#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/unistd.h>


#define MEM_SIZE  (64*1024)   // 64k bytes
#define MY_KEY    0xBAD02152  // Arbitrary key to "name" memory segment
#define MY_ADDR   0x42000000  // Where we suggest the memory to be mapped

int main(int args, char* argv) {
  
  char line[256];

  int mem_handle;
  int i,j,l,err;

  char* mem_area;
  char c;

  fprintf(stderr,"Reader PID=%d\n",getpid());

  // Lookup segment with specific key.  Size and flags are not used
  mem_handle = shmget(MY_KEY,0, 0);

  if (mem_handle==-1) {
    fprintf(stderr,"Memory [key=%08X] could not be found: ", MY_KEY);
    perror(0);  // Print out specific error in errno
    exit(1);
  }

  // Map segment into this address space
  mem_area = (char*) shmat(mem_handle,(void*)MY_ADDR,0);

  if (mem_area==(char*)-1) {
    fprintf(stderr,"Could not attach [addr=%08X]: ",MY_ADDR);
    perror(0);  // Print out specific error in errno
    exit(1);
  }

  fprintf(stderr,"Reader memory segment mapped to %08x\n",mem_area);

  while (1) {
 
    // Read line of lenght up to 256 bytes
    for (l=0; l < 256; l++) {
      c = getchar();
      if (c==EOF || c=='\n') break;
      line[l] = c;
    }

    fprintf(stdout,"[%s]\n",mem_area);  // Pick up string in mem_area
    fflush(stdout);

  }
    
  exit(0);
}