Gets the length of a file.
long _filelength( int fd ); __int64 _filelengthi64( int fd );
Target the file descriptor.
_filelengthi64 return the file length, in bytes, of the target file associated with
fd is an invalid file descriptor, this function invokes the invalid parameter handler, as described in Parameter Validation. If execution is allowed to continue, both functions return –1L to indicate an error and set
For more compatibility information, see Compatibility in the Introduction.
See the example for _chsize.