php 如何实现 git diff

无意间想到这个问题,如何用php来实现git diff,如果实现了这个功能,岂不是能够使用php对在线编辑文件的功能做更进一步的优化和提升?

查了一下还真有这样的库,话不多说,开始执行

composer require --dev sebastian/diff

得到结果

Info from https://repo.packagist.org: #StandWithUkraine
Using version ^5.0 for sebastian/diff
./composer.json has been created
Running composer update sebastian/diff
Loading composer repositories with package information
Updating dependencies
Lock file operations: 1 install, 0 updates, 0 removals
  - Locking sebastian/diff (5.0.1)
Writing lock file
Installing dependencies from lock file (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
  - Downloading sebastian/diff (5.0.1)
  - Installing sebastian/diff (5.0.1): Extracting archive
Generating autoload files
1 package you are using is looking for funding.
Use the `composer fund` command to find out more!

好,安装成功,创建index.php如下

<?php
include("./vendor/autoload.php");

use SebastianBergmann\Diff\Differ;
use SebastianBergmann\Diff\Output\UnifiedDiffOutputBuilder;

$builder = new UnifiedDiffOutputBuilder(
    "--- Original\n+++ New\n", // custom header
    true                      // do not add line numbers to the diff
);

$differ = new Differ($builder);
$before_string = file_get_contents("functions.php");
$after_string = file_get_contents("functions.php-new");
$diff_value = $differ->diff($before_string, $after_string);
echo $diff_value;

好,然后创建两个文件用来代表我们修改过文件的内容,修改之前的文件叫 functions.php 内容是

<?php

function get_rand_id ($id = 0) {
    static $id;
    if ($id) {
        return $id;
    }
    $id = rand(1, 1000);
    $id += 1000;
    return $id;
}

修改之后的文件叫 functions.php-new 内容是

<?php

function get_random_id (int $id = 0) {
    static $id;
    if (!$id) {
        $id = rand(1, 1000);
        $id = $id * $id;
    }
    return $id;
}

执行一下看看

php index.php &> diff.patch

得到结果

--- Original
+++ New
@@ -1,12 +1,11 @@
 <?php

-function get_rand_id ($id = 0) {
+function get_random_id (int $id = 0) {
     static $id;
-    if ($id) {
-        return $id;
+    if (!$id) {
+        $id = rand(1, 1000);
+        $id = $id * $id;
     }
-    $id = rand(1, 1000);
-    $id += 1000;
     return $id;
 }

那这样的结果呢也能作为patch查看,要怎么有更好的查看方式呢?

我们可以在vscode编辑器里面安装一个叫做 Diff Viewer 的插件 点击这里

安装完毕, 打开这个 diff.patch 文件后是这样的

怎么样,是不是很不错,有点像 git 的感觉了,哈哈哈