The /tmp and /var/tmp directories are both used to store temporary files, but their use is slightly different.
When a program writes temporary files in /tmp , don't expect to find it at the launch of another program..
, don't expect to find it at the launch of another program.. Indeed this directory can be cleaned out anytime. In the vast majority of distributions, this directory is cleaned at each reboot.
However, the files written to /var/tmp will be kept after restart.
Thanks to sebsauvage for this tip.