# Operating System

QUESTION 4 [18 Marks) (a) Figure 4 depicts a part of directory structure for a workstation. Consider a command prompt console is using the UNIX command line and the current working directory is music folder. Answer the following questions: example-site index.html activities indoor camping.html index.html outdoor basketball.html index.html swim.html CSS style.css images logo.png music hiphop.html index.html rnb.html theater index.html listings.html reviews.html Figure 4 i. In the current directory, write a single command line to copy the style.css into the images folder. [2] ii. In the current directory, write TWO different ways of single command line to set the access control of its files so that all classes can be write only. [3] (b) Indicate whether statements below are TRUE or FALSE statements, according to the Unix files access control as shown in Figure 5. [4] -rwxr--r-x Shafoora Shafoora 2.6K Dec 16 2020 File123 -rw-r-xr-x Chowdry Student 436B Aug 28 2020 README drwxrwxr-x Barongobi Student 1973 Aug 28 2020 Notes Figure 5 i. Untitled and README are directory. ii. README group access right is read only. File123 file can be edited by Shafoora. iv. Notes is a folder that is shared among Student group. (c) Given the following information: A disk drive with 200 cylinders; A request queue: 98, 149, 37, 122, 14, 124, 65, 67 Head pointer 25 Direction: the disk arm is moving to innermost. i. By using the C-LOOK disk scheduling algorithms, illustrates by drawing the movement of the disk arm to satisfy the requests. Label clearly. [7] ii. Calculate the total distance (in cylinders) that the disk arm moves to satisfy the requests. Show your working. [2] QUESTION 4 [18 Marks) (a) Figure 4 depicts a part of directory structure for a workstation. Consider a command prompt console is using the UNIX command line and the current working directory is music folder. Answer the following questions: example-site index.html activities indoor camping.html index.html outdoor basketball.html index.html swim.html CSS style.css images logo.png music hiphop.html index.html rnb.html theater index.html listings.html reviews.html Figure 4 i. In the current directory, write a single command line to copy the style.css into the images folder. [2] ii. In the current directory, write TWO different ways of single command line to set the access control of its files so that all classes can be write only. [3] (b) Indicate whether statements below are TRUE or FALSE statements, according to the Unix files access control as shown in Figure 5. [4] -rwxr--r-x Shafoora Shafoora 2.6K Dec 16 2020 File123 -rw-r-xr-x Chowdry Student 436B Aug 28 2020 README drwxrwxr-x Barongobi Student 1973 Aug 28 2020 Notes Figure 5 i. Untitled and README are directory. ii. README group access right is read only. File123 file can be edited by Shafoora. iv. Notes is a folder that is shared among Student group. (c) Given the following information: A disk drive with 200 cylinders; A request queue: 98, 149, 37, 122, 14, 124, 65, 67 Head pointer 25 Direction: the disk arm is moving to innermost. i. By using the C-LOOK disk scheduling algorithms, illustrates by drawing the movement of the disk arm to satisfy the requests. Label clearly. [7] ii. Calculate the total distance (in cylinders) that the disk arm moves to satisfy the requests. Show your working. [2]