
This is the home web page for the file command:

  https://www.darwinsys.com/file/

Here is their github page.

  https://github.com/file/file/tree/master/magic/Magdir

I used this tool to download just the Magdir directory:

  https://download-directory.github.io/

For reasons unknown, several of the files in that directory raise errors when compiling
the magic file.  Running this command generates a list of errors:

  file -m Magdir -C

I remove the files listed in the error messages:

 mkdir -p trash
 rsync -auv Magdir/ myMagdir/
 foreach f ( `file -m myMagdir -C | & awk -F, '{print $1}' | sort | uniq | grep myMagdir` )
   mv $f trash/
 end

Then compile this new directory: 

  file -m myMagdir -C

We can use the new magic file:

  file -m myMagdir.mgc o60523g0045o.2132764.wrp.2688740.skycell.1566.004.pswarp.mdc

Fortuitously, the "DOS/MBR boot sector" magic numbers are among these files which
do not compile, specifically in Magdir/filesystems

The new magic file (myMagdir.mgc) is rather large: 5.3MB.  

Within the IPP, we use the command 'file' in order to distinguish compressed MDC files
from uncompressed files.  For this purpose, we only need a magic file built using the
file Magdir/compress:

  cp myMagdir/compress .
  file -m compress -C

This yields 'compress.mgc'

Unfortunately, the same magic file cannot be used by the binaries on both Ubuntu and Gentoo.

So, to address the specific IPP issue, we need to install a different version of the
file in some discoverable / defined location which depends on the build architecture.

