cli_max.c

lpc implement for distribut

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include "mymsg.h"

int   open_attach(char *,int);
int   door_call(int ,char *);
int   call_result(int);
int   door_msg_id=-1;
message *rcv_msg,
        *snd_msg;
int     rcv_len,
        snd_len;

int main(int argc,char **argv)
{
  int   fd;
  char  snd_str[2*MAXSIZE],
        chrtmp[20];;
  if (argc != 4)
  {
    error_quit("*****usage: client <client_pathname> <string1> <string2>*****");
    exit (1);
  }
  if ( strlen(argv[2]) > 20 || strlen(argv[3]) > 20)
  {
     error_quit("*****input is too long,try again(<=20******");
     exit (1);
  }
  fd = open_attach(argv[1],'1');
  strcpy(chrtmp,argv[2]);
  strcat(chrtmp,"+");
  strcpy(snd_str,chrtmp);
  strcat(snd_str,argv[3]);
  snd_str[strlen(snd_str)+1] ='\0';
  door_call(fd,snd_str);
  call_result(fd);
  exit (0);
}

int open_attach(char *pathname,int def)
{
  int door_id;
  door_id = ftok(pathname,def);
  door_msg_id = msgget(door_id,0);
  if (door_msg_id == -1)
  {
     error_quit("!!! get door error!!!\n");
     exit (1);
  }
  return (door_msg_id);
}

int door_call(int fd,char *ptr)
{
  int ret;
  int size;
  size = 2*sizeof(long) + strlen(ptr) +1;
  snd_msg=(message *)malloc(size);
  snd_msg->m_type = CLIENT_INPUT;
  snd_msg->process_id = getpid();
  strncpy(snd_msg->m_buf,ptr,strlen(ptr));
  snd_len = sizeof(long) + strlen(snd_msg->m_buf);
  if ((ret = msgsnd(fd,snd_msg,snd_len,0)) < 0)
  {
     error_quit("send message to server ");
     exit (1);
  }
  printf("<<<send a request to server----%s>>>\n",ptr);
  free(snd_msg);
  return (0);
}

int call_result(int fd)
{
  int  len;
  long type;
  rcv_msg =(message *)malloc(MAXSIZE+2*sizeof(long));
  type = getpid();
  if ((len = msgrcv(fd,rcv_msg,sizeof(rcv_msg)-sizeof(long),type,0)) < 0)
  {
     error_quit("!!!receive result error!!!\n ");
     exit (1);
  }
  printf("<<<the result from server is %s>>>\n",rcv_msg->m_buf);
  free(rcv_msg);
  return (0);
}