Unix, show output

Example code to help continue:

#include #include #include #include #include #include

int readValue(); void writeValue(int i);

int main () { int i = 5432; char buffer[10];

int fd = open("number.dat", O_CREAT | O_TRUNC | O_WRONLY); int byteNum = sprintf(buffer, "%d", i);

write(fd, buffer, byteNum);

close (fd);

int j; char buffer2[10]; int fd2 = open("number.dat", O_RDONLY); read(fd2, buffer2, 10); j = atoi(buffer2); close(fd2);

printf("number read: %d ", j);

return 0;

}

Implement a program that will communicate the value of an integer x, between processes. You can do this using a file to store the value of x, or you can use shared memory with shmget or mmap. Shared memory is out of the scope of this class, so you rill have to teach yourself how to use it, however if you put in the effort to leari, it results in simpler more elegant code. x will start with the value 19530, and you must print that value. Then you will loop 5 times where in each loop: the child goes first and subtracts 5 from x, the parent then divides x by 5, and both processes print who they are and their result of x after the opcration. If you use a file and not shared memory, then during each iteration of the loop both processes must get the value of x from the file, and store the resulting value of x to the file. wait() is a required function call, so you will need to create a new process, and terminate it each time through the loop. The following system calls are required for this lab: fork() wait lhe following functions may be useful for this lab open) read), write) sleep) make the process wait for a number of seconds atoi () : converts string to integer sprintf ca be used to convert integer to string fflush(): forces a file buffer to flush. This is useful to flush stdout before creating a child so you don't have two processes printing the same buffer to the screen. This can sometimes fix strange printing bchavior The following is an example of what you will output to the screen