Trying to find files with FINDSTR using pattern1 and pattern2 in Windows Command prompt

Question

I am trying to files in a dir using the command prompt with the line.

findstr /m /i "Pattern1" *.txt | findstr /m /i "Pattern2" *.txt

The command does return results, but only for Pattern2

Answer 1

To AND the patterns parse the results of the first findstr with a for /f

@Echo off
for /f "delims=" %%A in (
  'findstr /m /i "Pattern1" *.txt 2^>Nul'
) do findstr /mi "Pattern2" %%A 1>Nul 2>&1 && Echo %%A matches both Patterns

If the two patterns appear in an order on the same line, you could have one regex like

findstr /m /i "Pattern1.*Pattern2" *.txt

Otherwise findstr regex capabilities are quite limited.