IRAF is now a freestanding shell script, which does everything internally without monkeying with your current shell's environment variables. Options include launching SAOImage DS9 in the same working directory, and performing the initial setup stage in which the traditionalist would execute mkiraf by hand.


  • If you have not got the freestanding 64-bit IRAF installed, the wrapper script falls back to the old 32-bit copy in SciSoft, which is known to have several errors in. Scisoft as an entirety is slowly being replaced.

    • The freestanding 64-bit IRAF can be installed from Self-Service if necessary.

  • The wrapper script always activates SciSoft in order to obtain its PyRAF; and SciSoft layers its own rather out-of-date set of packages on top of the system Python (and its out-of-date package set). This will break the library-search mechanisms for other Pythons, eg in MacPorts or your virtual Python environment.

    • Please see instead the separate instructions for using PyRAF from within one's virtual Python setup.

    • If you are going to use a virtual Python setup, any direct or indirect Activation of SciSoft in the same shell session, still worse in your shell startup files, is hereby officially Considered Harmful.

For completeness, for the aforesaid traditionalists, and for those who want to know what's going on under the covers, a record of how to use IRAF the Hard Way can be made available (some of this information is in the old PyRAF page). We advise using the Easy Way instead for most users .... once it's all there, and all documented. Please stand by.

Please see also:


  • iraf

    Run an instance of ecl within an invocation of xgterm, with ${HOME}/iraf as its initial working directory.

  • iraf-new

    Use this instead (here and below) to ensure you're using the freestanding 64-bit version. If it needs to be installed, you'll be told so.

  • iraf +here

    Ditto, but use your shell's current directory.

  • iraf +ds9
  • iraf +ds9 +here

    Additionally launch DS9 (in the default or current directory respectively).

  • iraf --help

    Yield further information, and exit without launching anything.

  • iraf --setup

    Additionally be reminded how to set up IRAF by hand for use under your login, and exit.

  • iraf --init
  • iraf --init +here

    Do said setup automatically (in the default or current directory respectively), and exit.

Please note that you will see "Package Scisoft (inc IRAF) available" (plus some Scisoft version information) when you run the script, but this only refers to what's going on inside the script itself, and doesn't affect your current shell. If you wish to run other IRAF (or Scisoft) programs, you will still need to say "Activate scisoft" at the command line for yourself first in the usual manner.

Bonus software:

  • If you have installed SAOImage DS9 7.1 from the Astrophysics section of Self-Service, iraf +ds9 will use this version of DS9 in preference. Please see ds9 in wrapper scripts for more information.

  • If you have installed the freestanding 64-bit IRAF from Self-Service, this will be used in preference to SciSoft's instance. This lifts certain size-related limits which some users of SciSoft's IRAF (and PyRAF) have been experiencing.


The IRAF script is inspired by a script by Alison Crocker, which has been preserved for the record (and for educational purposes) in the Footnotes section of Applications Setup.

Categories: Apple | Astro software | Astrophysics | IRAF | Mac | OS X | PyRAF