Without login.cl iraf/pyraf does not work properly. Some commands may execute (like zerocombine, ie the binaries) but when the command will need to retrieve some information (like wavelength calibration/plotting, even shell commands like ls ) it will not respond (see error examples below).
IRAF: Select a directory (like user’s home) and “mkiraf” (type it in a terminal) in this. This creates the login.cl and uparm directory. Then you should always start iraf from that directory (one of the main drawbacks).
PyRAF: Make an iraf directory (at user’s home) and inside this “mkiraf”. Then you can start pyraf from any directory (as it will always find the iraf directory previously created to search for parameters and settings). When you first run pyraf it will also create a pyraf directory (including a cache directory)
PyRAF errors (showing that a login.cl file is missing):
--> epar ccdred
...
File "/scisoft/lib/python2.5/site-packages/pyraf/iraffunctions.py", line 3051, in _expand1
(varname, instring))
IrafError: Undefined variable `uparm' in string `uparm$imdccdred.par'
--> ls
Traceback (innermost last):
File "", line 1, in
NameError: name 'ls' is not defined
