Hi everyone, Guoqiang Pan has reported problems getting perl/Tk compiled and installed on his Red Hat system. Matt and Shelly both suggested that the problem was an unset environment variable and they suggested a solution. Guoqiang has told me privately that the suggestion helped and that he was then able to compile perl/Tk. Yay! He followed Matt's suggestion of using perl's CPAN interface for installing perl Tk (i.e. do "perl -MPCAN -e shell" at the command line, then "install Tk" at the cpan> prompt). This is a fine way of installing things, but Tk is a little bit different from most perl modules in that it's purpose is to draw things on the screen using X windows. X windows has some quirks and Guoqiang ran into a common stumbling block. The installation using the CPAN interface was proceeding properly until it got to the "make test" stage of the installation, which is when a bunch of tests are run to verify that the modules were built correctly. Most of the tests involve drawing things on the screen -- unsurprising since Tk is a GUI widget set. If you are logged in as a normal user, then you, the normal user, own the X windows process and only you or those to whom you have specifically granted permission can draw on the screen. Even root cannot do so unless you allow it. So, if you became root to run the CPAN interface by typing the "su" comand or the "sudo" command, you may not be able to successfully run the "make test" stage. To allow the "make test" thing to work, you need to execute the following command BEFORE becoming root and running CPAN: xhost + localhost This allows any user logged into your computer to write to the screen under X windows when you own the X windows process. Thus, it should also allow the "make test" stage to work. Alternately, you can log out as a normal user and log back in as root. Then root will own the X windows process and the "make test" stage of the CPAN installation or Tk should proceed without a problem. The good news is that once you get Tk installed, you almost certainly will not need to update it the next time that you update Athena and Artemis. The other good news (but not for Red Hat users apparently) is that installing from an RPM sidesteps this whole issue. I use SuSE (which I have long prefered to Red Hat -- two thumbs up for German engineering!) and its perl/Tk rpm works just fine. Hope that helps, B -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 222 Naval Research Laboratory phone: (1) 202 767 5947 Washington DC 20375, USA fax: (1) 202 767 1697 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b National Synchrotron Light Source Brookhaven National Laboratory, Upton, NY 11973 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/