Using or in grep command

Question

I tried the following commands

cat filename.txt | grep "<Line: (429|6854)>"
cat filename.txt | grep "<Line: \(429\|6854\)>"

to show the lines containing <Line: 429> or <Line: 6854> but I'm not getting any output.

Answer 1

You have to use grep -E or egrep:

grep -E '<Line: (429|6854)>' filename.text