how to get file name

One question pls advice,

I have 100 files in some file there is written character "password=abcd". so i will do this

# cat *.* |grep "password=abcd" i think it will show but i dont know which file have this thing written how do i know that where that thing is written in 100 files, can i get the name of file.

pls advice.

Thanks,
bash

cat is useless, use just grep , and you should read man grep

grep -l "password=abcd" *.*

Thanks,

its working.