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Remind me to implement bb_fork_exec()...
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@ -235,6 +235,12 @@ second argument to pw_encrypt(text,buffer).</p>
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<h2><a name="tips_vfork">Fork and vfork</a></h2>
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<p>Busybox hides the difference between fork() and vfork() in
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libbb/bb_fork_exec.c. If you ever want to fork and exec, use bb_fork_exec()
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(which returns a pid and takes the same arguments as execve(), although in
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this case envp can be NULL) and don't worry about it. This description is
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here in case you want to know why that does what it does.</p>
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<p>On systems that haven't got a Memory Management Unit, fork() is unreasonably
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expensive to implement, so a less capable function called vfork() is used
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instead.</p>
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@ -277,6 +283,11 @@ processes running at the same time. It means you can't have two processes
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sharing the same memory without stomping all over each other. As soon as
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the child calls exec(), the parent resumes.</p>
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<p>If the child's attempt to call exec() fails, the child should call _exit()
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rather than a normal exit(). This avoids any atexit() code that might confuse
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the parent. (The parent should never call _exit(), only a vforked child that
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failed to exec.)</p>
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<p>(Now in theory, a nommu system could just copy the _stack_ when it forks
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(which presumably is much shorter than the heap), and leave the heap shared.
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In practice, you've just wound up in a multi-threaded situation and you can't
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