-</PRE><H3><a name="h3-filter_nofilter">filter/nofilter</a></H3><PRE>
- The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG>
+ <STRONG>o</STRONG> Values above 256 may be the codes for function keys. The function
+ key name is displayed.
+
+ <STRONG>o</STRONG> Otherwise (if there is no corresponding name and the key is not a
+ character) the function returns null, to denote an error. X/Open
+ also lists an "UNKNOWN KEY" return value, which some
+ implementations return rather than null.
+
+ The corresponding <STRONG>key_name</STRONG> returns a multibyte character string
+ corresponding to the wide-character value <EM>w</EM>. The two functions
+ (<STRONG>keyname</STRONG> and <STRONG>key_name</STRONG>) do not return the same set of strings:
+
+ <STRONG>o</STRONG> <STRONG>keyname</STRONG> returns null where <STRONG>key_name</STRONG> would display a meta character.
+
+ <STRONG>o</STRONG> <STRONG>key_name</STRONG> does not return the name of a function key.
+
+
+</PRE><H3><a name="h3-filter_nofilter">filter, nofilter</a></H3><PRE>
+ The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG>