Date: Sun, 08 Sep 2013 12:26:22 -0400 > From: Richard Stallman <[email protected]> > To: [email protected] (Karl Berry) > Subject: Re: --rundir for coding standards > > + The directory for installing data files which the programs modify > + while they run, that pertain to one specific machine, and which need > + not persist longer than the execution of the program. > > Those words are not clear to me. Are these temp files? > If not, how do they differ from temp files? >
Temporary files are stored until their content is consumed, so they are usually tied to a short-running process. /run is also tied to the lifetime of a process, but usually it is long-running. For example, it could hold: * "state" files, like pid files for daemons * FIFOs and AF_UNIX sockets Another use for /run is to place mountpoints that are not persistent across reboot, for example removable devices or Hurd-style virtual filesystems (Linux implements them in FUSE, the "filesystem in userspace" module). Putting them into /run ensures that /mnt (or an equivalent directory under the user's home directory) does not get crowded. Paolo
