You can verify the file system of the volume which is currently defined as startup disk and have it repaired. This is equivalent to using the feature Repair Disk of the Disk Utility of Mac OS X, with the difference that it will still be available even if the graphical user interface of Mac OS X is no longer operational.
If errors have been detected during the verification step, the standalone application might repeat the check automatically, depending on the type of problems found. This will ensure that you have a properly working file system at the end.
This feature corresponds with a certain verification procedure in the graphical main application of TinkerTool System. You should activate this function in case the main program is showing the following error message:
Mac OS X is currently unable to run any applications performing security-related features. The operating system is seriously damaged. The system folder for the storage of temporary objects (“/tmp”) is either missing or has invalid permission settings. TinkerTool System Release 2 must quit now.
It is harmless to use this function at any other time, however. The program is checking automatically whether repair is necessary or not.
You can have the system verify whether the currently set permissions for system folders and system files are still matching the settings Apple had defined at installation time. If differences have been detected, the permission settings will be reset to their recommended values. User folders and files will not be touched. This feature is equivalent to the function Repair Disk Permissions of Disk Utility, or Maintenance > Permissions in TinkerTool System. Here, it will still be available in case the graphical user interface of Mac OS X is no longer working.
OS X Mavericks is not capable of running this procedure in single-user mode at this time. You must use Repair Disk Permissions of Disk Utility as an alternative, after starting your computer in Recovery Mode.
You can let all of the four repair features run automatically after each other without any user intervention being necessary. This is helpful to “blindly” bring the system into a sufficiently good state —without any special strategy or testing—, solving many typical startup problems of Mac OS X automatically.