List the names of all the files in the $/$usr$/$bin directory that has $$as$$ in them and count how many of them there are.

Question $2[3$ marks$].$

List the names of all the files in the $/$usr$/$bin directory that start with an uppercase letter and count how many of them there are.

Question $3[3$ marks$].$

List the names of all the files in the $/$usr$/$bin directory that start with an uppercase letter and end with a number and count how many of them there are.

Question $4[3$ marks$].$

List the names of all the files in the $/$usr$/$bin directory that consist of $6$ letters, where the $2$nd letter must be $$a$$ or $$b$$ or $$c$$ and count how many of them there are.

Question $5[3$ marks$].$

List the names of all the files in the $/$usr$/$bin directory that start and end with a vowel and have a total of filename length of only $3$ characters and count how many of them there are.

Exercise $2$: Working with file permissions.

Initial setup:

Create two new directories: cosc$-$dir$1$ and cosc$-$dir$2.$ Using the touch command create five files file$1$ file$5$ in both directories.

Question $6-$ use Symbolic Notation to change file permissions. $[2$ marks each$].$

a$)$ The file $$file$1$ should be executable only by the owner, and neither readable nor writable by anyone.

b$)$ The file $$file$2$ should be readable and executable by you and others, but not by members of your group.

c$)$ The file $$file$3$ should have write permissions enabled for you and your group, read permissions disabled for all, and should only be executable by others.

d$)$ The file $$file$4$ should be readable and writable by you and others, but not by members of your group.

e$)$ The file $$file$5$ should be readable and writable only by members of your group, not by you or others.

In the cosc$-$dir$1$ directory, take a screenshot the output by executing the command ls $-$l$.$

Question $7$ use Octal Notation to change file permissions. $[2$ marks each$].$

Repeat Question $6$ for the files in your cosc$-$dir$2$ directory but use the chmod command with octal notation.

In the cosc$-$dir$2$ directory, take a screenshot the output by executing the command ls $-$l$.$