父进程

当shell脚本进程退出或返回到父进程时，退出码应该是0。

When a shell script process exits or returns to the parent process , the exit code should be0 .

在此例中，父进程调用fork，等待两秒钟，然后退出。

In this example , the parent process calls fork , waits for two seconds , then exits .

指向兄弟进程链表中下一个和前一个元素的指针，兄弟进程指的是与P有相同父进程的进程。

The pointers to the next and previous elements in the list of the sibling processes , those that have the same parent as P.

由于子进程在后台运行，父进程一终止，控制即返回到Shell。

Because the child process is running in the background , control returns to the shell as soon as the parent dies .

进程还有父进程，在大多数情况下就是启动它的进程的PID。

A process also has a parent , which in most cases is the PID of the process that launched it .

让每一个进程在屏幕上显示一个字符：父进程显示字符a，两个子进程分别显示字符b和子符c。

So that each process is displayed on the screen of a Characters : parent display characters a , respectively , two sub-processes and sub-character display character bc .

init进程是Linux的第一个进程，它是所有其他进程的父进程。

The init process is Linux 's first process , parent to all the other processes .

Init是将要在您的Linux操作系统上运行的所有其它进程的父进程。

Init is the parent of all other processes that will run on your Linux OS .

exit（）函数会令程序正常终止，并将&0377状态值返回给父进程。

The exit () function causes normal program termination and the value of status & 0377 is returned to the parent .

该进程是AIX上运行的所有其他进程的父进程或根进程。

This process is the parent , or root , process to all other processes running on AIX .

尽管父进程可以访问其子进程的进程ID并向它传递参数，但是反过来不行。

Although a parent process can access the process ID of its child process and can thus pass arguments to it , the reverse is false .

它必须与fork（）命令一起使用，所以父进程和子进程都在运行：pidtfork（void）。

This must be used along with the fork () command so both the parent and child processes are running : pid_t fork ( void ) .

执行fork之后，父进程和子进程获得打开的所有文件描述符和数据值的拷贝，所以指针对于它们都是有效的。

After the fork , the parent and child have copies of all open file descriptors and data values , so the pointer works for both .

对所打印的PID进行比较，可以看到原始进程是父进程（PID767），并且子进程（PID768）知道其父进程是谁。

Comparing the PIDs printed , you can see that the original process is the parent process ( PID 767 ), and the child process ( PID 768 ) knows who its parent is .

第一列列出用于运行该进程的用户身份，第二列列出进程的ID，第三列列出该进程的父进程ID。

The first lists the user the process is running as , the second lists the ID of the process , and the third lists the ID of the parent of the process .

考虑到fork的返回值，现在该代码可以检查确定它是父进程还是子进程，并进行相应的操作。

With the return value of fork in mind , the code can now check to see if it is the parent or child process and act accordingly .

如果您不指定任何PID，那么另一个比较有用的选项是&forest，它以树结构的形式显示命令，以及每个进程对应的父进程。

If you do not specify any PIDs , then another useful option is the & forest option , which displays the commands in a tree hierarchy , showing which process has which other process as a parent .

清单3在每个步骤打印出PID，并且该代码检查从fork返回的值来确定哪个进程是父进程，哪个进程是子进程。

In Listing 3 , the PIDs are printed out at each step , and the code checks the return value from fork to determine which process is the parent and which is the child .

现在，向父进程发送一个SIGTERM。

Let 's now send a SIGTERM to the parent process .

可以看到，PPID在父进程终止后更改为1。

You can see that the PPID changes to1 as the parent dies .

fork（）会创建一个子进程，与父进程相比只是PID和PPID不同；实际上，资源利用设为0。

Fork () creates a child process that differs from the parent process only in its PID and PPID ; in fact , the resource utilizations are set to0 .

在进程执行fork时，操作系统将创建具有新进程ID的新的子进程，复制父进程的状态（内存、环境变量等）。

When a process forks , the operating system creates a new child process with a new process ID , duplicating the state of the parent process ( memory , environment variables , and more ) .

请注意子进程如何通过getppid来知道其父进程以及父进程如何使用fork来定位其子进程。

Note how the child knows its parent through getppid and how the parent uses the result of fork to locate its child .

然后使用值18（SIGCHLD）来调用信号处理程序，确认子进程的退出，并且父进程返回到sleep（60）。

The signal handler is called with a value of 18 ( SIGCHLD ), the child 's exit is acknowledged , and the parent goes back to its sleep ( 60 ) .

PID2934是父进程，PID2935是派生（fork）并立即终止的进程。

PID2934 is the parent process , and PID2935 is the one that is forked off and terminated immediately .

bInheritHandles确定了子进程是否要继承父进程的句柄。

BInheritHandles determines whether the handles have to be inherited to the child from the parent .

记住，每个进程都有父进程，并且您可以跟踪从每个子进程一直到PID1（或称为init）的整个进程家族树。

Recall that each process has a parent , and you can trace this family tree of sorts all the way back to PID1 , otherwise known as init .

运行在一个处理器上的父进程根据numproc2的值来切换numproc1的值（并且根据由另一个处理器修改的该变量的值进行转移）。

The parent process running on one processor toggles the value of num_proc1 based on the value of num_proc2 ( and branches based on the value of the variable modified by another process ) .

核心处理这个调用的时候释放进程的全部资源并向其父进程发送SIGCHLD信号，缺省情况下这个信号是被父进程忽略的。

The kernel handles this system call by releasing the resources owned by the process and sending the parent process a SIGCHLD signal , which is ignored by default .

和非零返回值的基本原理在于，子进程始终可以通过getppid（2）调用来找出其父进程是谁，但是父进程要找出它的所有子进程却很困难。

The rationale for the0 and non-zero return values is that a child can always find out who its parent is through a call to getppid ( 2 ), but it is more difficult for a parent to find all its children .