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Hi,I am really stuck here and could use some advice. I am a beginner with IRAF, I have been running through the IRAF tutorials provided on the IRAF Project homepage. When using certain tasks, I have encountered:

'ERROR: bus error'. As in the example below, I was following through exercise 2, using the 'colbias,' task with a list of files, but the task stopped after making only one output file and then gave me the 'bus error'. Then I tried to plot the file with implot, and the result was a blank screen and: 'ERROR: segmentation violation'. I haven't been able to find anything regarding the 'bus error' on the forum. If any one can explain it I would greatly appreciate it. Thanks,
Scott

bias> colbia m92*.fits
colbias m92001.fits (yes): yes
ERROR: bus error
bias> implot tr92001.fits
ERROR: segmentation violation

If this is a linux system it sounds like the 'stacksize' problem. This was fixed in recent versions of IRAF but basically what it means is that on some systems you need to issue the command:[code:1:8753670e81]
limit stacksize unlimited # for C-shell
ulimit -s unlimited # for Bourne shell
[/code:1:8753670e81]Do this before logging into the CL, on a recent system this should be done automatically in the 'cl' command itself, if you try the above commands and it seems to fix the problem we can figure out why this may not be working. It would help to know which OS and IRAF version you are using.Cheers,
-Mike

Hi,
Thanks for the response. I am working on a Mac OS X 10.5 with IRAF version 2.14. Based on what you said, it seems like the 'stacksize' problem should be fized in these versions. I still tried issuing the command you suggested (Bourne shell), but I apparently do not have permission:bash-3.2$ ulimit -s unlimited
bash: ulimit: stack size: cannot modify limit: Operation not permittedI even logged on as the root user and tried it:scott-barrowss-imac:~ root# ulimit -s unlimited
-sh: ulimit: stack size: cannot modify limit: Invalid argumentMaybe there's a problem with the output file, though I'm not really sure why there would be. Maybe we can try something else? Thanks.
- Scott

Hi,
I think I figured out the problem. I had previously been running 'colbias' on 'fits' files. So, before unpacking the 'fm' files in exercise 2, I set the image type to 'imh' then used rfits to unpack the files into .imh and .pix files, respectively. Then I ran the 'colbias' task on the 'imh' files and it worked beautifully. I learned this by reading your response to the 'rfits' topic posted earlier. Again, thanks for the help.
- Scott