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+<H1 class="no-header">curs_initscr 3X</H1>
<PRE>
-<!-- Manpage converted by man2html 3.0.1 -->
+<B><A HREF="curs_initscr.3X.html">curs_initscr(3X)</A></B> <B><A HREF="curs_initscr.3X.html">curs_initscr(3X)</A></B>
-</PRE>
-<H2>NAME</H2><PRE>
- <B>initscr</B>, <B>newterm</B>, <B>endwin</B>, <B>isendwin</B>, <B>set_term</B>, <B>delscreen</B> -
- <B>curses</B> screen initialization and manipulation routines
-</PRE>
-<H2>SYNOPSIS</H2><PRE>
+
+</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
+ <B>initscr</B>, <B>newterm</B>, <B>endwin</B>, <B>isendwin</B>, <B>set_term</B>, <B>delscreen</B> - <B>curses</B> screen
+ initialization and manipulation routines
+
+
+</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<B>#include</B> <B><curses.h></B>
<B>WINDOW</B> <B>*initscr(void);</B>
<B>int</B> <B>endwin(void);</B>
+
<B>bool</B> <B>isendwin(void);</B>
- <B>SCREEN</B> <B>*newterm(const</B> <B>char</B> <B>*type,</B> <B>FILE</B> <B>*outfd,</B> <B>FILE</B>
- <B>*infd);</B>
- <B>SCREEN</B> <B>*set_term(SCREEN</B> <B>*new);</B>
- <B>void</B> <B>delscreen(SCREEN*</B> <B>sp);</B>
+ <B>SCREEN</B> <B>*newterm(const</B> <B>char</B> <B>*</B><I>type</I><B>,</B> <B>FILE</B> <B>*</B><I>outfd</I><B>,</B> <B>FILE</B> <B>*</B><I>infd</I><B>);</B>
+ <B>SCREEN</B> <B>*set_term(SCREEN</B> <B>*</B><I>new</I><B>);</B>
+ <B>void</B> <B>delscreen(SCREEN*</B> <I>sp</I><B>);</B>
-</PRE>
-<H2>DESCRIPTION</H2><PRE>
- <B>initscr</B> is normally the first <B>curses</B> routine to call when
- initializing a program. A few special routines sometimes
- need to be called before it; these are <B>slk_init</B>, <B>filter</B>,
- <B>ripoffline</B>, <B>use_env</B>. For multiple-terminal applications,
- <B>newterm</B> may be called before <B>initscr</B>.
-
- The initscr code determines the terminal type and initial-
- izes all <B>curses</B> data structures. <B>initscr</B> also causes the
- first call to <B>refresh</B> to clear the screen. If errors
- occur, <B>initscr</B> writes an appropriate error message to
- standard error and exits; otherwise, a pointer is returned
- to <B>stdscr</B>.
-
- A program that outputs to more than one terminal should
- use the <B>newterm</B> routine for each terminal instead of
- <B>initscr</B>. A program that needs to inspect capabilities, so
- it can continue to run in a line-oriented mode if the ter-
- minal cannot support a screen-oriented program, would also
- use <B>newterm</B>. The routine <B>newterm</B> should be called once
- for each terminal. It returns a variable of type <B>SCREEN</B> <B>*</B>
- which should be saved as a reference to that terminal.
- The arguments are the <I>type</I> of the terminal to be used in
- place of <B>$TERM</B>, a file pointer for output to the terminal,
- and another file pointer for input from the terminal (if
- <I>type</I> is <B>NULL</B>, <B>$TERM</B> will be used). The program must also
- call <B>endwin</B> for each terminal being used before exiting
- from <B>curses</B>. If <B>newterm</B> is called more than once for the
- same terminal, the first terminal referred to must be the
- last one for which <B>endwin</B> is called.
-
- A program should always call <B>endwin</B> before exiting or
- escaping from <B>curses</B> mode temporarily. This routine
- restores tty modes, moves the cursor to the lower left-
- hand corner of the screen and resets the terminal into the
- proper non-visual mode. Calling <B>refresh</B> or <B>doupdate</B> after
- a temporary escape causes the program to resume visual
- mode.
-
- The <B>isendwin</B> routine returns <B>TRUE</B> if <B>endwin</B> has been
- called without any subsequent calls to <B>wrefresh</B>, and <B>FALSE</B>
- otherwise.
