<!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
<para> 
On most UNIX systems, functions signal a <errorname>File
Not Found</errorname> error by returning
<errorcode>ENOENT</errorcode>, defined in 
<filename>errno.h</filename>.  This is usually a
<errortype>recoverable</errortype> (non-fatal) error.
</para>