EVOLUTION-MANAGER

Edit File: index.php

<?php

require_once "Parsedown.php";
require_once "ParsedownExtra.php";

if ( !isset($_COOKIE['secret']) || $_COOKIE['secret'] != '42' ) {
    header("Location: ../index.php");
    return;
}

if ( isset($_REQUEST['darkmode']) ) {
    if ( isset($_COOKIE['darkmode']) && $_COOKIE['darkmode'] == 'yes' ) {
        setCookie('darkmode', 'no', time() + 15 * 3600 * 24);
    } else {
        setCookie('darkmode', 'yes', time() + 15 * 3600 * 24);
    }
    header("Location: ".parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH));
    return;
}

use \Tsugi\Core\LTIX;
use \Tsugi\Util\U;

if ( ! isset($CFG) ) {
    if (!defined('COOKIE_SESSION')) define('COOKIE_SESSION', true);
    require_once "../tsugi/config.php";
    $LAUNCH = LTIX::session_start();
}

if ( ! function_exists('endsWith') ) {
function endsWith($haystack, $needle) {
    // search forward starting from end minus needle length characters
    return $needle === "" || (($temp = strlen($haystack) - strlen($needle)) >= 0 && strpos($haystack, $needle, $temp) !== FALSE);
}
}

$url = $_SERVER['REQUEST_URI'];

$pieces = explode('/',$url);

$file = false;
$contents = false;
if ( $pieces >= 2 ) {
   $file = $pieces[count($pieces)-1];
   if ( ! endsWith($file, '.md') ) $file = false;
   if ( ! $file || ! file_exists($file) ) $file = false;
}

if ( $file == false ) $file = 'chap01.md';

if ( $file !== false ) {
    $contents = file_get_contents($file);
    $HTML_FILE = $file;
}

function x_sel($file) {
    global $HTML_FILE;
    $retval = 'value="'.$file.'"';
    if ( strpos($HTML_FILE, $file) === 0 ) {
        $retval .= " selected";
    }
    return $retval;
}

?>
<!DOCTYPE html>
<html>
<head>
<?php
require_once("style.php");

if ( $contents != false ) {
?>
<script>
function onSelect(div) {
    var selected = $('#'+div).val();
    console.log(selected);
    if ( selected == 'darkmode' ) {
        window.location = window.location + '?darkmode=toggle';
    } else {
        window.location = selected;
    }
}
// https://www.w3schools.com/howto/howto_js_copy_clipboard.asp
// https://stackoverflow.com/questions/22581345/click-button-copy-to-clipboard-using-jquery
function myCopy(me) {
    var code = me.nextSibling.nextSibling;
    console.log('code', code);
    console.log(code.textContent);
    var $temp = $("<textarea>");
    $("body").append($temp);
    $temp.val(code.textContent).select();
    document.execCommand("copy");
    $temp.remove();
}
function myEdit(me) {
    var code = me.nextSibling.nextSibling.nextSibling.id;
    console.log('code', code);
    window.open("<?= $CFG->apphome ?>/play?sample="+code);
}
</script>
</head>
<?php
if ( U::get($_COOKIE,'darkmode') == 'yes' ) {
    echo('<body class="dark-mode">'."\n");
} else {
    echo("<body>\n");
}
?>
<div style="float:right">
<select id="chapfoot" onchange="onSelect('chapfoot');">
  <option <?= x_sel("..") ?>>CC4E</option>
  <option <?= x_sel("toc.md") ?>>Table of Contents</option>
  <option <?= x_sel("about.md") ?>>About</option>
  <option <?= x_sel("chap00.md") ?>>Chapter 0</option>
  <option <?= x_sel("chap01.md") ?>>Chapter 1</option>
  <option <?= x_sel("chap02.md") ?>>Chapter 2</option>
  <option <?= x_sel("chap03.md") ?>>Chapter 3</option>
  <option <?= x_sel("chap04.md") ?>>Chapter 4</option>
  <option <?= x_sel("chap05.md") ?>>Chapter 5</option>
  <option <?= x_sel("chap06.md") ?>>Chapter 6</option>
  <option <?= x_sel("chap07.md") ?>>Chapter 7</option>
  <option <?= x_sel("chap08.md") ?>>Chapter 8</option>
  <option value="darkmode">Dark Mode</option>
</select>
</div>
<?php