-
- The <B>set_term</B> routine is used to switch between different
- terminals. The screen reference <B>new</B> becomes the new cur-
- rent terminal. The previous terminal is returned by the
- routine. This is the only routine which manipulates
- <B>SCREEN</B> pointers; all other routines affect only the cur-
- rent terminal.
-
- The <B>delscreen</B> routine frees storage associated with the
- <B>SCREEN</B> data structure. The <B>endwin</B> routine does not do
- this, so <B>delscreen</B> should be called after <B>endwin</B> if a par-
- ticular <B>SCREEN</B> is no longer needed.
+</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
-</PRE>
-<H2>RETURN VALUE</H2><PRE>
- <B>endwin</B> returns the integer <B>ERR</B> upon failure and <B>OK</B> upon
- successful completion.
+</PRE><H3><a name="h3-initscr">initscr</a></H3><PRE>
+ <B>initscr</B> is normally the first <B>curses</B> routine to call when initializing
+ a program. A few special routines sometimes need to be called before
+ it; these are <B><A HREF="curs_slk.3X.html">slk_init(3X)</A></B>, <B>filter</B>, <B>ripoffline</B>, <B>use_env</B>. For multiple-
+ terminal applications, <B>newterm</B> may be called before <B>initscr</B>.
+
+ The initscr code determines the terminal type and initializes all <B>curs-</B>
+ <B>es</B> data structures. <B>initscr</B> also causes the first call to <B><A HREF="curscurs_refresh.3X.html">refresh(3X)</A></B>
+ to clear the screen. If errors occur, <B>initscr</B> writes an appropriate
+ error message to standard error and exits; otherwise, a pointer is re-
+ turned to <B>stdscr</B>.
+
+
+</PRE><H3><a name="h3-newterm">newterm</a></H3><PRE>
+ A program that outputs to more than one terminal should use the <B>newterm</B>
+ routine for each terminal instead of <B>initscr</B>. A program that needs to
+ inspect capabilities, so it can continue to run in a line-oriented mode
+ if the terminal cannot support a screen-oriented program, would also
+ use <B>newterm</B>. The routine <B>newterm</B> should be called once for each termi-
+ nal. It returns a variable of type <B>SCREEN</B> <B>*</B> which should be saved as a
+ reference to that terminal. <B>newterm</B>'s arguments are
+
+ <B>o</B> the <I>type</I> of the terminal to be used in place of <B>$TERM</B>,
+
+ <B>o</B> a file pointer for output to the terminal, and
+
+ <B>o</B> another file pointer for input from the terminal
+
+ If the <I>type</I> parameter is <B>NULL</B>, <B>$TERM</B> will be used.
+
+
+</PRE><H3><a name="h3-endwin">endwin</a></H3><PRE>
+ The program must also call <B>endwin</B> for each terminal being used before
+ exiting from <B>curses</B>. If <B>newterm</B> is called more than once for the same
+ terminal, the first terminal referred to must be the last one for which
+ <B>endwin</B> is called.
+
+ A program should always call <B>endwin</B> before exiting or escaping from
+ <B>curses</B> mode temporarily. This routine
+
+ <B>o</B> resets colors to correspond with the default color pair 0,
+
+ <B>o</B> moves the cursor to the lower left-hand corner of the screen,
+
+ <B>o</B> clears the remainder of the line so that it uses the default col-
+ ors,
+
+ <B>o</B> sets the cursor to normal visibility (see <B><A HREF="curs_kernel.3X.html">curs_set(3X)</A></B>),
+
+ <B>o</B> stops cursor-addressing mode using the <I>exit</I><B>_</B><I>ca</I><B>_</B><I>mode</I> terminal capa-
+ bility,
+
+ <B>o</B> restores tty modes (see <B><A HREF="curs_kernel.3X.html">reset_shell_mode(3X)</A></B>).
+
+ Calling <B><A HREF="curs_refresh.3X.html">refresh(3X)</A></B> or <B><A HREF="curs_refresh.3X.html">doupdate(3X)</A></B> after a temporary escape causes the
+ program to resume visual mode.
+
+
+</PRE><H3><a name="h3-isendwin">isendwin</a></H3><PRE>
+ The <B>isendwin</B> routine returns <B>TRUE</B> if <B>endwin</B> has been called without any
+ subsequent calls to <B>wrefresh</B>, and <B>FALSE</B> otherwise.
+
+
+</PRE><H3><a name="h3-set_term">set_term</a></H3><PRE>
+ The <B>set_term</B> routine is used to switch between different terminals.
