Content filtering is mostly intended to prevent some security injection or cross-origin operations. Let's take a look at several simple anti-injection content filtering program codes that I have compiled. I hope the article will be helpful to you.
Method 1: Filter useless content
You can find other filtering methods on the Internet:
| The Code is as follows: |
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Function checkHtml ($ data ){
$ Ret = preg_match ("/['.,:;*?~ '! @ # $ % ^ & + =) (<>{}] | [|/| \ | "|/", $ Data );
If ($ ret = 1 ){
Return false; exit;
} Else {
Return true;
}
} |
Example 2 filter some html tags
| The Code is as follows: |
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Function uh ($ str)
{
$ Farr = array (
"/S +/", // filter unnecessary Spaces
"/<(/?) (Scripti? Framestylehtmlbodytitlelinkmeta? %) ([^>] *?)> /IsU ", // filter <script and other code that may introduce malicious content or maliciously change the display layout. If you do not need to insert flash, you can also add <object Filtering
"/(<[^>] *) On [a-zA-Z] + s * = ([^>] *>)/isU ", // filter javascript on events
);
$ Tarr = array (
"",
"<\ 1 \ 2 \ 3>", // If You Want To directly clear insecure labels, leave it blank.
"\ 1 \ 2 ",
);
$ Str = preg_replace ($ farr, $ tarr, $ str );
Return $ str;
}
|
Method 3: The above two methods put the content to be filtered in the program. Below I will put the content to be filtered in a txt text, the first time I read the file content for judgment, this facilitates the maintenance of the content to be filtered.
| The Code is as follows: |
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<? Php
If ($ _ POST)
{
// You can convert the file content to an array:
/*
$ Fcon = file_get_contents ("./filter.txt ");
$ Filter_word = explode ("n", $ fcon );
*/
$ Filter_word = file ("./filter.txt ");
// $ Filter_word = array ("test1", "test2", "test3", "test4 ");
$ Str = $ _ POST ["mess"];
For ($ I = 0; $ I <count ($ filter_word); $ I ++)
{
If (preg_match ("/". (trim ($ filter_word [$ I]). "/I", $ str ))
{
Echo "<script> alert ('the content you entered contains illegal content. Please try again! '); </Script> ";
Echo "<a href = 'index. php'> return </a> ";
Exit;
}
}
Echo "the content you entered is:". $ str;
}
?>
<H2> test whether the filter is effective: <Form action = "<? Php echo $ _ SERVER ['php _ SELF '];?> "Method =" post ">
<P> <textarea name = "mess" cols = "40" rows = "4"> </textarea> </p>
<P> <input type = "submit" name = "sub" value = "send"> </p>
</Form> |
