A bash script is a file containing bash commands. We must first take the following two steps to make the file executable.$$

$1.$ The script file should contain the following code as its very first line: #$!/$bin$/$bash

This specifies which program bash should be used to interpret the commands in the script.

$$Next$,$ the script's file permissions should be set to be executable. Recall that this is typically done as follows: chmod $+$x scriptname

The script can then be run like any other executable file: $./$scriptname

Actually, we can also run a script as follows, even without making the script executable, but this is less frequently done.

bash scriptname

Question $1$:

Write a script that takes a file name as command$-$line input and counts the number of lines in the file. You can use the$$wc$$command with the$-$l$$options to count the number of lines in the file. You can use the above$-$mentioned command$-$line variables to get the filename $($assume the filename does not have any spaces$).$ Use command substitution$(`$$$($command$)`)$to capture the output of the$$wc$$command and store it in a variable.$$

Question $2$:

Write a script that takes a directory name as command$-$line input and creates a backup of all the files in the directory. You can use the$$mkdir$$command to create a new directory with a unique name $($for example, using the current date and time$).$ You can use the$$cp$$command to copy all the files from the input directory to the new directory and the$$tar$$command to compress the new directory into an archive. Finally, you can use the$$rm$$command to delete the new directory to clean up$.$