Question

I’m using the -l flag with grep to just print the matching file names.

I want to then list the results (files) in ascending order i.e. newest last.

Obviously

grep -l <pattern> *.txt | ls -rt

is not what I need, since the ls -lrt merely outputs all files.

Answer 1

Try:

ls -rt *.txt | xargs grep -l <pattern>

We first use ls to list *.txt files and sort them by modification time (newest last), then for each entry run them through grep so we only print out files that contain the pattern.