The XDG Base Directory Specification is a very interesting spec for user directories. It also provides good default values, except for XDG_RUNTIME_DIR.

Now I am writing a software that needs to create named pipes. It is a per-user client-server framework (there is a FIFO for the server and a FIFO per client).

If XDG_RUNTIME_DIR is not defined, I am currently using a per-user subdirectory in /tmp — but it does not ensure all the specified conditions (viz. the paragraph starting with "The lifetime of the directory MUST be bound to the user being logged in…")

Is /tmp/myserver-$USER good enough?

Edit

I saw elsewhere a few suggestions:

• . is quite unsatisfactory (at least because it is not an absolute path).
• I also saw /var/run/user/$USER — not bad, but that directory does not exist (at least on my box running a Debian testing)