信号处理程序不能跨不同的进程组工作

Question

我在使用fork创建的子项下使用execp我为其设置了新的进程组并使用tcsetpgrp设置了前台进程组

以下是main

的代码

int main()
{
    signal(SIGINT,SIG_IGN);
    signal(SIGTSTP,SIG_IGN);
    pid_t pid=fork();
    if(pid==-1)
    {
        perror("Error in forking");
    }
    else if(pid == 0)
    {
        signal(SIGTTOU, SIG_IGN);
        setpgid(getpid(),getpid());
        //check denotes if process needs to be run in background or not
        if(!check)
        {
            tcsetpgrp(STDOUT_FILENO,getpgid(getpid()));
            tcsetpgrp(STDIN_FILENO,getpgid(getpid()));
        }
        signal(SIGTSTP, tstphandler);
        signal(SIGINT,inthandler);
        if(strlen(token)>0)
        {
            execer=execlp(token,token,args,(char*)NULL);
            if (execer==-1)
            {
                printf("Error in execution);
            }
            exit(0);
        }

    }
    else
    {
        //processes is a data structure which contains pid of    
        //processes and current status :- 0 = running in background                  
        //, 1= dead , 2 = stopped in background , -1= in foreground.
        if(check)
        {
            processes[pid_counter].pid=pid;
            processes[pid_counter].dead=0;
        }
        if(!check && strlen(token)>0)
        {
            processes[pid_counter].pid=pid;
            processes[pid_counter].dead=-1;
            waitpid(pid,&status,0);
            tcsetpgrp(STDOUT_FILENO,globalpgid);
            tcsetpgrp(STDIN_FILENO,globalpgid);
            processes[pid_counter].dead=1;
        }
    }
}

这些是我的处理程序

//SIGINT handler
void inthandler(int sig)
{
    printf("int handler\n");
    int i;

    for(i=0;i<=pid_counter;i++)
    {
        if(processes[i].dead==-1)
        {
            kill(processes[i].pid,SIGKILL);
            break;
        }
    }
}

//SIGTSTP handler
void tstphandler(int sig)
{
    int i;
    for(i=0;i<=pid_counter;i++)
    {
        if(processes[i].dead==-1)
        {
            processes[i].dead=2;
            kill(processes[i].pid, SIGSTOP);
            break;
        }
    }
    tcsetpgrp(STDOUT_FILENO,globalpgid);
    tcsetpgrp(STDIN_FILENO,globalpgid);
}

我的问题是没有从子进程调用这些信号处理程序。使用默认操作调用它们，但不使用我声明的处理程序。