Script started on Fri Sep  9 12:18:45 2022
cascade:c++files> cat hello_example.c
/* 
  hello world
*/

#include <stdio.h>

int main () {

   printf("hello world.\n"); 

   return 0;
}
cascade:c++files> gcc hello_example.c -o hello_example
cascade:c++files> ./hello_example
hello world.
cascade:c++files> 
cascade:c++files> cat switch_example.c
/* 
   Simple example showing a switch statement
   -MCW Sept. 2022
*/

#include <stdio.h>   

int main () {

  // Go through all possibilities
  for (int number=0; number<4; number++) {
    switch (number) {
      case 0:
        printf("Zero\n");
        break;
      case 1:
        printf("One\n");
        break;
      case 2:
        printf("Two\n");
        break;
      default:
        printf("Expecting number to be 0, 1, or 2.\n");
      }
    }

    return 0;
}
cascade:c++files> gcc switch_example.c -o switch_example
cascade:c++files> ./switch_example
Zero
One
Two
Expecting number to be 0, 1, or 2.
cascade:c++files> 
cascade:c++files> 
cascade:c++files> cat scanf_example.c
/* 
   Simple example showing a scanf statement (user input)
   -MCW Sept. 2022
*/

#include <stdio.h>   

int main () {

  int number;

  // Give a prompt, so the user knows what to do.
  printf("Enter an integer: ");

  // "%d" says that we want a decimal number (integer)
  // The ampersand is important, and we'll talk about it in detail.
  scanf("%d", &number);

  // Just use number normally here, without the ampersand.
  printf("You entered %d \n", number);

  return 0;
}
cascade:c++files> gcc scanf_example.c -o scanf_example
cascade:c++files> ./scanf_example 
Enter an integer: 3
You entered 3 
cascade:c++files> ./scanf_example 
Enter an integer: 54321
You entered 54321 
cascade:c++files> ./scanf_example 
Enter an integer: -98.7
You entered -98 
cascade:c++files> ./scanf_example 
Enter an integer: I am not following directions
You entered 180969526 
cascade:c++files> 
cascade:c++files> 
cascade:c++files> 
cascade:c++files> ls -l rand*.c
-rw-r--r--  1 mweeks  staff  6588 Nov 24  1992 rand.c
-rw-r--r--  1 mweeks  staff  1069 Sep  9 12:06 random_example.c
cascade:c++files> 
cascade:c++files> cat random_example.c
/* 
   Simple random number example
   -MCW Sept. 2022
*/

#include <stdio.h>   // input, output
#include <stdlib.h>  // for random, srandom
#include <math.h>    // for floor function
#include <time.h>    // for time function

int main () {

    // Call srandom to "seed" the random number generator.
    // See
    // https://stackoverflow.com/questions/16569239/how-to-use-
    //   function-srand-with-time-h
    // for more detail about srandom and time.
    // Basically, time returns a different value each time we run it.
    // Use it to give us a non-predictable sequence of random numbers.
    unsigned int mytime;   
    // get the current time
    mytime = time(NULL);

    // Seed the random number generator
    srandom(mytime);
 
    // random() returns a long integer.
    // Make sure to use random() instead of rand().
    // Use % (modulus) to reduce it to something manageable, 
    // in this case < 100.
    long r1 = random() % 100;

    // %li is for a long integer. %ld works too.
    printf("A random integer is %li.\n", r1);

    return 0;
}
cascade:c++files> gcc random_example.c -o random_example
cascade:c++files> ./random_example 
A random integer is 26.
cascade:c++files> ./random_example 
A random integer is 91.
cascade:c++files> ./random_example 
A random integer is 72.
cascade:c++files> exit
exit

Script done on Fri Sep  9 12:21:59 2022