ncurses-programming-howto.html

ncurses 库 可能有用酒用 没用就算了 我觉得还可以用

    then use htmldoc to get pdf file with
        htmldoc --size universal -t pdf --firstpage p1 -f <output file name.pdf>
        NCURSES-ONE-BIG-FILE.html
    for ps, you would use
        htmldoc --size universal -t ps --firstpage p1 -f <output file name.ps>
        NCURSES-ONE-BIG-FILE.html</font>
</pre></td>
</tr>
</table>
<p>See <a href="http://www.tldp.org/LDP/LDP-Author-Guide/" target=
"_top">LDP Author guide</a> for more details. If all else failes,
mail me at <a href="[e-mail]" target=
"_top">[e-mail]</a></p>
</div>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="CREDITS" id="CREDITS">1.7.
Credits</a></h3>
<p>I thank <a href="mailto:[e-mail]" target=
"_top">Sharath</a> and Emre Akbas for helping me with few sections.
The introduction was initially written by sharath. I rewrote it
with few excerpts taken from his initial work. Emre helped in
writing printw and scanw sections.</p>
<p>Perl equivalents of the example programs are contributed by
<a href="mailto:[e-mail]" target="_top">Anuradha
Ratnaweera</a>.</p>
<p>Then comes <a href="mailto:[e-mail]" target=
"_top">Ravi Parimi</a>, my dearest friend, who has been on this
project before even one line was written. He constantly bombarded
me with suggestions and patiently reviewed the whole text. He also
checked each program on Linux and Solaris.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="WISHLIST" id="WISHLIST">1.8. Wish
List</a></h3>
<p>This is the wish list, in the order of priority. If you have a
wish or you want to work on completing the wish, mail <a href=
"mailto:[e-mail]" target="_top">me</a>.</p>
<ul>
<li>
<p>Add examples to last parts of forms section.</p>
</li>
<li>
<p>Prepare a Demo showing all the programs and allow the user to
browse through description of each program. Let the user compile
and see the program in action. A dialog based interface is
preferred.</p>
</li>
<li>
<p>Add debug info. _tracef, _tracemouse stuff.</p>
</li>
<li>
<p>Accessing termcap, terminfo using functions provided by ncurses
package.</p>
</li>
<li>
<p>Working on two terminals simultaneously.</p>
</li>
<li>
<p>Add more stuff to miscellaneous section.</p>
</li>
</ul>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="COPYRIGHT" id="COPYRIGHT">1.9.
Copyright</a></h3>
<p>Copyright &copy; 2001 by Pradeep Padala.</p>
<p>Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, distribute with modifications,
sublicense, and/or sell copies of the Software, and to permit
persons to whom the Software is furnished to do so, subject to the
following conditions:</p>
<p>The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.</p>
<p>THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.</p>
<p>Except as contained in this notice, the name(s) of the above
copyright holders shall not be used in advertising or otherwise to
promote the sale, use or other dealings in this Software without
prior written authorization.</p>
</div>
</div>
<div class="SECT1">
<hr>
<h2 class="SECT1"><a name="HELLOWORLD" id="HELLOWORLD">2. Hello
World !!!</a></h2>
<p>Welcome to the world of curses. Before we plunge into the
library and look into its various features, let's write a simple
program and say hello to the world.</p>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="COMPILECURSES" id="COMPILECURSES">2.1.
Compiling With the NCURSES Library</a></h3>
<p>To use ncurses library functions, you have to include ncurses.h
in your programs. To link the program with ncurses the flag
-lncurses should be added.</p>
<table border="0" bgcolor="#E0E0E0" width="100%">
<tr>
<td>
<pre class="PROGRAMLISTING">
<font color="#000000">    #include &lt;ncurses.h&gt;
    .
    .
    .

