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Yale Astronomy

Interactive Data Language (IDL)

IDL Resources >> Helpful Tips

IDL Background Jobs

Hi team,

I've finally found a reliable way to run idl jobs in the background so that you can log out and not hog up a computer screen. (If you're not interested in running idl in the background then you can ignore this message.)

Here are the four easy steps:

  1. Add this alias to your .cshrc
    alias idlback '(/usr/bin/nohup /usr/bin/nice -15 $IDL_DIR/bin/idl < \!*.batch) >& \!*.log'
    (note: don't forget to source your .cshrc before trying to use it.)
  2. Create a text file with only the commands you wish to pass to idl. This file must end in ".batch".
  3. Log into a mac using
    ssh estrella -X
    (note: estrella can be replaced by 47uma and gandalf.)
  4. Change to the directory where your ".batch" file is located and type
    idlback filename &
    where "filename" ends in ".batch" but is omitted in this command.

Done! Now check to see that it is running with "top" and "more filename.log", which should contain all printed output from idl. You should be able to log out of the mac without disrupting the idl job. I recommend logging out and then back into the mac to double check that it is still running.

I still have had no luck running background jobs on the sun's. This isn't a major issue unless we have lots of cpu demand because the mac's should be able to handle at least 3x's as much as one sun-blade.

Happy computing,


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