Linux/Unix: grep Command Show Line Numbers While Displaying Output

The grep command is used to search for a pattern in a file or files. To display the line numbers along with the matching lines, you can use the

-

option.

Here's an example:

grep -n 'pattern' file.txt

In this example,

patte

is the string you're searching for, and file.txt is the file you're searching in. The

-

option causes grep to display the line number of each matching line.

You can also use grep to search for a pattern in multiple files by specifying the file names separated by spaces:

grep -n 'pattern' file1.txt file2.txt file3.txt

If you want to search for a pattern recursively in a directory and its subdirectories, you can use the -r option:

grep -nr 'pattern' directory

In this example, directory is the top-level directory you want to search in. The -r option causes grep to search recursively in all subdirectories of directory. The

-

option causes grep to display the line number of each matching line.