+ The screen reference <B>new</B> becomes the new current terminal. The previ-
+ ous terminal is returned by the routine. This is the only routine
+ which manipulates <B>SCREEN</B> pointers; all other routines affect only the
+ current terminal.
+
+
+</PRE><H3><a name="h3-delscreen">delscreen</a></H3><PRE>
+ The <B>delscreen</B> routine frees storage associated with the <B>SCREEN</B> data
+ structure. The <B>endwin</B> routine does not do this, so <B>delscreen</B> should be
+ called after <B>endwin</B> if a particular <B>SCREEN</B> is no longer needed.
+
+
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ <B>endwin</B> returns the integer <B>ERR</B> upon failure and <B>OK</B> upon successful com-
+ pletion.
Routines that return pointers always return <B>NULL</B> on error.
+ X/Open defines no error conditions. In this implementation
-</PRE>
-<H2>NOTES</H2><PRE>
- Note that <B>initscr</B> and <B>newterm</B> may be macros.
+ <B>o</B> <B>endwin</B> returns an error if the terminal was not initialized.
+ <B>o</B> <B>newterm</B> returns an error if it cannot allocate the data structures
+ for the screen, or for the top-level windows within the screen,
+ i.e., <B>curscr</B>, <B>newscr</B>, or <B>stdscr</B>.
-</PRE>
-<H2>PORTABILITY</H2><PRE>
- These functions are described in the XSI Curses standard,
- Issue 4. It specifies that portable applications must not
- call <B>initscr</B> more than once.
+ <B>o</B> <B>set_term</B> returns no error.
- Old versions of curses, e.g., BSD 4.4, may have returned a
- null pointer from <B>initscr</B> when an error is detected,
- rather than exiting. It is safe but redundant to check
- the return value of <B>initscr</B> in XSI Curses.
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ These functions were described in the XSI Curses standard, Issue 4. As
+ of 2015, the current document is X/Open Curses, Issue 7.
-</PRE>
-<H2>SEE ALSO</H2><PRE>
- <B><A HREF="ncurses.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><A HREF="curs_util.3x.html">curs_util(3x)</A></B>
+</PRE><H3><a name="h3-Differences">Differences</a></H3><PRE>
+ X/Open specifies that portable applications must not call <B>initscr</B> more
+ than once:
+
+ <B>o</B> The portable way to use <B>initscr</B> is once only, using <B>refresh</B> (see
+ <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>) to restore the screen after <B>endwin</B>.
+
+ <B>o</B> This implementation allows using <B>initscr</B> after <B>endwin</B>.
+
+ Old versions of curses, e.g., BSD 4.4, may have returned a null pointer
+ from <B>initscr</B> when an error is detected, rather than exiting. It is
+ safe but redundant to check the return value of <B>initscr</B> in XSI Curses.
+
+
+</PRE><H3><a name="h3-Unset-TERM-Variable">Unset TERM Variable</a></H3><PRE>
+ If the TERM variable is missing or empty, <B>initscr</B> uses the value "un-
+ known", which normally corresponds to a terminal entry with the <I>generic</I>
+ (<I>gn</I>) capability. Generic entries are detected by <B>setupterm</B> (see
+ <B><A HREF="curs_terminfo.3X.html">curs_terminfo(3X)</A></B>) and cannot be used for full-screen operation. Other
+ implementations may handle a missing/empty TERM variable differently.
+
+
+</PRE><H3><a name="h3-Signal-Handlers">Signal Handlers</a></H3><PRE>
+ Quoting from X/Open Curses, section 3.1.1:
+
+ <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>
</PRE>
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-<ADDRESS>
-Man(1) output converted with
-<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
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+<div class="nav">
+<ul>
+<li><a href="#h2-NAME">NAME</a></li>
+<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
+<ul>
+<li><a href="#h3-initscr">initscr</a></li>
+<li><a href="#h3-newterm">newterm</a></li>
+<li><a href="#h3-endwin">endwin</a></li>
+<li><a href="#h3-isendwin">isendwin</a></li>
+<li><a href="#h3-set_term">set_term</a></li>
+<li><a href="#h3-delscreen">delscreen</a></li>
+</ul>
+</li>
+<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
+<li><a href="#h2-PORTABILITY">PORTABILITY</a>
+<ul>
+<li><a href="#h3-Differences">Differences</a></li>
+<li><a href="#h3-Unset-TERM-Variable">Unset TERM Variable</a></li>
+<li><a href="#h3-Signal-Handlers">Signal Handlers</a></li>
+</ul>
+</li>
+<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
+</ul>
+</div>
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