Regular Expressions

The options can be as follows:

-i          Ignore upper/lower case distinction in during comparisons.

-n         Precede each line through its line number in the file (first line is 1).

-c         Print only a count of the lines which contain the pattern.

-l          Print only the names of files with matching lines, separated through NEWLINE characters. Don't repeat the names of files when the pattern is found more than once.

-v         Print all lines except those which contain the pattern.

Let consider the file stud_rec with the following data

# cat stud_rec

Anjana             23        UC++ Annanagar

Divya              19        UC++ Padi

Farida              26        DBA   T.Nagar

Prashant          22        UNIX Admin

Kilpauk Rahul 21        ORVB Shenoy Nagar

Fardeen           27        DBA Adayar

The students who are taking UCC++ course can be shown by using the grep as follows:

# grep UC++ stud_rec

Anjana 23        UC++ Annanagar

Divya  19        UC++ Padi