OPERATING SYSTEMS LABORATORY III - C Review II

1. Structures; a set of more variables grouped together for convenient handling.
   • http://siber.cankaya.edu.tr/OperatingSystems/cfiles/code10.ccode10.c

     #include <stdio.h>
     #define PI 3.14
     typedef struct point {
       int x;
       int y;
     } Point;
     typedef struct circle {
       Point center;
       int radius;
     } Circle;
     double get_area(Circle *c);
     int main(int argc, char *argv[])
     {
       Point p;
       p.x = 3;
       p.y = 5;
       Circle *circle = (Circle *)malloc(sizeof(*circle));
       circle->center = p;
       circle->radius = 2;
       printf("center: (%d, %d), radius: %d)\nArea: %f\n",
       circle->center.x,circle->center.y,circle->radius, get_area(circle));
       return 0;
     }
     double get_area(Circle *c)
     {
       return 2*PI*c->radius;
     }
     

   • Analyze the code.
   • Execute the code. What is the output and why?
   • Exercise: Modify the code to;
     • add structure for a cylinder,
     • print out the volume of the cylinder.
2. File Input and Output; examples on how to read from a file and write to a file.
   • http://siber.cankaya.edu.tr/OperatingSystems/cfiles/code11.ccode11.c and http://siber.cankaya.edu.tr/OperatingSystems/cfiles/code12.ccode12.c.
   • Analyze the code11.c and the output, do not forget to retrieve the file http://siber.cankaya.edu.tr/OperatingSystems/cfiles/datafiledatafile.
   • Analyze the code12.c and the output, what is stored into file ``output''?