In the top part of the process popup window, process information is
shown by running a "ps"-like program. What command to invoke is
determined initially by the value associated with the C<-pscmdline>
option or the pscmdline X resource if it is not set as a command
option, or if neither of these are set then by a platform-specific
C<ps> command string set when this xps was configured and compiled.

Well, this is not the whole truth. Having written all of the above,
you can dynamically change this here as the program is running!
Should you want different information or in a different format, here
is where you can customize.

The "ps"-like command string should have C<%d> or C<%ld> as a
placeholder for the process id or "pid".  Chances are that the command
string will want to refer to the process id somewhere.  The process id
of the selected process will be substituted for the first occurrence of
C<%d> or C<%ld> (if any) found. After substitution, the command string
is executed and the output, which might be several lines, will be put
in the scrolled window.

Example (for Linux):

 /bin/ps w %d

If you have C<lsof> installed, another interesting possibility
is:

 lsof -p %d

