EXTPROC Support

For compatiblility with CMD.EXE, CMD.EXE offers an external processor 
(EXTPROC) option for batch files that lets you define an external program 
to process a particular .CMD file.  To identify a .CMD file to be used 
with an external processor, place the string "EXTPROC" as the first word 
on the first line of the file, followed by the name of the external 
program that should be called.  CMD.EXE will start the program and pass it 
the name of the .CMD file and any command-line arguments that were 
entered. 

For example, suppose GETDATA.CMD contains the following lines: 

        EXTPROC D:\DATAACQ\DATALOAD.EXE
        OPEN PORT1
        READ 4000
        DISKWRITE D:\DATAACQ\PORT1\RAW

Then if you entered the command: 

        [d:\dataacq] getdata /p17

CMD.EXE would read the GETDATA.CMD file, determine that it began with an 
EXTPROC command, read the name of the processor program, and then execute 
the command: 

        D:\DATAACQ\DATALOAD.EXE D:\DATAACQ\GETDATA.CMD /p17

The hypothetical DATALOAD.EXE program would then be responsible for 
reopening the GETDATA.CMD file, ignoring the EXTPROC line at the start, 
and interpreting the other instructions in the file. It would also have to 
respond appropriately to the command-line parameter entered (/p17). 

Do not try to use CMD.EXE or Take Command as the external processor named 
on the EXTPROC line in the .CMD file.  It will interpret the EXTPROC line 
as a command to re-open themselves.  The result will be an infinite loop 
that will continue until the computer runs out of resources and locks up.