How to recognize string in txt file and set it as variable

Question

Hi, 
I have txt file and somwhere in it string starting with:
data directory....:
How (using batch file) find it in the text, read and set the value as a variable? I mean the string is:
data directory....: c:\datadir
where what I mean value is  in this case "c:\datadir". So I want batch file to read the txt file, find string starting with "data directory....:" and then set "c:\datadir" as a variable. 
Best, mac

Answer 1

It's not very intuitive to do this sort of thing in a batch file. If you have the option to use PowerShell instead, I'd highly recommend it. It's the new way for performing command-line tasks in Windows, and there's no need to struggle with the old command
prompt anymore.
Here are PowerShell and batch examples of doing this type of string parsing:
# PowerShell:
$dataDirectory = Get-Content .\test.txt |
ForEach-Object {
if ($_ -match '^\s*data directory\.*:\s*(.+?)\s*$')
$matches[1]
break
$dataDirectory
# Batch file:
@echo off
setlocal EnableDelayedExpansion
set DATA_DIRECTORY=
for /F "tokens=1,* delims=:" %%a in (test.txt) do (
set PROPERTY=%%a
set PROPERTY=!PROPERTY:~0,14!
if /I "!PROPERTY!" equ "data directory" (
set DATA_DIRECTORY=%%b
:RemovingSpaces
if "%DATA_DIRECTORY:~0,1%" neq " " goto :SpacesRemoved
set DATA_DIRECTORY=%DATA_DIRECTORY:~1%
goto :RemovingSpaces
:SpacesRemoved
echo %DATA_DIRECTORY%
endlocal