+ <B>o</B> Then it asks for the screen size via operating system calls. If
+ successful, it overrides the values from the terminal database.
+
+ <B>o</B> Finally (unless <B>use_env</B> was called with <B>FALSE</B> parameter), <B>ncurses</B>
+ examines the <B>LINES</B> or <B>COLUMNS</B> environment variables, using a value
+ in those to override the results from the operating system or ter-
+ minal database.
+
+ <B>Ncurses</B> also updates the screen size in response to <B>SIGWINCH</B>, un-
+ less overridden by the <B>LINES</B> or <B>COLUMNS</B> environment variables,
+
+
+</PRE><H3><a name="h3-use_tioctl">use_tioctl</a></H3><PRE>
+ The <B>use_tioctl</B> routine, if used, should be called before <B>initscr</B> or
+ <B>newterm</B> are called (because those compute the screen size). After
+ <B>use_tioctl</B> is called with <B>TRUE</B> as an argument, <B>ncurses</B> modifies the
+ last step in its computation of screen size as follows:
+
+ <B>o</B> checks if the <B>LINES</B> and <B>COLUMNS</B> environment variables are set to a
+ number greater than zero.
+
+ <B>o</B> for each, <B>ncurses</B> updates the corresponding environment variable
+ with the value that it has obtained via operating system call or
+ from the terminal database.
+
+ <B>o</B> <B>ncurses</B> re-fetches the value of the environment variables so that
+ it is still the environment variables which set the screen size.
+
+ The <B>use_env</B> and <B>use_tioctl</B> routines combine as summarized here:
+
+ <I>use</I><B>_</B><I>env</I> <I>use</I><B>_</B><I>tioctl</I> <I>Summary</I>
+ ----------------------------------------------------------------
+ TRUE FALSE This is the default behavior. <B>ncurses</B>
+ uses operating system calls unless over-
+ ridden by $LINES or $COLUMNS environment
+ variables.
+
+ TRUE TRUE <B>ncurses</B> updates $LINES and $COLUMNS
+ based on operating system calls.
+ FALSE TRUE <B>ncurses</B> ignores $LINES and $COLUMNS, us-
+ es operating system calls to obtain
+ size.
+ FALSE FALSE <B>ncurses</B> relies on the terminal database
+ to determine size.
+
+
+</PRE><H3><a name="h3-putwin_getwin">putwin/getwin</a></H3><PRE>
+ The <B>putwin</B> routine writes all data associated with window (or pad) <I>win</I>
+ into the file to which <I>filep</I> points. This information can be later re-
+ trieved using the <B>getwin</B> function.
+
+ The <B>getwin</B> routine reads window related data stored in the file by
+ <B>putwin</B>. The routine then creates and initializes a new window using
+ that data. It returns a pointer to the new window. There are a few
+ caveats:
+
+ <B>o</B> the data written is a copy of the <B>WINDOW</B> structure, and its associ-
+ ated character cells. The format differs between the wide-charac-
+ ter (<B>ncursesw</B>) and non-wide (<B>ncurses</B>) libraries. You can transfer
+ data between the two, however.
+
+ <B>o</B> the retrieved window is always created as a top-level window (or
+ pad), rather than a subwindow.
+
+ <B>o</B> the window's character cells contain the color pair <I>value</I>, but not
+ the actual color <I>numbers</I>. If cells in the retrieved window use
+ color pairs which have not been created in the application using
+ <B>init_pair</B>, they will not be colored when the window is refreshed.
+
+
+</PRE><H3><a name="h3-delay_output">delay_output</a></H3><PRE>
+ The <B>delay_output</B> routine inserts an <I>ms</I> millisecond pause in output.
+ This routine should not be used extensively because padding characters
+ are used rather than a CPU pause. If no padding character is speci-
+ fied, this uses <B>napms</B> to perform the delay.
+
+
+</PRE><H3><a name="h3-flushinp">flushinp</a></H3><PRE>
+ The <B>flushinp</B> routine throws away any typeahead that has been typed by
+ the user and has not yet been read by the program.
+
+
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ Except for <B>flushinp</B>, routines that return an integer return <B>ERR</B> upon
+ failure and <B>OK</B> (SVr4 specifies only "an integer value other than <B>ERR</B>")
+ upon successful completion.
+
+ Routines that return pointers return <B>NULL</B> on error.