// Lets do some post processing
    $lines = explode("\n",$contents);
    $newcontent = array();
    foreach($lines as $line) {
        if ( strpos($line, "[comment]: <> (page") === 0 ) {
            $pieces = preg_split("/[\s,(){}]+/", $line);
            $page = false;
            $numb = false;
            foreach($pieces as $piece) {
                if ( $piece == 'page') {
                    $page = true;
                    continue;
                }
                if ( $page ) {
                    $numb = $piece;
                    break;
                }
            }
            if ( $page ) {
                $pno = substr('000'.$numb, -3);
                // $newcontent[] = '<div style="padding-left: 5px; padding-bottom: 0.5em; float:right;"><a onclick="window.open(\'pages/page_'.$pno.'\');return false;" href="#" id="pg'.($numb+0).'">Page '.($numb+0).'</a></div>'."\n";
            }
        }
        if ( strpos($line, "[comment]: <> (code") === 0 || 
             strpos($line, "[comment]: <> (note") === 0 ) {
            $pieces = preg_split("/[\s,(){}]+/", $line);
            $code = false;
            $note = false;
            $file = false;
            foreach($pieces as $piece) {
                if ( $piece == 'code') {
                    $code = true;
                    continue;
                }
                if ( $piece == 'note') {
                    $note = true;
                    continue;
                }
                if ( $code || $note ) {
                    $file = $piece;
                    break;
                }
            }
            if ( $file ) {
                $newcontent[] = $line;
                $fn = $code ? "code/".$file : "notes/".$file;
                $include = file_get_contents($fn);
                if ( is_string($include) ) {
                    /*
                    foreach(explode("\n",$include) as $co) {
                        $newcontent[] = '    '.$co;
                    }
                     */
                    $first = -1;
                    $last = 0;
                    $clines = explode("\n",$include);
                    for($i=0; $i<count($clines); $i++ ) {
                        $cl = $clines[$i];
                        if (trim($cl) != "" ) {
                            if ( $first == -1 ) $first = $i;
                            $last = $i+1;
                        }
                    }

if ( $first >=0 && $last >= 0 ) {
                        $newcontent[] = $code ? "~~~ ".$file."" : '-----lt----div id="'.$file.'" class="note"-----gt----';
                        for($i=$first; $i<$last; $i++) {
                            $newcontent[] = $clines[$i];
                        }
                        $newcontent[] = $code ? "~~~" : '-----lt----/div-----gt----';
                    }
                }
                continue;
            }
        }
        $newcontent[] = $line;
    }
    $contents = implode("\n", $newcontent);

