+ <I>Curses</I> <I>implementations</I> <I>may</I> <I>provide</I> <I>for</I> <I>special</I> <I>handling</I> <I>of</I> <I>the</I>
+ <B>SIGINT</B><I>,</I> <B>SIGQUIT</B> <I>and</I> <B>SIGTSTP</B> <I>signals</I> <I>if</I> <I>their</I> <I>disposition</I> <I>is</I>
+ <B>SIG_DFL</B> <I>at</I> <I>the</I> <I>time</I> <B>initscr</B> <I>is</I> <I>called</I> <B>...</B>
+
+ <I>Any</I> <I>special</I> <I>handling</I> <I>for</I> <I>these</I> <I>signals</I> <I>may</I> <I>remain</I> <I>in</I> <I>effect</I> <I>for</I>
+ <I>the</I> <I>life</I> <I>of</I> <I>the</I> <I>process</I> <I>or</I> <I>until</I> <I>the</I> <I>process</I> <I>changes</I> <I>the</I> <I>disposi-</I>
+ <I>tion</I> <I>of</I> <I>the</I> <I>signal.</I>
+
+ <I>None</I> <I>of</I> <I>the</I> <I>Curses</I> <I>functions</I> <I>are</I> <I>required</I> <I>to</I> <I>be</I> <I>safe</I> <I>with</I> <I>respect</I>
+ <I>to</I> <I>signals</I> ...
+
+ This implementation establishes signal handlers during initialization,
+ e.g., <B>initscr</B> or <B>newterm</B>. Applications which must handle these signals
+ should set up the corresponding handlers <I>after</I> initializing the li-
+ brary:
+
+ <B>SIGINT</B>
+ The handler <I>attempts</I> to cleanup the screen on exit. Although it
+ <I>usually</I> works as expected, there are limitations:
+
+ <B>o</B> Walking the <B>SCREEN</B> list is unsafe, since all list management
+ is done without any signal blocking.
+
+ <B>o</B> On systems which have <B>REENTRANT</B> turned on, <B>set_term</B> uses func-
+ tions which could deadlock or misbehave in other ways.
+
+ <B>o</B> <B>endwin</B> calls other functions, many of which use stdio or other
+ library functions which are clearly unsafe.
+
+ <B>SIGTERM</B>
+ This uses the same handler as <B>SIGINT</B>, with the same limitations.
+ It is not mentioned in X/Open Curses, but is more suitable for
+ this purpose than <B>SIGQUIT</B> (which is used in debugging).
+
+ <B>SIGTSTP</B>
+ This handles the <I>stop</I> signal, used in job control. When resuming
+ the process, this implementation discards pending input with
+ <B>flushinput</B> (see <B><A HREF="curs_util.3X.html">curs_util(3X)</A></B>), and repaints the screen assuming
+ that it has been completely altered. It also updates the saved
+ terminal modes with <B>def_shell_mode</B> (see <B><A HREF="curs_kernel.3X.html">curs_kernel(3X)</A></B>).
+
+ <B>SIGWINCH</B>
+ This handles the window-size changes which were ignored in the
+ standardization efforts. The handler sets a (signal-safe) vari-
+ able which is later tested in <B>wgetch</B> (see <B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B>). If
+ <B>keypad</B> has been enabled for the corresponding window, <B>wgetch</B> re-
+ turns the key symbol <B>KEY_RESIZE</B>. At the same time, <B>wgetch</B> calls
+ <B>resizeterm</B> to adjust the standard screen <B>stdscr</B>, and update other
+ data such as <B>LINES</B> and <B>COLS</B>.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_kernel.3X.html">curs_kernel(3X)</A></B>, <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>, <B><A HREF="curs_slk.3X.html">curs_slk(3X)</A></B>, <B>curs_ter-</B>
+ <B><A HREF="curs_terminfo.3X.html">minfo(3X)</A></B>, <B><A HREF="curs_util.3X.html">curs_util(3X)</A></B>, <B><A HREF="curs_variables.3X.html">curs_variables(3X)</A></B>.
+
+
+
+ <B><A HREF="curs_initscr.3X.html">curs_initscr(3X)</A></B>