Semaphore files

CrimeStar makes use of semaphore file to track certain events and activities. A semaphore file is simply a file that tells CrimeStar how to behave under certain conditions. The following is a list of the semaphore files used by CrimeStar with a brief description of how the file is used by CrimeStar. Typically semaphore files are empty, or their contents are insignificant to the process they trigger. The mere existence or non-existence of the file is what matters.

Start.zzz : This file is used by CrimeStar upon startup to determine if CrimeStar should compare the current database files with the data dictionary definition tables. This file is distributed with CrimeStar and causes CrimeStar to build or check the database structure. Once the database build or structure check is complete CrimeStar deletes this file.

Repair.zzz : This file is an Automatic Safeguard. A common problem that can lead to troubles is the computer being turned off without CrimeStar and other applications being properly shut-down. To alert you of this circumstance CrimeStar uses the Repair.zzz semaphore file to flag when the potential for a problem may have occurred. When you start CrimeStar it looks for and then creates a file named ‘repair.zzz’ in the default CrimeStar directory. When CrimeStar is properly shut-down this file is deleted by CrimeStar. If this file is found by CrimeStar when the program starts then CrimeStar knows that the program was not properly shut-down the last time it was run. It then provides the user with a message indicating the possibility of file damage, and it offers to let the user run the repair utility.