Instance Method


Writes the contents of the receiver to a file at a given path using a given encoding.


func write(toFile path: String, atomically useAuxiliaryFile: Bool, encoding enc: UInt) throws



The file to which to write the receiver. If path contains a tilde (~) character, you must expand it with expandingTildeInPath before invoking this method.


If true, the receiver is written to an auxiliary file, and then the auxiliary file is renamed to path. If false, the receiver is written directly to path. The true option guarantees that path, if it exists at all, won’t be corrupted even if the system should crash during writing.


The encoding to use for the output. For possible values, see NSStringEncoding.


If there is an error, upon return contains an NSError object that describes the problem. If you are not interested in details of errors, you may pass in NULL.

Return Value

true if the file is written successfully, otherwise false (if there was a problem writing to the file or with the encoding).


This method overwrites any existing file at path.

This method stores the specified encoding with the file in an extended attribute under the name The value contains the IANA name for the encoding and the CFStringEncoding value for the encoding, separated by a semicolon. The CFStringEncoding value is written as an ASCII string containing an unsigned 32-bit decimal integer and is not terminated by a null character. One or both of these values may be missing. Examples of the value written include the following:


  • UTF-8;134217984

  • UTF-8;

  • ;3071

The methods init(contentsOfFile:usedEncoding:), init(contentsOf:usedEncoding:), stringWithContentsOfFile:usedEncoding:error:, and stringWithContentsOfURL:usedEncoding:error: use this information to open the file using the right encoding.

See Also

Writing to a File or URL

func write(to: URL, atomically: Bool, encoding: UInt)

Writes the contents of the receiver to the URL specified by url using the specified encoding.

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