fork

fork.txt

CAVEATS
     There are limits to what you can do in the child process.  To be totally
     safe you should restrict yourself to only executing async-signal safe
     operations until such time as one of the exec functions is called.  All
     APIs, including global data symbols, in any framework or library should
     be assumed to be unsafe after a fork() unless explicitly documented to be
     safe or async-signal safe.  If you need to use these frameworks in the
     child process, you must exec.  In this situation it is reasonable to exec
     yourself.