Batch file include external file for variables

Question

I have a batch file and I want to include an external file containing some variables (say configuration variables). Is it possible?

Answer 1

Batch uses the less than and greater than brackets as input and output pipes.

>file.ext

Using only one output bracket like above will overwrite all the information in that file.

>>file.ext

Using the double right bracket will add the next line to the file.

(
echo
echo
)

This will execute the parameters based on the lines of the file. In this case, we are using two lines that will be typed using "echo". The left bracket touching the right parenthesis bracket means that the information from that file will be piped into those lines.

I have compiled an example-only read/write file. Below is the file broken down into sections to explain what each part does.

@echo off
echo TEST R/W
set SRU=0

SRU can be anything in this example. We're actually setting it to prevent a crash if you press Enter too fast.

set /p SRU=Skip Save? (y): 
if %SRU%==y goto read
set input=1
set input2=2
set /p input=INPUT: 
set /p input2=INPUT2: 

Now, we need to write the variables to a file.

(echo %input%)> settings.cdb
(echo %input2%)>> settings.cdb
pause

I use .cdb as a short form for "Command Database". You can use any extension. The next section is to test the code from scratch. We don't want to use the set variables that were run at the beginning of the file, we actually want them to load FROM the settings.cdb we just wrote.

:read
(
set /p input=
set /p input2=
)

So, we just piped the first two lines of information that you wrote at the beginning of the file (which you have the option to skip setting the lines to check to make sure it's working) to set the variables of input and input2.

echo %input%
echo %input2%
pause
if %input%==1 goto newecho
pause
exit

:newecho
echo If you can see this, good job!
pause
exit

This displays the information that was set while settings.cdb was piped into the parenthesis. As an extra good-job motivator, pressing enter and setting the default values which we set earlier as "1" will return a good job message. Using the bracket pipes goes both ways, and is much easier than setting the "FOR" stuff. :)