Somewhat more generally, fileno returns the operating system's file descriptor number for the open file. Perl will sometimes let you pretend something is a file which really isn't, as in imp's example. In that case, Perl will give you a filehandle that isn't connected to a real file. If you create such a filehandle then ask for the operating system's descriptor, there isn't really an open file, so undef is returned.

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sgifford's Web page

In reply to Re: perldoc -f fileno by sgifford
in thread perldoc -f fileno by Tommy

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