<?php

$file2 = "httpd.conf";
$file1 = $file2 .".old";


    function GiveToMe( $filename1, $filename2 )
    {
	$diff = array();
	$command = "diff -u ". $filename1 . " ". $filename2;
	//echo $command;
	$diffstream = popen( $command, "r" );
	//echo $diffstream;
	while ($line = fgets($diffstream, 4096)) {
		$diff[] = rtrim($line);
	}
	return humanReadable($diff);
    }


    /*
     * Obtain a tree containing information about the changes between two
     * revisions.
     * @param raw The raw unified diff, normally obtained through CVSLib_Diff::get()
     * @return TODO: document this thoroughly, as the format is a bit complex
     */
    function humanReadable(&$raw) {
        $ret = array();

        /* Hold the left and right columns of lines for change blocks */
        $cols = array( array(), array() );
        $state = CVSLIB_DIFF_EMPTY;

        /* Iterate through every line of the diff */
        foreach ($raw as $line) {

            /* Look for a header which indicates the start of a diff chunk */
            if (preg_match('/^@@ \-([0-9]+).*\+([0-9]+).*@@(.*)/', $line, $regs)) {
               /* Push any previous header information to the return stack */
               if (isset($data)) $ret[] = $data;
               $data = array('type' => CVSLIB_DIFF_HEADER, 'oldline' => $regs[1],
                             'newline' => $regs[2], 'contents'> array());
               $data['function'] = isset($regs[3])?$regs[3]:'';
               $state = CVSLIB_DIFF_DUMP;

            } else if ($state != CVSLIB_DIFF_EMPTY) {
               /* We are in a chunk, so split out the action (+/-) and the line */
               preg_match('/^([\+\- ])(.*)/', $line, $regs);
               if (sizeof($regs) > 2) {
                   $action = $regs[1];
                   $content = $regs[2];
               } else {
                   $action = ' ';
                   $content = '';
               }

               if ($action == '+') {
                   /* This is just an addition line */
                   if ($state == CVSLIB_DIFF_DUMP || $state == CVSLIB_DIFF_ADD) {
                       /* Start adding to the addition stack */
                       $cols[0][] = $content;
                       $state = CVSLIB_DIFF_ADD;
                   } else {
                   /* This is inside a change block, so start accumulating lines */
                       $state = CVSLIB_DIFF_CHANGE;
                       $cols[1][] = $content;
                   }

               } else if ($action == '-') {
                   /* This is a removal line */
                   $state = CVSLIB_DIFF_REMOVE;
                   $cols[0][] = $content;

               } else {
                   /* An empty block with no action */
                   switch ($state) {
                     case CVSLIB_DIFF_ADD:
                       $data['contents'][] = array('type' => CVSLIB_DIFF_ADD, 'lines' => $cols[0]);
                       break;
                     case CVSLIB_DIFF_REMOVE:
                       /* We have some removal lines pending in our stack, so flush them */
                       $data['contents'][] = array('type' => CVSLIB_DIFF_REMOVE, 'lines' => $cols[0] );
                       break;
                     case CVSLIB_DIFF_CHANGE:
                       /* We have both remove and addition lines, so this is a change block */
                       $data['contents'][] = array('type' => CVSLIB_DIFF_CHANGE, 'old' => $cols[0], 'new' => $cols[1]);
                       break;
                   }
                   $cols = array( array(), array() );
                   $data['contents'][] = array('type' => CVSLIB_DIFF_EMPTY, 'line' => $content);
                   $state = CVSLIB_DIFF_DUMP;
               }
            }
        }

        /* Just flush any remaining entries in the columns stack */
        switch ($state) {
          case CVSLIB_DIFF_ADD:
            $data['contents'][] = array('type' => CVSLIB_DIFF_ADD, 'lines' => $cols[0]);
            break;
          case CVSLIB_DIFF_REMOVE:
            /* We have some removal lines pending in our stack, so flush them */
            $data['contents'][] = array('type' => CVSLIB_DIFF_REMOVE, 'lines' => $cols[0] );
            break;
          case CVSLIB_DIFF_CHANGE:
            /* We have both remove and addition lines, so this is a change block */
            $data['contents'][] = array('type' => CVSLIB_DIFF_CHANGE, 'old' => $cols[0], 'new' => $cols[1]);
            break;
        }

