Here's a simple PHP diff script I wrote for no particular reason. Its output is similar to how Wikipedia does it, though admittedly, a lot simpler and inferior. It works really well for predictable comparisons, like two files that are mostly the same or a directory listing where some files have been renamed, added or removed. However, I have no use for it, I was simply trying for proof of concept. Even if I have no use for it, somebody might, right?
Anyway, here's how it works.
- It loads two files (any file and its older version.)
- It slits (or "explodes") each line into an array and counts the number of lines.
- It then compares each line of the current file to its older version.
-
If two lines match, the current file's line is displayed normally.
-
If two lines don't match it does the same process again, this time slitting each
word into an array and comparing them to the words in the old file's line.
- When two words don't match, the words from the current file's line are wrapped in HTML bold tags ("<b></b>") with a little style for color, and printed (or "echoed") on page.
-
If two lines don't match it does the same process again, this time slitting each
word into an array and comparing them to the words in the old file's line.
- It then reads and displays the old version of the file.
PHP Source Code:
<?php
// Copyright (C) 2012 Jacob Barkdull
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
//--------------------
//
// Script Description:
//
// A simple PHP diff script I wrote for no particular reason. Its
// output is similar to how Wikipedia does it, though admittedly, a
// lot simpler and inferior. It works really well for predictable
// comparisons, like two files that are mostly the same or a directory
// listing where some files have been renamed, added or removed.
// Display source code
if (basename ($_SERVER['PHP_SELF']) === basename (__FILE__)) {
if (isset ($_GET['source'])) {
header ('Content-type: text/plain; charset=UTF-8');
exit (file_get_contents (basename (__FILE__)));
}
}
// Replace '<' and '>' Characters
function replace ($input)
{
return str_replace (array ('<', '>'), array ('<', '>'), $input);
}
// Read files
$cf = replace (file_get_contents ('testdoc.txt')); // Current Version
$of = replace (file_get_contents ('testdoc_old.txt')); // Old Version
// Line Arrays
$cv = explode ("\n", $cf);
$ov = explode ("\n", $of);
// Count Lines - Set to Longer Version
$lc = (count ($cv) > count ($ov)) ? count ($cv) : count ($ov);
// Fix Mismatched Line Counts
for ($flc = count ($ov); $flc < $lc; $flc++) {
$ov[$flc] = '';
}
// Begin HTML Table
echo '<table width="100%">', "\n<tbody>\n<tr>\n";
// Begin diff column
echo '<td valign="top">', "\nCurrent Version:<hr>\n<pre>\n";
for ($l = 0; $l < $lc; $l++) {
// Word Arrays
$cw = explode (' ', $cv[$l]); // Current Version
$ow = explode (' ', $ov[$l]); // Old Version
// Count Words - Set to Longer Version
$wc = (count ($cw) > count ($ow)) ? count ($cw) : count ($ow);
// Fix Mismatched Word Counts
for ($fwc = count ($ow); $fwc < $wc; $fwc++) {
$ow[$fwc] = '';
}
// If each line is identical, just echo the normal line. If not,
// check if each word is identical. If not, wrap colored "<b>"
// tags around the mismatched words.
if ($cv[$l] !== $ov[$l]) {
for ($w = 0; $w < $wc; $w++) {
if ($cw[$w] === $ow[$w]) {
echo $cw[$w];
echo ($w !== ($wc - 1)) ? ' ' : "\n";
} else {
echo '<b style="color: #00BB00;">', $cw[$w];
echo ($w !== ($wc - 1)) ? '</b> ' : "</b>\n";
}
}
} else {
echo $cv[$l], "\n";
}
}
// End diff column
echo "</pre>\n</td>\n<td> </td>\n";
// Begin old version column
echo '<td valign="top">', "\nOld Version:<hr>\n<pre>\n";
echo $of, "\n";
// End old version column
echo "</pre>\n</td>\n";
// End HTML table
echo "</tr>\n</tbody>\n</table>";
Output:
|
Current Version:
This is the new file, Here's an unchanged line, This is totally awesome! And here's whole new line! |
Old Version:
This is the old file, Here's an unchanged line, This is completely aweful! |
If you think you could use this script for something, here is the source code: diff-script.php. If you make any changes, feel free to send them my way, someday I may need a script like this, so if you improve it that might mean a lot someday. Check out my other bits of code: here.
Let me know what you think in the comments. And enjoy!
