Script started on Mon Sep 14 17:30:47 2026
macbook:Desktop> cat q4
What is the command to compile the C program hello.c?
macbook:Desktop> cd csc3320_Fall2026/programs/C_ch2 
macbook:C_ch2> cat io_example.c
/* 
  hello world

  gcc io_example.c -o io_example

*/

#include <stdio.h>

int main (int argc, char *argv[]) {

   int n;

   printf("hello.\n");   // in-line comment
   scanf("%d", &n);
   printf("the number is %d\n", n); 

   return 0;
}
macbook:C_ch2> gcc io_example.c -o io_example
macbook:C_ch2> ./io_example 
hello.
9
the number is 9
macbook:C_ch2> cat io_example2.c 
/* 
  hello world

  gcc io_example2.c -o io_example2

*/

#include <stdio.h>

#define  num   4

int main (int argc, char *argv[]) {

  int n;

  printf("hello. Enter a number: ");   // in-line comment
  scanf("%d", &n);
  if (n < num)
    printf("the number is %d less than %d\n", n, num); 
  else
    printf("the number is %d greater than or equal to %d\n", n, num); 

  return 0;
}
macbook:C_ch2> gcc io_example2.c -o io_example2
macbook:C_ch2> ./io_example2
hello. Enter a number: 8
the number is 8 greater than or equal to 4
macbook:C_ch2> ./io_example2
hello. Enter a number: 3
the number is 3 less than 4
macbook:C_ch2> cat sizeof.c 
#include <stdio.h>

int main (int argc, char *argv[]) {

   printf("Size of a float is %d\n", sizeof(float)); 

   return 0;
}
macbook:C_ch2> gcc sizeof.c -o sizeof
sizeof.c:5:38: warning: format specifies type 'int' but the argument has type 'unsigned long' [-Wformat]
    5 |    printf("Size of a float is %d\n", sizeof(float)); 
      |                               ~~     ^~~~~~~~~~~~~
      |                               %lu
1 warning generated.
macbook:C_ch2> cat sizeof.c          
#include <stdio.h>

int main (int argc, char *argv[]) {

   printf("Size of a float is %lu\n", sizeof(float)); 

   return 0;
}
macbook:C_ch2> gcc sizeof.c -o sizeof
macbook:C_ch2> ./sizeof
Size of a float is 4
macbook:C_ch2> cat ~/Desktop/q5
T/F: A directive is a command to be executed when the program runs.
macbook:C_ch2> exit

Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.
Deleting expired sessions...      10 completed.

Script done on Mon Sep 14 19:03:29 2026