不是iconv函数的bug

函数原型：string iconv ( string $in_charset , string $out_charset , string $str )

特别是第二个参数说明：

The output charset.

If you append the string //TRANSLIT to out_charset transliteration is activated. This means that when a character can’t be represented in the target charset, it can be approximated through one or several similarly looking characters. If you append the string //IGNORE, characters that cannot be represented in the target charset are silently discarded. Otherwise, str is cut from the first illegal character and an E_NOTICE is generated.

意思是如果你在第二个参数后面加上//TRANSLIT ，这样的话，当遇到目标输出的编码不认识的字符的时候，能被一个或几个近似的字符代替；而如果在第二个参数后面加上//IGNORE的时候，当目标输出的编码不认识的时候则什么也不操作；什么都不加的时候则会报错~~~
手册里面有个非常生动的例子：

<?php
$text = "This is the Euro symbol '€'.";

echo 'Original : ', $text, PHP_EOL;
echo 'TRANSLIT : ', iconv("UTF-8", "ISO-8859-1//TRANSLIT", $text), PHP_EOL;
echo 'IGNORE : ', iconv("UTF-8", "ISO-8859-1//IGNORE", $text), PHP_EOL;
echo 'Plain : ', iconv("UTF-8", "ISO-8859-1", $text), PHP_EOL;

?>

输出结果是：
Original : This is the Euro symbol ‘€’.

TRANSLIT : This is the Euro symbol ‘EUR’.

IGNORE : This is the Euro symbol ”.

Plain :

Notice: iconv(): Detected an illegal character in input string in ./iconv-example.php on line 7

This is the Euro symbol ‘
这样就非常清楚了

这里总结几点教训：

第一：php最好的手册就是官方的在线收藏;

(网上下的php中文手册往往会不完整或者没有更新，开始就是因为我电脑上的php中文手册没有这几个参数的说明)

第二：别太相信百度、google的中文搜索结果，别人讲的不一定是对的~~

最好就是直接找最权威，最官方的说明~~