exsex: A tool for extracting columns from SExtractor catalogs

I have written a quick perl script for extracting columns from SExtractor catalogs. Instead of scrolling throught the header, noting the columns numbers and typing an awkward script like

> awk 'NR>33 {print $2,$3,$31}' fred.cat > fredxymag

one types 

> exsex fred.cat X_IMAGE Y_IMAGE MAG_AUTO >fredxy mag
Which saves the step of having to look at the header. If the parameter doesn't exist, exsex will tell you so. It is easy to remember: exsex = extract from SExtractor. It is also robust if the columns get moved around.

It is available here.   (Do a <shift> click to save)

To use it on a SExtractor genterated with the CATALOG_TYPE parameter set to ASCII_HEAD

exsex <CATALOG NAME> <PAR1>  <PAR2>  <PAR3> ...

To use it on a SExtractor genterated with the CATALOG_TYPE parameter set to ASCII

exsex <CATALOG NAME> <PARAM FILE> <PAR1>  <PAR2>  <PAR3> ...

Where <CATALOG NAME> is the catalog name (with any extensions),  <PARAM FILE> is the parameter file used to generate the catalog (being sure to include the .param filename extension) and <PAR1> and so on are the desired SExtractor parameters. Any number of parameters may be listed. It is not necessary to captilize the parameters (x_image = X_iMaGe = X_IMAGE)

It is written in plain vanilla perl. It needs no compiling. Just type:
chmod u+x exsex
to make it executable. It has been slightly tested. The code is currently largely undocumented, in keeping with the SExtractor tradition.