testcop.c

/**
 * By:  Niko Tubach
 *      Brandon Ashley
 *      Lucas Rosa
 *  COP4600 - Assignment 5
*/
#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<fcntl.h>
#include<string.h>

#define BUFFER_LENGTH 1500               /// The buffer length
static char receive[BUFFER_LENGTH];     /// The receive buffer

int main(){
   int ret, fd;
   char stringToSend[BUFFER_LENGTH];
   printf("Starting device test code example...\n");
   fd = open("/dev/copchar", O_RDWR);             // Open the device with read/write access
   if (fd < 0){
      perror("Failed to open the device...");
      return errno;
   }
   printf("Type in a short string to send to the kernel module:\n");
   scanf("%[^\n]%*c", stringToSend);                // Read in a string (with spaces)
   printf("Writing message to the device '%s'.\n", stringToSend);
   ret = write(fd, stringToSend, strlen(stringToSend)); // Send the string
   if (ret < 0){
      perror("Failed to write the message to the device.");
      return errno;
   }

   printf("Press ENTER to read back from the device...\n");
   getchar();

   printf("Reading from the device...\n");
   ret = read(fd, receive, BUFFER_LENGTH);        // Read the response from the LKM

   if (ret < 0){
      perror("Failed to read the message from the device.");
      return errno;
   }
   printf("The received message is: '%s'\n", receive);
   printf("End of the program\n");
   return 0;
}