Chapter $8,$ Lab $2$: Shell Parameters and Variables

$(15$ Minutes$)$

Learning Objectives and Outcomes

In this lab you will learn about user$-$ereated variables and keyword variables.

Reading

Read "Paramesers and Variables" oe page $300$ of Sobell up to "Pultantue expansion in assigements" en page $303.$

Procedure

Although variables are mostly wed in scripts and read by poograms, you cale experiment witl them on the command line.

Assign your mame to the variable samed myname and we acho bo display the value of my name when it is uaquosed, quoted

using double quotabioe marks, and quoted using single quotiatice maiks.

$($Refer to "Parameter sabstitution" in Sobell and "Quoting the $ $"($Sobell$)$

Use the readonly $($Sobell$,$ page $305)$ built$-$in to make the myname variable you crealed in the pecvious step a readonly variable

and then assign a atew value to it$.$

What happens?

What is the value of your HOMF. $($Sobell$)$ keyword variable?

Demoestrate that the tilde $($; Sobelli$)$ holds the same value as HOME.

List the conients of your lome directory using a tilde.

The PATH $($Sobell$)$ beyword variable specifies the directories in the order bach should search them when it searches bor a

script of program you run from the command line.

What is the value of your PATH variable?

The date $($Sobell$)$ utility displays the dane and time.

Write asd execule a shell scrips that doplays the dase and time, the antse of your bome directory, and the value of your PATH

variable.