Shell Scripts (Linux):

1) Write a shell script called calculate that will take three command line arguments: a mathematical operand ('+' or '-' or '*' or '/') and two integers. The script must display an error if it is run without an argument. The script will then perform the mathematical operation given by the command line argument (addition, subtraction, multiplication or division) on those two numbers. The script will then print the results of the operation to the screen and exit. Hint: since * is a bash metacharacter, you will need to escape in in your script, e.g. put \* Do not use a read command, your user should put these in as command line arguments. The correct syntax should be calculate

2) Write a shell script called gotmail that will check for the existence of a mail spool file (see environment variable MAIL). If the file exists the script will print the following to the screen: "You have a mail spool file." If the file does not exist, the script will print nothing. Assume the script returns its result for the user who runs it, don't hard code the user.