+The four functions with \fIn\fP as the last argument return
+a leading substring at most \fIn\fP characters long
+(exclusive of the trailing zeroed \fBcchar_t\fR.
+Transfer stops at the end of the current line, or when \fIn\fP characters have
+been stored at the location referenced by \fIwchstr\fP.
+.PP
+Constants defined in \fB<curses.h>\fP can be used with the \fB&\fP (logical
+AND) operator to extract the character or the attribute alone from any position
+in the \fIwchstr\fP [see \fBgetcchar\fP(3X)].
+.SH RETURN VALUE
+Upon successful completion, these functions return
+\fBOK\fP.
+Otherwise, they return
+\fBERR\fP.
+.PP
+X/Open Curses defines no error conditions.
+This implementation returns an error
+.bP
+if the \fIwin\fP parameter is null or
+.bP
+if the \fIwchstr\fP parameter is null.
+.PP
+Functions with a \*(``mv\*('' prefix first perform a cursor movement using
+\fBwmove\fP, and return an error if the position is outside the window,
+or if the window pointer is null.