Batch file: Find if substring is in string (not in a file)

Question

In a batch file, I have a string abcdefg. I want to check if bcd is in the string.

Unfortunately it seems all of the solutions I'm finding search a file for a substring, not a string for a substring.

Is there an easy solution for this?

Answer 1

Yes, you can use substitutions and check against the original string:

if not x%str1:bcd=%==x%str1% echo It contains bcd

The %str1:bcd=% bit will replace a bcd in str1 with an empty string, making it different from the original.

If the original didn't contain a bcd string in it, the modified version will be identical.

Testing with the following script will show it in action:

@setlocal enableextensions enabledelayedexpansion
@echo off
set str1=%1
if not x%str1:bcd=%==x%str1% echo It contains bcd
endlocal

And the results of various runs:

c:\testarea> testprog hello

c:\testarea> testprog abcdef
It contains bcd

c:\testarea> testprog bcd
It contains bcd

A couple of notes:

• The if statement is the meat of this solution, everything else is support stuff.
• The x before the two sides of the equality is to ensure that the string bcd works okay. It also protects against certain "improper" starting characters.