write(to:atomically:encoding:)

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

Declaration

func write(to url: URL, atomically useAuxiliaryFile: Bool, encoding enc: UInt) throws

Parameters

url:
The URL to which to write the receiver. Only file URLs are supported.
useAuxiliaryFile:
If True, the receiver is written to an auxiliary file, and then the auxiliary file is renamed to url. If False, the receiver is written directly to url. The True option guarantees that url, if it exists at all, won’t be corrupted even if the system should crash during writing.
The useAuxiliaryFile parameter is ignored if url is not of a type that can be accessed atomically.
enc:
The encoding to use for the output.

Discussion

This method stores the specified encoding with the file in an extended attribute under the name com.apple.TextEncoding. 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:

MACINTOSH;0
UTF-8;134217984
UTF-8;
;3071

The methods init(contentsOfFile:usedEncoding:), NSString/init(contentsOfURL:usedEncoding:)-2c72d, stringWithContentsOfFile:usedEncoding:error:, and NSString/init(contentsOfURL:usedEncoding:)-9jrum use this information to open the file using the right encoding.