    compile and link: gcc &lt;program file&gt; -lncurses</font>
</pre></td>
</tr>
</table>
<div class="EXAMPLE"><a name="BHW" id="BHW"></a>
<p><b>Example 1. The Hello World !!! Program</b></p>
<table border="0" bgcolor="#E0E0E0" width="100%">
<tr>
<td>
<pre class="PROGRAMLISTING">
<font color="#000000"><span class=
"INLINEMEDIAOBJECT">#include &lt;ncurses.h&gt;

int main()
{       
        initscr();                      /* Start curses mode              */
        printw("Hello World !!!");      /* Print Hello World              */
        refresh();                      /* Print it on to the real screen */
        getch();                        /* Wait for user input */
        endwin();                       /* End curses mode                */

        return 0;
}</span></font>
</pre></td>
</tr>
</table>
</div>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="DISSECTION" id="DISSECTION">2.2.
Dissection</a></h3>
<p>The above program prints "Hello World !!!" to the screen and
exits. This program shows how to initialize curses and do screen
manipulation and end curses mode. Let's dissect it line by
line.</p>
<div class="SECT3">
<hr>
<h4 class="SECT3"><a name="ABOUT-INITSCR" id="ABOUT-INITSCR">2.2.1.
About initscr()</a></h4>
<p>The function initscr() initializes the terminal in curses mode.
In some implementations, it clears the screen and presents a blank
screen. To do any screen manipulation using curses package this has
to be called first. This function initializes the curses system and
allocates memory for our present window (called <var class=
"LITERAL">stdscr</var>) and some other data-structures. Under
extreme cases this function might fail due to insufficient memory
to allocate memory for curses library's data structures.</p>
<p>After this is done, we can do a variety of initializations to
customize our curses settings. These details will be explained
<a href="#INIT">later</a> .</p>
</div>
<div class="SECT3">
<hr>
<h4 class="SECT3"><a name="MYST-REFRESH" id="MYST-REFRESH">2.2.2.
The mysterious refresh()</a></h4>
<p>The next line printw prints the string "Hello World !!!" on to
the screen. This function is analogous to normal printf in all
respects except that it prints the data on a window called stdscr
at the current (y,x) co-ordinates. Since our present co-ordinates
are at 0,0 the string is printed at the left hand corner of the
window.</p>
<p>This brings us to that mysterious refresh(). Well, when we
called printw the data is actually written to an imaginary window,
which is not updated on the screen yet. The job of printw is to
update a few flags and data structures and write the data to a
buffer corresponding to stdscr. In order to show it on the screen,
we need to call refresh() and tell the curses system to dump the
contents on the screen.</p>
<p>The philosophy behind all this is to allow the programmer to do
multiple updates on the imaginary screen or windows and do a
refresh once all his screen update is done. refresh() checks the
window and updates only the portion which has been changed. This
improves performance and offers greater flexibility too. But, it is
sometimes frustrating to beginners. A common mistake committed by
beginners is to forget to call refresh() after they did some update
through printw() class of functions. I still forget to add it
sometimes :-)</p>
</div>
<div class="SECT3">
<hr>
<h4 class="SECT3"><a name="ABOUT-ENDWIN" id="ABOUT-ENDWIN">2.2.3.
About endwin()</a></h4>
<p>And finally don't forget to end the curses mode. Otherwise your
terminal might behave strangely after the program quits. endwin()
frees the memory taken by curses sub-system and its data structures
and puts the terminal in normal mode. This function must be called
after you are done with the curses mode.</p>
</div>
</div>
</div>
<div class="SECT1">
<hr>
<h2 class="SECT1"><a name="GORY" id="GORY">3. The Gory
Details</a></h2>
<p>Now that we have seen how to write a simple curses program let's
get into the details. There are many functions that help customize
what you see on screen and many features which can be put to full
use.</p>
<p>Here we go...</p>
</div>
<div class="SECT1">
<hr>
<h2 class="SECT1"><a name="INIT" id="INIT">4.
Initialization</a></h2>
<p>We now know that to initialize curses system the function
initscr() has to be called. There are functions which can be called
after this initialization to customize our curses session. We may
ask the curses system to set the terminal in raw mode or initialize
color or initialize the mouse etc.. Let's discuss some of the
functions that are normally called immediately after initscr();</p>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="ABOUTINIT" id="ABOUTINIT">4.1.
