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

Let's not forget good old parameters. When starting your *.bat or *.cmd file you can add up to nine parameters after the command file name:

call myscript.bat \\path\to\my\file.ext type
call myscript.bat \\path\to\my\file.ext "Del /F"

Example script

The myscript.bat could be something like this:

@Echo Off
Echo The path of this scriptfile %~0
Echo The name of this scriptfile %~n0
Echo The extension of this scriptfile %~x0
Echo.
If "%~2"=="" (
   Echo Parameter missing, quitting.
   GoTo :EOF
)
If Not Exist "%~1" (
   Echo File does not exist, quitting.
   GoTo :EOF
)
Echo Going to %~2 this file: %~1
%~2 "%~1"
If %errorlevel%  NEQ 0 (
   Echo Failed to %~2 the %~1.
)
@Echo On

Example output

c:\>c:\bats\myscript.bat \\server\path\x.txt type
The path of this scriptfile c:\bats\myscript.bat
The name of this scriptfile myscript
The extension of this scriptfile .bat

Going to type this file: \\server\path\x.txt
This is the content of the file:
Some alphabets: ABCDEFG abcdefg
Some numbers: 1234567890

c:\>c:\bats\myscript.bat \\server\path\x.txt "del /f "
The path of this scriptfile c:\bats\myscript.bat
The name of this scriptfile myscript
The extension of this scriptfile .bat

Going to del /f  this file: \\server\path\x.txt

c:\>

Answer 2

The best option according to me is to have key/value pairs file as it could be read from other scripting languages.

Other thing is I would prefer to have an option for comments in the values file - which can be easy achieved with eol option in for /f command.

Here's the example

values file:

;;;;;; file with example values ;;;;;;;;

;; Will be processed by a .bat file
;; ';' can be used for commenting a line

First_Value=value001

;;Do not let spaces arround the equal sign
;; As this makes the processing much easier
;; and reliable

Second_Value=%First_Value%_test

;;as call set will be used in reading script
;; refering another variables will be possible.

Third_Value=Something

;;; end

Reading script:

@echo off

:::::::::::::::::::::::::::::
set "VALUES_FILE=E:\scripts\example.values"
:::::::::::::::::::::::::::::

FOR /F "usebackq eol=; tokens=* delims=" %%# in (
    "%VALUES_FILE%"
) do (
    call set "%%#"
)

echo %First_Value% -- %Second_Value% -- %Third_Value%

Answer 3

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
)<file.ext

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=
)<settings.cdb

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. :)