Project $3-7$

ESTIMATED TIME: $30$ minutes

OBJECTIVE: Use regular expressions.

DESCRIPTION: In this hands$-$on project, you use the grep and egrep commands alongside regular expression metacharacters to explore the contents of text files.

$1$

Switch to a command$-$line terminal $($tty$5)$ by pressing Ctrl$+$Alt$+$F$5$ and log in to the terminal using the user name of root and the password of LINUXrocks!.

$2$

At the command prompt, type grep "Inn" sample$1$ and press Enter. What is displayed?

$3$

At the command prompt, type grep $-$v "Inn" sample$1$ and press Enter. What is displayed?

$4$

At the command prompt, type grep "inn" sample$1$ and press Enter. What is displayed and why?

$5$

At the command prompt, type grep $-$i "inn" sample$1$ and press Enter. What is displayed?

$6$

At the command prompt, type grep "I" sample$1$ and press Enter. What is displayed?

$7$

At the command prompt, type grep $"$ I $"$ sample$1$ and press Enter. What is displayed?

$8$

At the command prompt, type grep $"$t$.$e$"$ sample$1$ and press Enter. What is displayed?

$9$

At the command prompt, type grep $"$w$...$e$"$ sample$1$ and press Enter. What is displayed?

$10$

At the command prompt, type grep $"^$I" sample$1$ and press Enter. What is displayed?

$11$

At the command prompt, type grep $"^$I $"$ sample$1$ and press Enter. What is displayed?

$12$

At the command prompt, type grep $"($we$|$next$)"$ sample$1$ and press Enter. What is displayed? Why?

$13$

At the command prompt, type egrep $"($we$|$next$)"$ sample$1$ and press Enter. What is displayed?

$14$

At the command prompt, type grep "Inn$$"$ sample$1$ and press Enter. What is displayed?

$15$

At the command prompt, type grep $"?$$$"$ sample$1$ and press Enter. What is displayed and why? Does the $?$ metacharacter have special meaning here? Why?

$16$

At the command prompt, type grep $"^$$$"$ sample$1$ and press Enter. Is anything displayed? $($Hint: Be certain to look closely!$)$ Can you explain the output?

$17$

Type exit and press Enter to log out of your shell.