Initialization functions</a></h3>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="RAWCBREAK" id="RAWCBREAK">4.2. raw() and
cbreak()</a></h3>
<p>Normally the terminal driver buffers the characters a user types
until a new line or carriage return is encountered. But most
programs require that the characters be available as soon as the
user types them. The above two functions are used to disable line
buffering. The difference between these two functions is in the way
control characters like suspend (CTRL-Z), interrupt and quit
(CTRL-C) are passed to the program. In the raw() mode these
characters are directly passed to the program without generating a
signal. In the <var class="LITERAL">cbreak()</var> mode these
control characters are interpreted as any other character by the
terminal driver. I personally prefer to use raw() as I can exercise
greater control over what the user does.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="ECHONOECHO" id="ECHONOECHO">4.3. echo()
and noecho()</a></h3>
<p>These functions control the echoing of characters typed by the
user to the terminal. <var class="LITERAL">noecho()</var> switches
off echoing. The reason you might want to do this is to gain more
control over echoing or to suppress unnecessary echoing while
taking input from the user through the getch() etc. functions. Most
of the interactive programs call <var class=
"LITERAL">noecho()</var> at initialization and do the echoing of
characters in a controlled manner. It gives the programmer the
flexibility of echoing characters at any place in the window
without updating current (y,x) co-ordinates.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="KEYPAD" id="KEYPAD">4.4.
keypad()</a></h3>
<p>This is my favorite initialization function. It enables the
reading of function keys like F1, F2, arrow keys etc. Almost every
interactive program enables this, as arrow keys are a major part of
any User Interface. Do <var class="LITERAL">keypad(stdscr,
TRUE)</var> to enable this feature for the regular screen (stdscr).
You will learn more about key management in later sections of this
document.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="HALFDELAY" id="HALFDELAY">4.5.
halfdelay()</a></h3>
<p>This function, though not used very often, is a useful one at
times. halfdelay()is called to enable the half-delay mode, which is
similar to the cbreak() mode in that characters typed are
immediately available to program. However, it waits for 'X' tenths
of a second for input and then returns ERR, if no input is
available. 'X' is the timeout value passed to the function
halfdelay(). This function is useful when you want to ask the user
for input, and if he doesn't respond with in certain time, we can
do some thing else. One possible example is a timeout at the
password prompt.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="MISCINIT" id="MISCINIT">4.6.
Miscellaneous Initialization functions</a></h3>
<p>There are few more functions which are called at initialization
to customize curses behavior. They are not used as extensively as
those mentioned above. Some of them are explained where
appropriate.</p>
</div>
<div class="SECT2">
<hr>
<h3 class="SECT2"><a name="INITEX" id="INITEX">4.7. An
Example</a></h3>
<p>Let's write a program which will clarify the usage of these
functions.</p>
<div class="EXAMPLE"><a name="BINFU" id="BINFU"></a>
<p><b>Example 2. Initialization Function Usage example</b></p>
<table border="0" bgcolor="#E0E0E0" width="100%">
<tr>
<td>
<pre class="PROGRAMLISTING">
<font color="#000000"><span class=
"INLINEMEDIAOBJECT">#include &lt;ncurses.h&gt;

int main()
{       int ch;

        initscr();                      /* Start curses mode            */
        raw();                          /* Line buffering disabled      */
        keypad(stdscr, TRUE);           /* We get F1, F2 etc..          */
        noecho();                       /* Don't echo() while we do getch */

        printw("Type any character to see it in bold\n");
        ch = getch();                   /* If raw() hadn't been called
                                         * we have to press enter before it
                                         * gets to the program          */
        if(ch == KEY_F(1))              /* Without keypad enabled this will */
                printw("F1 Key pressed");/*  not get to us either       */
                                        /* Without noecho() some ugly escape
                                         * charachters might have been printed
                                         * on screen                    */
        else
        {       printw("The pressed key is ");
                attron(A_BOLD);
                printw("%c", ch);
                attroff(A_BOLD);