SFX commands: Update
<c> parameter can be either U or F character.
If <c> is U, SFX module will extract files, which copies are not already present on the disk, and files newer than their copies on the disk.
If <c> is F, SFX module will extract only those files, which are newer than their copies on the disk. If copy of extracted file is not present in destination folder, file will not be extracted in F mode.