Question

I need to create a directory full of data files. These files are are temporary, user-private files.

While the files are temporary, and it’s ok if they are deleted by the system, there’s a lot of them and I’d like to
reuse them if I can. Furthermore, I expect other applications (running as the same user) to access/create these files too. This means I need a standard protocol that will work across different programming languages.

Since I know someone will suggest it, I do not want to use ‘/tmp’ or ‘%TEMP% or the java system property java.io.tmpdir.
These directories are system-scoped. I’m also very interested in finding platform-standard or platform-approved methods over just finding a solution that works.

I’m trying to collect a list of where to locate these files for various platforms. Below is what I have so far, but I would really appreciate additional platforms and/or validation of what I’ve already found.

Answer 1

This is the best list I’ve found. If you have any corrections/suggestions, please let me know.

On Windows:

1. Create a directory “CompanyName” in the “local app data” directory. Find this via:

   1. The system environment variable LOCALAPPDATA, or

   2. Query the registry by executing the following command line:

      reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v Local AppData
      

On MacOSX:

1. $TMPDIR or Cocoa function NSTemporaryDirectory()
   • Cleared automatically every three days
2. mkdir -m 700 ~/Library/Caches/CompanyOrProductName
   • Not removed by system automatically (fine for my use case)
   • Not backed up by TimeMachine
3. mkdir -m 700 ~/Library/Application Support/CompanyOrProductName
   • Not removed by system automatically (fine for my use case)
   • Backed up by TimeMachine

On Linux:

1. mkdir -m 700 ~/.company-name

On Solaris / OpenSolaris:

1. ?

References:

• Cocoa with Love explains the three MacOSX options above and also discusses several security issues.