Which of the following commands or sequences of commands will rename a file x to file y in a unix system?

I. mv y,x
II. mv x,y
III. cp y, x(rm x)
IV. cp x, y (rm x) 

A student wishes to create symbolic links in a computer system running Unix. Three text files named "file 1", "file 2" and "file 3" exist in her current working directory, and the student has read and write permissions for all three files. Assume that file 1 contains information about her hobbies, file 2 contains information about her friends and file 3 contains information about her courses. The student executes the following sequence of commands from her current working directory

ln -s file 1 file 2
ln -s file 2 file 3 

Which of the following types of information would be lost from her file system?

(I) Hobbies (II) Friends (III) Courses

A user level process in Unix traps the signal sent on a Ctrl-C input, and has a signal handling routine that saves appropriate files before terminating the process. When a Ctrl-C input is given to this process, what is the mode in which the signal handling routine executes?

The contents of the text file t1.txt containing four lines are as follows:

a1 b1
a2 b2
a3 b2
a4 b1 

The contents of the text file t2.txt containing five lines are as follows:

a1 c1
a2 c2
a3 c3
a4 c3
a5 c4 

Consider the following Bourne shell script:

awk - F''' {Print S1, S2} ' t1.txt |
while read a b ; do
            awk -v aV = Sa - v bV = Sb - F''
            'aV = = S1 (print aV, bV, S2 )'t2.txt
done 

Which one of the following strings will NOT be present in the output generated when the above script in run? (Note that the given strings may be substrings of a printed line.)