[英]How can I replace all hex using RegEx in PHP?
So I've been toying around with Regular Expressions, and my friend challenged me to write a script that replaced all hex within a string. 所以我一直在玩正则表达式,我的朋友挑战我写一个脚本替换字符串中的所有十六进制。 He gave me a large file mixed with different characters and, of course, some hex strings. 他给了我一个混合了不同字符的大文件,当然还有一些十六进制字符串。
Each occurrence of hex is preceded with \\x
, so for example: \\x55
. 每次出现的十六进制都以\\x
\\x55
,例如: \\x55
。
I thought it'd be pretty easy, so I tried out this pattern on some online regex tester: /\\\\x([a-fA-F0-9]{2})/
我认为这很简单,所以我在一些在线正则表达式测试器上尝试了这种模式: /\\\\x([a-fA-F0-9]{2})/
It worked perfectly. 它工作得很好。
However, when I throw it into some PHP code, it fails to replace it at all. 但是,当我把它扔进一些PHP代码时,它根本无法替换它。
Can anyone give me a nudge into the right direction of where I'm going wrong? 任何人都可以给我一个正确的方向,我错了吗?
Here's my code: 这是我的代码:
$toDecode = file_get_contents('hex.txt');
$pattern = "/\\x(\w{2})/";
$replacement = 'OK!';
$decoded = preg_replace($pattern, $replacement, $toDecode);
$fh = fopen('haha.txt', 'w');
fwrite($fh, $decoded);
fclose($fh);
<?php
// grab the encoded file
$toDecode = file_get_contents('hex.txt');
// create a method to convert \x?? to it's character facsimile
function escapedHexToHex($escaped)
{
// return 'OK!'; // what you're doing now
return chr(hexdec($escaped[1]));
}
// use preg_replace_callback and hand-off the hex code for re-translation
$decoded = preg_replace_callback('/\\\\x([a-f0-9]{2})/i','escapedHexToHex', $toDecode);
// save result(s) back to a file
file_put_contents('haha.txt', $decoded);
For reference, preg_replace_callback . 供参考, preg_replace_callback 。 Also, don't use \\w
as it's actually translated to [a-zA-Z0-9_]
. 另外,不要使用\\w
因为它实际上已翻译为[a-zA-Z0-9_]
。 Hex is base-16, so you want [a-fA-F0-9]
(and the i
flag makes it case-insensitive). 十六进制是base-16,所以你想要[a-fA-F0-9]
(并且i
标志使它不区分大小写)。
Working example , minus the file part. 工作示例 ,减去文件部分。
Your problem is that you have not escaped your backslashes in the PHP string. 您的问题是您没有在PHP字符串中转义反斜杠。 It needs to be: 它需要是:
$pattern = "/\\\\x(\\w{2})/";
...or:
...要么:
$pattern = '/\\\\x(\\w{2})/';
...with single quotes.
......用单引号。
- This actually suffers the same problem and requires the full double-escaped sequence - 这实际上遇到了同样的问题,需要完整的双重转义序列
But \\w
will match any perl word character, which is not just hex characters. 但是\\w
将匹配任何perl单词字符,这不仅仅是十六进制字符。 I would use the character class [a-fA-F0-9]
instead. 我会改用字符类[a-fA-F0-9]
。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.