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It didn’t matter because the disk permissions being inspected were always compared to the defaults stored in the local /Library/Receipts/ directory. Prior to 10.6 you could use any version of Disk Utility on any version of Mac OS X to Repair Disk Permissions. If the permissions differ, Disk Utility reports the difference and corrects them.
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bom files in /Library/Receipts/ and compares its list to the actual permissions on each file listed. In Mac OS X v10.5 or earlier, when you repair disk permissions Disk Utility reviews each of the. Each of those “.bom” files contains a list of the files installed by that package, and the proper permissions for each file. These files don’t take up much disk space and you shouldn’t put them in the Trash.
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Each time something is installed from a package file, a “Bill of Materials” file (whose filename extension is “.bom”) is stored in the package’s receipt file, which is kept in /Library/Receipts/ in Mac OS X v10.5 and earlier. Many things you install in Mac OS X are installed from package files (whose filename extension is “.pkg”). My answer, “when is the last time you booted into Mac OS 9?” Readers ask me when is a good time to Repair Disk Permissions? By Thomas Brand Tue 8/20 Repair Disk Permissions
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