        if (isset($data)) {
            $ret[] = $data;
        }

        return $ret;
    }

function dRow( $lefthead, $righthead, $headfunc )
{
	?>

<tr><td class="separator" colspan=2>&nbsp;</td></tr>
<tr class="hr-diff-linenum">
 <td width="50%" class="hr-diff-linenumcell" >
   &nbsp; <b><?= sprintf(_("Line %s"), $lefthead) ?> </b>
   &nbsp;<?= $headfunc ?>
 </td>
 <td width="50%" class="hr-diff-linenumcell" >
   &nbsp; <b><?= sprintf(_("Line %s"), $righthead) ?> </b>
   &nbsp;<?= $headfunc ?>
 </td>
</tr>
	<?php
}
function dAdd( $line )
{

	?>
<tr>
 <td class="hr-diff-grey">&nbsp;</td>
 <td class="hr-diff-add" title="ADDED"><tt><?= !empty($line) ? $line : '&nbsp;' ?></tt></td>
</tr>
	<?php
}

function dRemove( $line )
{
	?>

<tr>
  <td class="hr-diff-remove">
    <tt><?= $line ?></tt>
  </td>
  <td class="hr-diff-grey">&nbsp;</td>
</tr>
	<?php
}
function dChange( $left, $right )
{
	?>

<tr>
<?php if (!empty($left)): ?>
  <td class="hr-diff-change">
   <tt><?= $left ?></tt>
  </td>
<?php else: ?>
  <td class="hr-diff-nochange">&nbsp;</td>
<?php endif; ?>
<?php if (!empty($right)): ?>
  <td class="hr-diff-change">
   <tt><?= $right ?></tt>
  </td>
<?php else: ?>
  <td class="hr-diff-nochange">&nbsp;</td>
<?php endif; ?>
</tr>
	<?php
}
function dEmpty( $line )
{
	?>

<tr class="hr-diff-context">
 <td><tt><?= $line ?></tt></td>
 <td><tt><?= $line ?></tt></td>
</tr>

	<?php
}


?>

<style>
.hr-diff-linenum { background-color: #FFF; font-size: 75%; }
.hr-diff-linenumcell { background-color: #AAA; }
.hr-diff-grey    { background-color: #EEE; border: dashed black thin; }
.hr-diff-add     { background-color: #DFD; }
.hr-diff-change  { background-color: #DDF; }
.hr-diff-nochange{ background-color: #202; }
.hr-diff-context { background-color: #FFF; }
.hr-diff-remove  { background-color: #FDD; }
.separator       { border-bottom: dashed black thin; margin-top:5px; }
</style>
<table class="difftable" cellspacing=0 cellpadding=0 border=0>
<tr><TH>OLD</TH><TH>NEW</TH></TR>

<?php

$lns = GiveToMe( $file1, $file2 );

/* Iterate through every header block of changes */
foreach ($lns as $header) {
    $lefthead = htmlspecialchars(@$header['oldline']);
    $righthead = htmlspecialchars(@$header['newline']);
    $headfunc = htmlspecialchars(@$header['function']);
    dRow( $lefthead, $righthead, $headfunc );
    
    /* Each header block consists of a number of changes (add, remove, change) */
    foreach ($header['contents'] as $change) {
	switch ($change['type']) {
	case CVSLIB_DIFF_ADD:
	    foreach ($change['lines'] as $line) {
		$line = htmlspecialchars($line);
		dAdd( $line );
	    }
	    break;
	case CVSLIB_DIFF_REMOVE:
	    foreach ($change['lines'] as $line) {
		$line = htmlspecialchars($line);
		dRemove( $line );
	    }
	    break;
	case CVSLIB_DIFF_EMPTY:
	    $line = htmlspecialchars($change['line']);
	    dEmpty( $line );
	    break;
	case CVSLIB_DIFF_CHANGE:
	    /* Pop the old/new stacks one by one, until both are empty */
	    while (sizeof($change['old']) || sizeof($change['new'])) {
		if ($left = array_shift($change['old'])) {
		    $left = htmlspecialchars($left);
		}
		if ($right = array_shift($change['new'])) {
		    $right = htmlspecialchars($right);
		}
		dChange( $left, $right );
	    }
	    break;
	}
    }
}
echo '</table>';
?>