How to truncate x bytes from file

Question

Quite simply, how do I remove x amount of bytes, or a string from (the end of) a file..? I know how to append bytes — I need to do the opposite.

Unfortunately I haven't found any examples of how to do this :-/

NSFileHandle* fh = [NSFileHandle fileHandleForUpdatingAtPath: path];
    [fh seekToEndOfFile];

    ??

Answer 1

NSFileHandle has a truncateFileAtOffset method that does exactly what you want.

Answer 2

Given the NSString sFilePath variable is set, this is how you could truncate the file to 0 bytes:

NSFileHandle *hFile;
hFile = [NSFileHandle fileHandleForUpdatingAtPath:sFilePath];
[hFile truncateFileAtOffset: 0];
[hFile closeFile];