🚀 go-pugleaf

In a previous article, yogi@cs.ubc.ca (Yossi Gil) says:

>ts@uwasa.fi (Timo Salmi) writes:
>
>>As you might know I have a large collection of batch files and
>>tricks garbo.uwasa.fi:/pc/ts/tsbat36.zip. I am always looking for
>>useful new information for it.
>
>Well, I have this other discovery that I try to offer every year
>or so, but it still remains unnoticed. I hope that you will add
>this to your tips&tricks so that I will not have to pound on this
>again in a year from now. 
>
>How to prevent ctrl-breaks during execution of autoexec.bat? 
>------------------------------------------------------------
>The "ctty nul" command is a well known trick, but it doesn't hold
>if the user types in ^C quickly. One usually puts "@echo off" at the
>beginning of the batch file. These leavs even more time to the
>intruding user to break. 
>
>My trick is to create
>	shell=command.com /p nul line in my config.sys file. This will
>make command.com start with the nul device as its standard
>input/output. It is undocumented, but worked in all of the many dos
>versions I have tried it on.
>
>And yet another relatively unknwon features of COMMAND.COM. Did you
>know that the following would work? Can you figure out what it will
>do?
>
>	<NUL> con ver 

Same as ver <nul >con, or just ver since it takes no input.
>
>as well as
>
>	<CON> nul vol 

Does nothing:  Sends the volume label to nul.  Dos has never been too
picky about where <, > redirections go..
>
>not mentioning
>
>	if not if == not shift else ; endif 

Shifts (I think else ; endif is ignored as an arguement to shift)
because if is not the same as not.
>
>These may prove useful to encrypt your batch files. 

Confused me for a bit.

-- 
|Jeff Epler               Additions Welcome           c(-8 ;-) >{8-) |
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| >X^P                                              Lincoln, Nebraska|