If your batch script needs to determine if a string is a sub-set of a larger string,
the easiest method is to use environment variable string substitiution:
set work=%string:substring=%
if not "%work%" EQU "%string%" @echo %string% contains substring.
If the substring is an environment variable,
set work=%string:%substring%=%
or set work=%%string:%substring%=%% does NOT work.
You can use the FOR command to parse this expression,
but using the CALL command is much easier:
call set work=%%string:%substring%=%%
if not "%work%" EQU "%string%" @echo %string% contains %substring%.
Example
If you need a quick way to determine if a folder is included in your very long SYSTEM PATH,run CheckPath Folder, i.e; checkpath "c:\program files\support tools".
CheckPath.bat uses Reg.exe from the
Windows 2000 Support Tools,
or from %WinDir%\System32 of a Windows XP Professional installation,
or from Supplement 4 of the Windows NT 4.0 Resource Kit,
to retireve the SYSTEM PATH.
CheckPath.bat contains:
@echo off
setlocal
if \{%1\}==\{\} goto syntax
set fold=%1
:: Strip quotes and various combinations of trailing \ and double ;
set folder=%fold:"=%\##
set folder=%folder:\\##=%
set folder=%folder:\##=%
set folder=%folder%;##
set folder=%folder:;;##=%
set folder=%folder:##=%\##
set folder=%folder:\\##=%
set folder=%folder:\##=%
set folder=%folder%;##
set folder=%folder:;;##=%
set folder=%folder:##=%
:: Retrieve System Path.
for /f "Skip=2 Tokens=1,2*" %%i in ('REG QUERY "HKLM\System\CurrentControlSet\Control\Session Manager\Environment" /v PATH') do set syspath=%%k
:: Force trailing ;
set workpath=%syspath%\##
set workpath=%workpath:\\##=%
set workpath=%workpath:\##=%;
call set work=%%workpath:%folder%=%%
if "%work%" EQU "%workpath%" goto :end
@echo Found %fold% in path=%syspath%
goto :end
:syntax
@echo Syntax: CheckPath Folder
:end
endlocal
