0x0A-argc_argv

0x0A. C - argc, argv

Learning objectives for this project:

• How to use arguments passed to your program
• What are two prototypes of main that you know of, and in which case do you use one or the other
• How to use __attribute__((unused)) or (void) to compile functions with unused variables or parameters

Tasks 📃

• 0. It ain't what they call you, it's what you answer to

  • 0-whatsmyname.c: C program that prints its name, followed by a new line.
    • If you rename the program, it will print the new name, without having to compile again
    • You should not remove the path before the name of the program

• 1. Silence is argument carried out by other means

  • 1-args.c: C program that prints the number of arguments passed into it, followed by a new line.

• 2. The best argument against democracy is a five-minute conversation with the average voter

  • 2-args.c: C program that prints all the arguments it receives.
    • All arguments are printed, including the first one.
    • One argument per line.

• 3. Neither irony nor sarcasm is argument

  • 3-mul.c: C program that multiplies two numbers.
    • Prints the result followed by a new line
    • Assume two numbers and result are stored as integers
    • Print Error and return 1 if program does not receive two arguments

• 4. To infinity and beyond

  • 4-add.c: C program that adds two positive numbers and prints the result, followed by a new line.
    • The program assumes that the numbers and result of the addition can be stored in an int.
    • If no number is passed to the program, it prints 0 followed by a new line.
    • If one of the numbers contains symbols that are not digits, the program prints Error followed by a new line and returns 1.

• 5. Minimal Number of Coins for Change

  • 100-change.c: C program that prints the minimum number of coins to make change for an amount of money.
    • Usage: ./change cents where cents is the amount of cents needed to give back.
    • Change can use an unlimited number of coins of values 25, 10, 5, 2 and 1 cent.
    • If the number passed as the argument is negative, the program prints 0 followed by a new line.
    • If the number of arguments passed to the program is not exactly one, it prints Error followed by a new line and returns 1.