blocks|key|3033354|text|这意味着当您向函数传递任意二进制数据(即包含非ASCII字节和/或空字节的字符串)时，该函数将正常工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3033355|例如，一个非二进制安全函数可能基于一个C函数，该C函数需要以null结尾的字符串，因此如果该字符串包含null字符，则该函数将忽略其后的任何字符。|3033356|这一点很重要，因为PHP不能清晰地将字符串和二进制数据分开。|3033357|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

It means the function will work correctly when you pass it arbitrary binary data (i.e. strings containing non-ASCII bytes and/or null bytes).

For example, a non-binary-safe function might be based on a C function which expects null-terminated strings, so if the string contains a null character, the function would ignore anything after it.

This is relevant because PHP does not cleanly separate string and binary data.

blocks|key|300152|text|其他用户已经提到了binary+safe的一般含义。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|300153|在PHP中，含义更为具体，仅指Michael给出的示例。|300154|PHP中的所有字符串都有一个关联的长度，即组成字符串的字节数。当函数操作字符串时，它可以：|300155|300156|依赖于以null结尾的字符串的长度，也就是说，在实际是字符串一部分的数据之后，将出现一个值为0的字节。|ordered-list-item|300157|300158|同样，引擎操作的所有字符串PHP变量也都以null结尾。依赖于2的函数的问题是，如果字符串本身包含一个值为0的字节，则操作它的函数将认为该字符串已在该点结束，并将忽略该点之后的所有内容。|300159|例如，如果PHP的strlen函数像C标准库strlen一样工作，那么这里的结果将是错误的：|300160|$str+=+"abc\x00abc";
echo+strlen($str);+//gives+7,+not+3!|code-block|syntax|javascript|300161|entityMap^0|9|B|0|0|0|0|1A|1|0|0|1H|1|0|9|6|M|6|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|12|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|13|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|14|8|@]|D|@]|E|$]]|$1|K|3|L|5|M|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|18|8|@]|D|@]|E|$]]|$1|O|3|P|5|6|7|19|8|@$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]]|D|@]|E|$]]|$1|S|3|T|5|U|7|1H|8|@]|D|@]|E|$V|W]]|$1|X|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]]|Y|$]]

The other users already mentioned what <code>binary safe</code> means in general.

In PHP, the meaning is more specific, referring only to what Michael gives as an example.

All strings in PHP have a length associated, which are the number of bytes that compose it. When a function manipulates a string, it can either:

<ol>
<li>Rely on that length meta-data.</li>
<li>Rely on the string being null-terminated, i.e., that after the data that is actually part of the string, a byte with value <code>0</code> will appear.</li>
</ol>

It's also true that all string PHP variables manipulated by the engine are also null-terminated. The problem with functions that rely on 2., is that, if the string itself contains a byte with value <code>0</code>, the function that's manipulating it will think the string has ended at that point and will ignore everything after that.

For instance, if PHP's <code>strlen</code> function worked like C standard library <code>strlen</code>, the result here would be wrong:

<pre><code>$str = "abc\x00abc";
echo strlen($str); //gives 7, not 3!
</code></pre>

blocks|key|3033383|text|更多示例：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3033384|<?php

++++$string1+=+"Hello";
++++$string2+=+"Hello\x00World";

++++//+This+function+is+NOT+!+binary+safe
++++echo+strcoll($string1,+$string2);+//+gives+0,+strings+are+equal.

++++//+This+function+is+binary+safe
++++echo+strcmp($string1,+$string2);+//+gives+<0,+$string1+is+less+than+$string2.

?>|code-block|syntax|javascript|3033385|\x表示十六进制表示法。请参阅：PHP+strings|CODE|3033386|0x00+=+NULL
0x04+=+EOT+(End+of+transmission)|3033387|查看ASCII字符列表的ASCII+table|3033388|entityMap|0|LINK|mutability|MUTABLE|url|http://ch.php.net/manual/en/language.types.string.php#language.types.string.syntax.double|1|http://www.asciitable.com/^0|0|5|0|0|0|2|G|B|0|0|0|C|B|1|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|15|8|@$9|16|A|17|B|M]]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|N|3|O|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|P|3|Q|5|6|7|1C|8|@]|D|@$9|1D|A|1E|1|1F]]|E|$]]|$1|R|3|-4|5|6|7|1G|8|@]|D|@]|E|$]]]|S|$T|$5|U|V|W|E|$X|Y]]|Z|$5|U|V|W|E|$X|10]]]]

More examples:

<pre><code>&lt;?php

 $string1 = "Hello";
 $string2 = "Hello\x00World";

 // This function is NOT ! binary safe
 echo strcoll($string1, $string2); // gives 0, strings are equal.

 // This function is binary safe
 echo strcmp($string1, $string2); // gives &lt;0, $string1 is less than $string2.

?&gt;
</code></pre>

<code>\x</code> indicates hexadecimal notation. See: <a href="http://ch.php.net/manual/en/language.types.string.php#language.types.string.syntax.double" rel="noreferrer">PHP strings</a>

<pre><code>0x00 = NULL
0x04 = EOT (End of transmission)
</code></pre>

<a href="http://www.asciitable.com/" rel="noreferrer">ASCII table</a> to see ASCII char list

In <code>PHP</code> what does it mean by a function being <code>binary-safe</code> ?

What makes them special and where are they typically used ?

In PHP what does it mean by a function being binary-safe?

在PHP中，函数是binary-safe是什么意思？它们的特殊之处是什么?它们通常在哪里使用？

问在PHP中，函数是二进制安全的是什么意思？
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