Setting variable problem in .bat or .cmd script ?

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Setting variable problem in .bat or .cmd script ?

#1 Post by 03bluecoupe » 10 Sep 2020 15:39

Hi all, forum newbie here. I'm an old AIX/Linux guy but my wife has a side business that I need to support so I'm in the DOS world...
I thought I was trying to do something extremely simple. Either that's not the case or I'm just flat being dense....

In a .bat/.cmd file run from the command prompt, I just want to do:

If $Variable3 is NULL then set Variable3=0

Then printing out Variable_3 (just as a sanity check) I've tried every syntax I can find and think of, as well as a few others. ;)
I'm just at a loss. It seems like it should be a straight forward "if then else" statement but....

Anyone set me straight?


Posts: 4194
Joined: 23 Dec 2011 13:59

Re: Setting variable problem in .bat or .cmd script ?

#2 Post by Squashman » 10 Sep 2020 19:22

You can see the proper syntax for a command by typing the command name followed by a question mark from the cmd prompt.

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if /?
But it is usually a lot easier just to reference Microsoft's documentation but I usually use SS64.

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IF NOT DEFINED variable3 set "variable3=0"
echo %variable3%

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IF "%variable3%"=="" set "variable3=0"
echo %variable3%

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