Systems Programming - Assignment Example

If you have not completed the work by the due date please hand in whatever you have done. 1. If I am currently in a directory /usr/jbloggs which currently contains just one file called file1 and nothing else. I want to put a copy of the file with the same name in a directory /usr/jbloggs/sub1/sub2 and another copy of the file called file2 in a directory /usr/jbloggs/sub1/sub3/sub4. List the commands you would need to do (in the correct order) to achieve this. 2. Explain what each of the components of the protection string lrwxr-xr-- which is on a file file3 means.

Give command(s) to change the file's protection to lrwx--x--- using the alphabetic form of the protection command and a second to change it from that to lrwxrwxr-- using the numeric form of the command. The first character 'l' denotes a Symbolic link. A symbolic link contains the name of the file to which it is linked. Symbolic links are created with the ownership of the creator and the permissions are of the creator's current umask. Once created, the symbolic link ownership and permissions will not change, because the mode and ownership of the symbolic link is ignored by the system.

Therefore, using CHMOD command, it is possible only to change the permission of the target file but not the link file itself. Therefore, it is not possible to change the permission of the link file as asked in this question.3. Write a fully commented Bourne shell script program that takes exactly two parameters and if both exist as files it appends the first file onto the end of the second. If either parameter is not a valid file the program will output an error message. Note - code with few or no comments will gain very few marks regardless of the quality of the code itself.

Marks will also be given for clarity and ease