       execl ?-argv0 argv0? prog ?arglist?
              Do  an execl, replacing the current program (either Extended Tcl
              or an application with Extended Tcl embedded into it) with  prog
              and passing the arguments in the list arglist.

              The  -argv0  options specifies that argv0 is to be passed to the
              program as argv [0] rather than prog.

              Note: If you are using execl in a Tk application and  it  fails,
              you  may  not do anything that accesses the X server or you will
              receive a BadWindow error from the X server.  This includes exe-
              cuting the Tk version of the exit command.  We suggest using the
              following command to abort Tk applications after an execl  fail-
              ure:

                  kill [id process]

              On Windows 95/NT, where the fork command is not available, execl
              starts a new process and returns the process id.
