The GREP Command in unix

The "grep" command allows you to search one file or multiple files for lines that contain a pattern.
Exit status is 0 if matches were found, 1 if no matches were found, and 2 if errors occurred.


Syntax for the grep command is:


grep [options] pattern [files]


options:


-w Match whole word.
-b Display the block number at the beginning of each line.
-c Display the number of matched lines.
-h Display the matched lines, but do not display the filenames.
-i Ignore case sensitivity.
-l Display the filenames, but do not display the matched lines.
-n Display the matched lines and their line numbers.
-s Silent mode.
-v Display all lines that do NOT match.


Example:


 grep -v in out.txt


output:
It displays the lines from the out.txt, which the "in" text is not presented.