SET environment variable in batch file from the contents of a text file

Posted on 2008-06-23
Last Modified: 2012-06-27
x.txt contains the name of a computer

I need

to get the contents of x.txt and use that as the computername
I wanted to do so via the SET command and environment variables.

SET F=TYPE x.txt
did't give me what I'd like.... is there a way to do it with SET?
Is there a better way to accomplish this from a batch file?

Question by:SStory
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LVL 85

Accepted Solution

oBdA earned 250 total points
ID: 21850576
Enter "help for" in a command window.
To process output of another command, you'll need the "for /f" function:

for /f %%a in ('type x.txt') do @echo %%%%a now contains: %%a

You can enclose several commands in round brackets:

for /f %%a in ('type x.txt') do (
  echo Processing %%a ...
  ping %%a

And even subroutiones are possible:

for /f %%a in ('type x.txt') do (
  set Machine=%%a
  call :process
:: *** Leave the script
goto :eof
:: *** Subroutine process starts here:
echo Processing %Machine%
ping %Machine%
goto :eof

You might want to chekc out, lots of nice scripts there.
LVL 13

Expert Comment

ID: 21853746
Elaborating on the above:

for /f %%a in (x.txt) do set target=%%a & call :routine
goto end

for /f %%b in (b c d) do call %%b.bat %target%


Then within each of your sub-scripts you will need to set an environment variable to %1 which will be the computername that is being passed to it by :routine.


set computer=%1
ping %computer%


LVL 25

Author Comment

ID: 21855070
Thanks for your reply, but this isn't really what I had in mind.
I don't have one batch calling a bunch of batches. I have a bunch of batches to do config stuff. I may only run one of them. The problem is I am about to move them from one machine to another and wanted a way to have all batches, when they first run, read a text file that only contains COMPUTERNAME
and use that to get to the correct location.  This is needed because many of the batches copy from a network location to a local machine.  So all I really need is a way to set an environment variable at the top of each batch file based upon the value in that one file and then use that throughout the batch file.

So, is there no way to do this? I know that Type Myfile.txt would output the results of myfile.txt, but how can I get that into the environment variable?

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LVL 25

Author Comment

ID: 21855088
I'm sorry, I didn't see the first reply... I will try it.
LVL 25

Author Closing Comment

ID: 31469943
Great!  This did exactly what I needed!
LVL 13

Expert Comment

ID: 21855134
The same code applies.

At the beginning of each batch file do this:

for /f %%a in (x.txt) do set computer=%%a & call :restofscript
goto end

blah blah

This will read the text file and set the computer environment variable for you to use throughout the rest of the script. Dead easy.



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