/var/tmp vs. /tmp

[Louis Granboulan <Louis.Granboulan@ens.fr>]

Gerhard Niklasch answered on pari-users mailing list :
> > When UNIX PARI does MPQS, it uses several temporary files in /var/tmp.
> 
> Or wherever you point GPTMPDIR in the environment.

I am wondering why /var/tmp is preferred to /tmp
Usually, /tmp is better for such temporary files.
/var/tmp is needed for files to be preserved after
reboots, and that constraint is useless for MPQS.

On some OS (Solaris) /tmp is much faster than /var/tmp,
even when written to disk.

Louis