/*
 * Write a string to a shared memory segment of 512 bytes
 * New File Mar 22,1989
 * Author   Jerry LeVan
 *
 */
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

#define SIZE	512		/* shared memory buffer size */
#define KEY		'JHL '	/* our key */


main()
{
  key_t key;
  int memoryid;
  char * location;

  /* the shmget will fail if the segment has not been created */
  memoryid = shmget(KEY,SIZE,0);
  printf("status of key retrival = %d\n",memoryid);
  if(memoryid == -1) {perror("Bad Key");exit();}

  /*
	 we got the key now attach to the segment 
     we will allow the system to chose the location (second parm)
	 and we will want read/write access (third parm)
  */
  location = (char *)shmat(memoryid,0,0);  /* we want read write access */
  printf("status of attach = %d\n",location);
  if (location == (char*)-1) {perror("Bad Attach");exit();}

  /* memory has been attached to,now copy string into the location */
  printf("Enter string -> ");
  gets(location);
  printf("location contains: %s\n",location);
 }