很奇怪：在redhat下能出结果，ubuntu就不行

[Rainy.mayday]

代码： 全选

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#define  MSGKEY 75
struct msgform
{   long mtype;
    char mtext[256];
 };

main(int argc,char *argv[])
{ struct msgform msg;
  int msgqid, pid, *pint;

  msgqid = msgget(MSGKEY,0777|IPC_CREAT);
  printf("msgqid = %d\n\n",msgqid);

  pid = getpid();
  pint = (int *)msg.mtext;
  *pint = pid;
  msg.mtype = 1;
  msgsnd(msgqid,&msg,sizeof(int),0);

  msgrcv(msgqid,(struct msgform *)&msg,sizeof(msg),pid,0);
  pint = (int*)msg.mtext;
  pid = (int)*pint; 
  printf("Client %s: receive from Server process %d\n",argv[1],pid);
}

代码： 全选

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#define  MSGKEY 75
struct msgform
 {  long mtype;
    char mtext[256];
 };
int msgqid;

main()
{ struct msgform msg; 
  int i,*pint;
 int pid;
  extern cleanup();
  for (i=0;i<20;i++) 
    signal(i,cleanup);
  msgqid = msgget(MSGKEY,0777|IPC_CREAT);
  printf("msgqid = %d\n\n",msgqid);  
  for(;;)
  {
   msgrcv(msgqid,(struct msgform *)&msg,256,1,0);
   pint = (int *)msg.mtext;
   pid = (int)*pint;
   printf("Server : receive from Client process %d \n\n",pid);
   msg.mtype = pid;
   pint = (int *)msg.mtext;
   *pint = getpid();
   msgsnd(msgqid,&msg,sizeof(int),0);
  }
}

cleanup()
 { msgctl(msgqid,IPC_RMID,0);
  exit(0);
 }

代码： 全选

#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
main()
{ int  pid1,pid2,pid3;
  pid1 = vfork();
  if (pid1 == 0)
   {  printf("\nClient1 process %4d :\n",getpid());
     execlp("/home/student/client","client","1",NULL);
    } 
  else
    { pid2 = vfork();
      if (pid2 == 0)
       {   printf("Client2 process %4d:\n",getpid()); 
          execlp("/home/student/client","client","2",NULL);
       }
      else
       { pid3 = vfork();
         if (pid3 == 0)
         { printf("Server3 process %4d:\n",getpid());
           execlp("/home/student/server","server",NULL);
         }
         else
           printf("\nThis is Parent process %4d ! \n\n",getpid()); 
        }
     }
  wait(0);
  wait(0);
  wait(0);
 }

我们操作系统上机写的代码，自己回来在ubuntu下编译可以通过，但是运行的时候显示
：
Client1 process 18814 :
Client2 process 18815:
msg: cxa_atexit.c __new_exitfn: Assertion `l != ((void *)0)' failed.
Aborted

上机的时候（redhat）：

[student@localhost ~]$ ./msg



Client1 process 19083 :

msgqid = 65536



Client2 process 19084:

msgqid = 65536



Server3 process 19085:



This is Parent process 19082 !



msgqid = 65536



Server : receive from Client process 4788



Server : receive from Client process 19083



Client 1: receive from Server process 19085

Server : receive from Client process 19084



Client 2: receive from Server process 19085
这是为什么呢？

[zheng1733]

我看不懂。
但是这两句，“ execlp("/home/student/client","client","1",NULL);”， execlp("/home/student/server","server",NULL);
说明机房的redhat上有student这个用户，但是，你的ubuntu下有student这个用户吗？