Check a string for a substring in a batch file (Windows)?

Question

Let's say I have some text in a variable called $1. Now I want to check if that $1 contains a certain string. If it contains a certain string I want to print a message. The printing is not the problem, the problem is the check. Any ideas how to do that?

Answer 1

The easiest way in my opinion is this :

set YourString=This is a test

If NOT "%YourString%"=="%YourString:test=%" (
    echo Yes
) else (
    echo No
)

Basiclly the string after ':' is the string you are looking for and you are using not infront of the if because %string: * % will remove the * from the string making them not equal.

Answer 2

The SET search and replace trick works in many cases, but it does not support case sensitive or regular expression searches.

If you need a case sensitive search or limited regular expression support, you can use FINDSTR.

To avoid complications of escaping special characters, it is best if the search string is in a variable and both search and target are accessed via delayed expansion.

You can pipe $1 into the FINDSTR command with the ECHO command. Use ECHO( in case $1 is undefined, and be careful not to add extra spaces. ECHO !$1! will echo ECHO is off. (or on) if $1 is undefined, whereas ECHO(!$1! will echo a blank line if undefined.

FINDSTR will echo $1 if it finds the search string - you don't want that so you redirect output to nul. FINDSTR sets ERRORLEVEL to 0 if the search string is found, and 1 if it is not found. That is what is used to check if the string was found. The && and || is a convenient syntax to use to test for match (ERRORLEVEL 0) or no match (ERRORLEVEL not 0)

The regular expression support is rudimentary, but still useful.

See FINDSTR /? for more info.

This regular expression example will search $1 for "BEGIN" at start of string, "MID" anywhere in middle, and "END" at end. The search is case sensitive by default.

set "search=^BEGIN.*MID.*END$"
setlocal enableDelayedExpansion
echo(!$1!|findstr /r /c:"!search!" >nul && (
  echo FOUND
  rem any commands can go here
) || (
  echo NOT FOUND
  rem any commands can go here
)

Answer 3

As far as I know cmd.exe has no built-in function which answers your question directly. But it does support replace operation. So the trick is: in your $1 replace the substring you need to test the presence of with an empty string, then check if $1 has changed. If it has then it did contain the substring (otherwise the replace operation would have had nothing to replace in the first place!). See the code below:

set longString=the variable contating (or not containing) some text

@rem replace xxxxxx with the string you are looking for
set tempStr=%longString:xxxxxx=%

if "%longString%"=="%tempStr%" goto notFound
echo Substring found!
goto end

:notFound
echo Substring not found

:end