n this Lab, you need to finish the following tasks$\mathrm{.}1.$ Download $$FileIO$.$c$$ and $$input$.$txt$$ from BlackBoard, and store them in the same directory$\mathrm{.}2.$ Compile and run $$FileIO$.$c$$ using the following commands:gcc FileIO.c $-$o FileIO.$/$FileIO$3.$ Modify $$FileIO$.$c$$ and rename it using your last name to meet the following requirements:$$ If the character in $$input$.$txt$$ is a lower$-$case letter, your program converts it into anupper$-$case letter and write it to $$output$.$txt$.$ If the character in $$input$.$txt$$ is an upper$-$case letter, your program converts it into alower$-$case letter and write it to $$output$.$txt$.$ If the character in $$input$.$txt$$ is not a letter, your program just writes it to $$output$.$txt$$without change.$$ Your program should also check the number of command$-$line arguments. If more thanone command$-$line argument are provided, your program should print $$This program doesnot allow more than one command$-$line argument!$$ on the screen, and exit immediately.For example, if you run your program as follows:.$/$Your$\_$LastName $1$Since there are two command$-$line arguments $($i$.$e$.,./$Your$\_$LastName$$ and $1)$ in theabove example, your program should print $$This program does not allow more than onecommand$-$line argument!$$ on the screen, and exit immediately without accessing thefiles$\mathrm{.}4.$ Compile and run your modified program.