sha1_file

名称:sha1_file

分类:字符串

所属语言:php

一句话介绍:计算文件的 SHA-1 散列。

实例

例子 1

计算文本文件 "test.txt" 的 SHA-1 散列：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$filename</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"test.txt"</span><span class="token punctuation">;</span>
<span class="token variable">$sha1file</span> <span class="token operator">=</span> <span class="token function">sha1_file</span><span class="token punctuation">(</span><span class="token variable">$filename</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$sha1file</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

以上代码的输出：

aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d

例子 2

在文件中存储 "test.txt" 的 SHA-1 散列：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$sha1file</span> <span class="token operator">=</span> <span class="token function">sha1_file</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"test.txt"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">file_put_contents</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"sha1file.txt"</span><span class="token punctuation">,</span><span class="token variable">$sha1file</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

测试 "test.txt" 是否已被修改（即 SHA-1 是否已被修改）：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$sha1file</span> <span class="token operator">=</span> <span class="token function">file_get_contents</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"sha1file.txt"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token function">sha1_file</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"test.txt"</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token variable">$sha1file</span><span class="token punctuation">)</span>
  <span class="token punctuation">{</span>
  <span class="token keyword">echo</span> <span class="token string double-quoted-string">"The file is ok."</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
<span class="token keyword">else</span>
  <span class="token punctuation">{</span>
  <span class="token keyword">echo</span> <span class="token string double-quoted-string">"The file has been changed."</span><span class="token punctuation">;</span>
  <span class="token punctuation">}</span>
<span class="token delimiter important">?></span></span>

以上代码的输出：