How to find if a file contains a given string using Windows command line

Question

I am trying to create a batch (.bat) file for windows XP to do the following:

If (file.txt contains the string 'searchString') then (ECHO found it!) 
ELSE(ECHO not found)

So far, I have found a way to search for strings inside a file using the FIND command which returns the line in the file where it finds the string, but am unable to do a conditional check on it.

For example, this doesn't work.

IF FIND "searchString" file.txt ECHO found it!

Nor does this:

IF FIND "searchString" file.txt=='' ECHO not found

Any Ideas on how this can be done?

Answer 1

From other post:

    find /c "string" file >NUL
    if %errorlevel% equ 1 goto notfound
        echo found
    goto done
    :notfound
        echo notfound
    goto done
    :done

Use the /i switch when you want case insensitive checking:

    find /i /c "string" file >NUL

Or something like: if not found write to file.

    find /c "%%P" file.txt  || ( echo %%P >> newfile.txt )

Or something like: if found write to file.

    find /c "%%P" file.txt  && ( echo %%P >> newfile.txt )

Or something like:

    find /c "%%P" file.txt  && ( echo found ) || ( echo not found )