Looking at the source code of mktemp suggests that it generally uses the TMPDIR environment variable to specify an alternative to /tmp when options such -p and -t are not given.
However, the documentation only mentions TMPDIR in the context of the -p and -t options. The info page has an example that seems to imply the general use of of TMPDIR but that is as far as it goes. I think there should be an "ENVIRONMENT VARIABLES" section that lists TMPDIR and explains how it is used. I would supply a patch but I don't understand enough texinfo to be able to figure out how to do this in doc/coreutils.texi. :-( peace & happiness, martin
