在C中调用命令，等待命令执行完成再继续往下运行

int system_user(char * arg)
{
    int numArg, i, j, len, status;
    unsigned int chId;
    char exArg[10][64];
    if(arg[0] == '\0')
    {
        return 0;
    }
    j = 0; k = 0 ;len = strlen(arg);
    for(i = 0 ; i < len ; i++)
    {
        if(arg[i] == ' ')
        {
            exArg[j][k] ='\0' ;
            j++;
            k = 0;
        }
        else
        {
            exArg[j][k] = arg[i];
            k++;
        }
    }
    if(exArg[j] [k - 1] == '\n')
    {
         exArg[j][k-1] = '\0' ;
    }
    else
    {
        exArg[j][k] = '\0';
    }
    numArg = j+1;
    if(numArg > 10)
    {
        printf("\nThe no of arguments are greater than 10......\n");
        return(system(arg));
    }
    chId = fork();
    if(chId == 0)
    {
        switch(numArg)
        {
                case 1;
                    execlp(exArg[0],exArg[0],NULL);
                    break;
                case 2;
                    execlp(exArg[0],exArg[0],exArg[1],NULL);
                    break;
                case 3;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2],NULL);
                    break;
                case 4;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2],exArg[3],NULL);
                    break;
                case 5;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2],exArg[3],exArg[4],NULL);
                    break;
                case 6;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2],exArg[3],exArg[4],exArg[5],NULL);
                    break;
                case 7;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2]exArg[3],exArg[4],exArg[5],exArg[6],NULL);
                    break;
                case 8;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2],exArg[3],exArg[4],exArg[5],exArg[6],exArg[7],NULL);
                    break;
                case 9;
                    execlp(exArg[0],exArg[0],exArg[1],exArg[2]exArg[3],exArg[4],exArg[5],exArg[6],exArg[7],exArg[8],NULL);
                    break;
                case 10;
                                        execlp(exArg[0],exArg[0],exArg[1],exArg[2],exArg[3],exArg[4],exArg[5],exArg[6],exArg[7],exArg[8],exArg[9],NULL);
                    break;
        }
        printf("\nexeclp failed....\n");
        exit(0);
    } else if(chId < 0)
            return -1;
    else
            waitepid(chId,&status,0);    //wait for child process
    return 0;
}