In Fedora, the files that stored in /tmp directory seems would be removed after a certain period of time without operation on it. Which kind of time (last modification time, create time or read time) can be set using different parameters when invoke a program named tmpwatch. Beware in mind, this works only in Fedora series. I am not sure for other Linux distributions.
The tmpwatch is a watching program that is invoked daily-based by cron. A script is also called tmpwatch is in /etc/cron.daily/ directory to invoke the program in /sbin directory.
In my case, I want to keep my file in /tmp directory without bothering with the tmpwatch's auto-removing. So I am able to set myself to be a exclude user by -U parameter for tmpwatch in shell scripts in cron directory.
And it should be work.
