Shell Scripts

Part One Exercise (10 Marks) Create an interactive script called divtest that tests whether a user-specified number is divisible by two user-specified factors. The script will require that the two factors be specified by the user as integer command-line arguments. The script will prompt the user for the integer to test. To help clarify the requirements, consider the following example. Suppose 10 and 3 are the factors to be used in the test, and 21 is the integer to be tested. The user would run the command with the following command line, $ divtest 10 3 Then the script would prompt the user for the integer to test and the user would then provide the number 21 followed by pressing the <enter> key. Here is the way the script would run to completion (what the user would type is shown in bold): $ divtest 10 3 Enter an integer to test: 21 21 is divisible by 3. $ To give you a feel for the way the script should run under all conditions, here are 3 other sample runs (again, what the user would type is shown in bold): $ divtest 7 5 Enter an integer to test: 70 70 is divisible by 7. 70 is divisible by 5. $ $ divtest 10 12 Enter an integer to test: 33 33 is not divisible by 10 or 12. $ $ divtest 10 12 Enter an integer to test: 70 70 is divisible by 10. $ Your script should also handle the situation where the user forgets to specify the factors on the command line as follows: $ divtest Usage error: two, integer command-line arguments required. Try again. Exercise Two (10 marks) Create a script (that is not interactive) called drawBox that outputs a box of characters with dimensions specified by the user on the command line. When the user runs the command she/he would provide 4 command-line arguments as follows: • The first argument is an integer specifying the width of the box to be drawn. • The second argument is an integer specifying the height of the box to be drawn. • The third argument is a letter that is used to fill the odd numbered lines. • The fourth argument is a letter that is used to fill the even numbered lines. The sample runs below demonstrate how your script should run (what the user would type is shown in bold): $ drawBox Error: Invalid number of arguments - Enter 4 arguments on the command line. - enter 2 integers followed by two letters. $ drawBox 6 3 X O XXXXXX OOOOOO XXXXXX $ drawBox 6 3 O X OOOOOO XXXXXX OOOOOO $ drawBox 20 7 O X OOOOOOOOOOOOOOOOOOOO XXXXXXXXXXXXXXXXXXXX OOOOOOOOOOOOOOOOOOOO XXXXXXXXXXXXXXXXXXXX OOOOOOOOOOOOOOOOOOOO XXXXXXXXXXXXXXXXXXXX OOOOOOOOOOOOOOOOOOOO $ drawBox 10 1 O X OOOOOOOOOO $ drawBox 10 8 V M VVVVVVVVVV MMMMMMMMMM VVVVVVVVVV MMMMMMMMMM VVVVVVVVVV MMMMMMMMMM VVVVVVVVVV MMMMMMMMMM $ drawBox 20 9 o w oooooooooooooooooooo wwwwwwwwwwwwwwwwwwww oooooooooooooooooooo wwwwwwwwwwwwwwwwwwww oooooooooooooooooooo wwwwwwwwwwwwwwwwwwww oooooooooooooooooooo wwwwwwwwwwwwwwwwwwww oooooooooooooooooooo $