The following are demonstrations of the whatexec.d script.


Here we run it while a few commands are also executed,

   # ./whatexec.d
   PEXEC            EXEC                                   OK TYPE
   bash             /usr/bin/clear                          Y #!/u\0
   bash             /sbin/sh                                Y \177ELF\0
   clear            /usr/bin/tput                           Y \177ELF\0
   bash             /export/home/brendan/DOOM.EXE           N MZ\644\0
   ^C

whatexec.d has first found that "clear" was run, which has a type that
begins with "#!" - a script. clear runs "sh" and "tput", both ELF files.

We finish by attempting to run a MZ file, "DOOM.EXE", which is rejected
(OK is "N").