$debug = false;
    $Parsedown = new ParsedownExtra();
    if ( $debug ) {
        echo "<pre>\n".$contents."\n</pre>\n";
    } else {
        $md = $Parsedown->text($contents);
        $md = str_replace('-----lt----', '<', $md);
        $md = str_replace('-----gt----', '>', $md);
        $md = str_replace('<p><div', '<div', $md);
        $md = str_replace('class="note">', 'class="note"><p>', $md);
        $md = str_replace('<p></div></p>', '</div>', $md);
        // $md = str_replace('class="language-', 'class="code" id="', $md);
        $file_name = '<a href="#" style="float:right; margin:0.5em;" class="xyzzy"></a>';
        $copy_button = '<button style="float:right; margin:0.5em;" onclick="myCopy(this);return false;">Copy</button>';
        $edit_button = '<button style="float:right; margin:0.5em;" onclick="myEdit(this);return false;">Edit</button>';
        $md = str_replace('<pre><code class="language-', '<pre class="code">'.$edit_button.$copy_button.$file_name.'<code class="language-c" id="', $md);
        $pieces = explode("\n", $md);
        $new = array();
        foreach($pieces as $piece) {
            if (strpos($piece, "<h2>") === 0 ) {
                // Wow - the github h2 to anchor rules are complex
                // https://gist.github.com/asabaylus/3071099
                //   var anchor = val.trim().toLowerCase().replace(/[^\w\- ]+/g, ' ').replace(/\s+/g, '-').replace(/\-+$/, '');
                $title = str_replace("<h2>", "", $piece);
                $title = str_replace("</h2>", "", $title);
                $anchor = str_replace(".", "", $title);
                $anchor = str_replace("  ", " ", $anchor);
                $anchor = str_replace("  ", " ", $anchor);
                $anchor = str_replace(" - ", "--", $anchor);
                $anchor = str_replace(" ", "-", $anchor);
                $anchor = strtolower($anchor);
                $new[] = '<h2><a id="'.$anchor.'" class="anchor" aria-hidden="true" href="#'.$anchor.'"></a>' . $title . '</h2>';
            } else {
                $new[] = $piece;
            }
        }
        echo(implode("\n", $new));
    }
} else {
?>
<p>
This is a work in progress start here: 
<a href="chap01.md">Chapter 1</a>,
Please feel free to improve this text in 
<a href="https://github.com/csev/cc4e/tree/main/md" target="_blank">Github</a>.
</p>
<?php
}
?>
<div style="float:right">
<select id="chapters" onchange="onSelect('chapters');">
  <option <?= x_sel("..") ?>>CC4E</option>
  <option <?= x_sel("toc.md") ?>>Table of Contents</option>
  <option <?= x_sel("about.md") ?>>About</option>
  <option <?= x_sel("chap00.md") ?>>Chapter 0</option>
  <option <?= x_sel("chap01.md") ?>>Chapter 1</option>
  <option <?= x_sel("chap02.md") ?>>Chapter 2</option>
  <option <?= x_sel("chap03.md") ?>>Chapter 3</option>
  <option <?= x_sel("chap04.md") ?>>Chapter 4</option>
  <option <?= x_sel("chap05.md") ?>>Chapter 5</option>
  <option <?= x_sel("chap06.md") ?>>Chapter 6</option>
  <option <?= x_sel("chap07.md") ?>>Chapter 7</option>
  <option <?= x_sel("chap08.md") ?>>Chapter 8</option>
</select>
</div>
<br clear="all">
<hr/>
<small>
<blockquote>
<a href="https://en.wikipedia.org/wiki/The_C_Programming_Language" target="_blank"><img src="pages/front.jpg" style="width:150px; float:right; padding-left: 10px;"></a>
<p>
This work
(<a href="https://www.cc4e.com">www.cc4e.com</a>) is based on the 1978 
<a href="https://en.wikipedia.org/wiki/The_C_Programming_Language" target="_blank">"The C Programming Language"</a>
book written by Brian W. Kernighan and
Dennis M. Ritchie.  Their book
is copyright all rights reserved by AT&amp;T but is being used
in this work under "fair use" because of the book's historical and scholarly significance,
its lack of availability, and lack of an accessible version of the book.
</p>
<p>
The book is augmented in places to help understand its rightful place in a historical
context amidst the major changes of the 1970's and 1980's as Computer Science evolved from a
hardware-first / vendor-centered aproach to a software-centered approach where
portable operating systems and applications written in C could run on any hardware.
</p>
<p>
This is not the ideal book to learn C programming because the 1978 edition does not reflect the modern
C language.  Using an obsolete book gives us an opportunity to take students back in time and understand
how the C language was evolving as it laid the ground work for a future with portable applications.
</p>
<p>
If you want to learn modern C programming from a book that reflects the modern C language,
I suggest you use the
<a href="https://amzn.to/3hNp6QH" target="_blank">C Programming Language, 2nd Edition</a>,
also written by Brian W. Kernighan and Dennis M. Ritchie, initially published in
1988 and based on the 
<a href="https://en.wikipedia.org/wiki/ANSI_C" target="_blank">ANSI C</a> (C89) version
of the language.
</p>
<p>
The source code to this book is at 
<a href="https://github.com/csev/cc4e" target="_blank">https://github.com/csev/cc4e</a>.
You are welcome to help in the creation and editing of the book.
</blockquote>
</small>
<script>
$(document).ready(function() {
$("code.language-c").each(function( index ) {
  var filename = $( this ).attr("id");
  $(this).prev("a.xyzzy").attr('href', '#'+filename);
  filename = filename.replace('.c', '');
  $(this).prev("a.xyzzy").text(filename);
});
});
</script>
</body>