In Linux please: Variable Questions

Determine and use a command that will store the number $12$ into the variable num.

Write the command in your assignment, and explain the importance of the command.

What command will allow you to check the value of the variable num?

Write the command in your assignment.

Start a subshell by typing sh$.$ What is the current value for the variable you just created? Why is that so and what can

be done to remedy this? Write down the command, along with your answer as to why the variable did not show in the

subshell.

Executing a Script

For a script file to run in a Linux shell, what permissions must the file have?

Write down the command and options needed in your assignment.

Once a script has the permissions set, what are the three separate ways that would allow you to run that script? Which

way allows you to debug your script?

Scripting $-$ Develop scripts using the following problem sets. Be sure to use comments in your scripts. It may be helpful to

first write out the step by step process that you need to solve the problem BEFORE attempting to write the scripts. There

are examples in the PowerPoint lecture. Scripting $-$ Develop scripts using the following problem sets. Be sure to use comments in your scripts. It may be helpful to

first write out the step by step process that you need to solve the problem BEFORE attempting to write the scripts. There

are examples in the PowerPoint lecture.

Create a script that asks the user for a file and then appends the date to the file the user has entered. Let the user

know if the file can or cannot be written too. Also, if the file does not exist create the file and write the date in the

newly created file. Lastly display to the user the file, including a statement letting them know that the file has changed.

$($Hint: remember the $-f$ and $-w$ when evaluating a file in an if statement$)$

Create a script that takes two numbers as input from the user, and then asks the user if they would like to add or

subtract the two numbers $($use a case statement$).$ Then print out the result in a friendly message to the screen. Be sure

to let the user know if they choose an option that was not on the menu. $($Hint: when evaluating the inputted values from

the user, they must be represented as numerical data types.$)$ Now modify your case statement so the user can use either

an upper or lower case letter in the menu. That is if the user types a or A both will allow the case statement to run the

add selection. $($Hint: use $|$ as the or operator$)$

How to turn in$.$

After you have completed your lab, submit it here in Canvas

Variable Questions

Determine and use a command that will store the number $12$ into the variable num.

Write the command in your assignment, and explain the importance of the command.

What command will allow you to check the value of the variable num?

Write the command in your assignment.

Start a subshell by typing sh$.$ What is the current value for the variable you just created? Why is that so and what can be done to remedy this? Write down the command, along with your answer as to why the variable did not show in the subshell.

Executing a Script

For a script file to run in a Linux shell, what permissions must the file have?

Write down the command and options needed in your assignment.

Once a script has the permissions set, what are the three separate ways that would allow you to run that script? Which way allows you to debug your script?

Scripting $$ Develop scripts using the following problem sets. Be sure to use comments in your scripts. It may be helpful to first write out the step by step process that you need to solve the problem BEFORE attempting to write the scripts. There are examples in the PowerPoint lecture.

Create a script that asks the user for a file and then appends the date to the file the user has entered. Let the user know if the file can or cannot be written too. Also, if the file does not exist create the file and write the date in the newly created file. Lastly display to the user the file, including a statement letting them know that the file has changed.

$($Hint: remember the $$f and $$w when evaluating a file in an if statement$)$

Create a script that takes two numbers as input from the user, and then asks the user if they would like to add or subtract the two numbers $($use a case statement$).$ Then print out the result in a friendly message to the screen. Be sure to let the user know if they choose an option that was not on the menu. $($Hint: when evaluating the inputted values from the user, they must be represented as numerical data types.$)$ Now modify your case statement so the user can use either an upper or lower case letter in the menu. That is if the user types a or A both will allow the case statement to run the add selection. $($Hint: use $|$ as the or operator$)$