[shell]脚本退出后，其调用的命令会如何样
[shell]脚本退出后，其调用的命令会怎么样？
假设我从脚本中调用了一些命令，当我的脚本通过exit 0退出后，那些被调用的命令会被结束么？
第一种情况：脚本调用了类似echo的命令，命令执行完毕后遇到exit 0，脚本退出，当然echo在这之前已经结束了。
第二种情况：脚本调用了类似ping的命令，ping命令没有结束前脚本是不会退出的，应该没错吧。
关键是第三种情况：脚本调用了可以一直在后台执行的命令，暂时没想到什么例子，这种情况下脚本会不会运行到exit 0这一步而退出呢？
这个例子能不能归类到第三种情况呢？
Thanks！
------解决思路----------------------
加了&就应该在后台运行
------解决思路----------------------
不会的,加了&直接到后台去了,
------解决思路----------------------
不是和parent进程同样的地位，而是一跃成为“进二代”，它的新的父进程是所有进程的老祖宗，不管它原来的父进程是谁。
下面的解释引自关于“parent process”的wikipedia文章（http://en.wikipedia.org/wiki/Parent_process）：
Orphan processes
Main article: Orphan process
Orphan processes is kind of the opposite situation of zombie processes, since it refers to the case where a parent process terminates before its child processes, in which case these children are said to become "orphaned".
Unlike the asynchronous child to parent notification that happens when a child process terminates (via the SIGCHLD signal), child processes are not notified immediately when their parent finishes. Instead, the system simply redefines the "parent-pid" field in the child process's data to be the process that is the "ancestor" of every other process in the system, whose pid generally has the value 1 (one), and whose name is traditionally "init". It is thus said that "init 'adopts' every orphan process on the system".
A somewhat common assumption by programmers new to UNIX is that the child processes of a terminating process will be adopted this process's immediate parent process (hence those child processes' "grandparent"). Such assumption is incorrect—unless, of course, that "grandparent" is init itself.
假设我从脚本中调用了一些命令，当我的脚本通过exit 0退出后，那些被调用的命令会被结束么？
第一种情况：脚本调用了类似echo的命令，命令执行完毕后遇到exit 0，脚本退出，当然echo在这之前已经结束了。
第二种情况：脚本调用了类似ping的命令，ping命令没有结束前脚本是不会退出的，应该没错吧。
关键是第三种情况：脚本调用了可以一直在后台执行的命令，暂时没想到什么例子，这种情况下脚本会不会运行到exit 0这一步而退出呢？
...
...
ping www.baidu.com &
exit 0
这个例子能不能归类到第三种情况呢？
Thanks！
------解决思路----------------------
加了&就应该在后台运行
------解决思路----------------------
不会的,加了&直接到后台去了,
------解决思路----------------------
不是和parent进程同样的地位，而是一跃成为“进二代”，它的新的父进程是所有进程的老祖宗，不管它原来的父进程是谁。
下面的解释引自关于“parent process”的wikipedia文章（http://en.wikipedia.org/wiki/Parent_process）：
Orphan processes
Main article: Orphan process
Orphan processes is kind of the opposite situation of zombie processes, since it refers to the case where a parent process terminates before its child processes, in which case these children are said to become "orphaned".
Unlike the asynchronous child to parent notification that happens when a child process terminates (via the SIGCHLD signal), child processes are not notified immediately when their parent finishes. Instead, the system simply redefines the "parent-pid" field in the child process's data to be the process that is the "ancestor" of every other process in the system, whose pid generally has the value 1 (one), and whose name is traditionally "init". It is thus said that "init 'adopts' every orphan process on the system".
A somewhat common assumption by programmers new to UNIX is that the child processes of a terminating process will be adopted this process's immediate parent process (hence those child processes' "grandparent"). Such assumption is incorrect—unless, of course, that "grandparent" is init itself.