How to get lines that contain string in a file?

Question

In Linux, How do I display lines that contain a string in a text file, such as:

search "my string"  file_name

How do I make the search case sensitive/insensitive? And how do I also display the line numbers?

Regards

Answer 1

well

grep -n "my string" file_name 

will do for your particular query. GREP is by default case sensitive in nature and to make it case insensitive you can add -i option to it. The -n option displays the line numbers. For other myriad options, I recommend

man grep

for more interesting pattern matching capability of GREP.

Answer 2

#!/bin/bash
cd $HOME/Desktop
s=xda
m=$(grep -n "$s" $HOME/Desktop/tt.txt )
if [ "$m" = "$s" ] ;then
    echo "success"
else
  echo "fail"
fi