close

Close the current stream object

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File.close() async;

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copyTo

Copy stream data to target stream

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Long File.copyTo(Stream stm,
    Long bytes = -1) async;

Call parameters:

• stm:Stream, target stream object
• bytes: Long, number of bytes copied

Return results:

• Long, returns the number of bytes copied

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toString

Returns the string representation of the object. Generally, "[Native Object]" is returned. The object can be re-implemented according to its own characteristics.

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String File.toString();

Return results:

• String, returns the string representation of the object

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toJSON

Returns a JSON format representation of the object, generally returning a collection of readable properties defined by the object.

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Value File.toJSON(String key = "");

Call parameters:

• key: String, not used

Return results:

• Value, returns a value containing JSON serializable