Search files that has a substring and print the lines?

Question

I was trying to find files in sub-directory that that has a substring and print the files and the lines. But my command only catch files that contains the whole word. Could you please let me know why and correct me?

For example, some my files contain the "my_isr" word.

1. Working command (print files and lines): grep -rnw . -e "my_isr"

2. Non-working command (no matched files): grep -rnw . -e "isr"

Answer 1

The -w flag in your commands causes your version of grep to only match whole words; dropping that will match on arbitrary substrings:

grep -rn . -e isr