PHP iconv() character encoding conversion problem_PHP tutorial

There is a function in the PHP function library: iconv(). The iconv function library can complete the conversion between various character sets and is an indispensable basic function library in PHP programming.

I am currently working on a thief program. I need to use the iconv function to convert the captured utf-8 encoded pages into gb2312. I found that only by using the iconv function to transcode the captured data, the data will be lost for no reason. less. I was depressed for a while. After checking the information on the Internet, I found out that this was a bug in the iconv function. iconv will make an error when converting the character "-" to gb2312.

Let’s take a look at the usage of this function.

The simplest application, replace gb2312 with utf-8:

$text=iconv("GB2312","UTF-8",$text);

In the process of using $text=iconv("UTF-8", "GB2312", $text), if you encounter some special characters, such as: "—", "." in English names, etc. , the conversion is interrupted. The text after these characters cannot be converted further.

To solve this problem, you can use the following code:

$text=iconv("UTF-8","GBK",$text);

You read that right, it’s that simple, just don’t use gb2312 and write it as GBK.

There is another method, add //IGNORE as the second parameter and ignore errors, as follows:

iconv("UTF-8","GB2312//IGNORE",$data);

There is no specific comparison between these two methods. I feel that the first method (GBK instead of gb2312) is better.

Instructions for iconv() in the php manual:

iconv
 
(PHP 4 >= 4.0.5, PHP 5)
iconv – Convert string to requested character encoding
Description
string iconv ( string in_charset, string out_charset, string str )
Performs a character set conversion on the string str from in_charset to out_charset. Returns the converted string or FALSE on failure.
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.

When using this function to convert string encoding, please note that if you convert utf-8 to gb2312, the string may be truncated. At this time, you can use the following methods to solve it:

$str=iconv('utf-8',"gb2312//TRANSLIT",file_get_contents($filepath));

That is, add the red part in the second parameter, which means: if no characters matching the source encoding are found in the target encoding, similar characters will be selected for conversion. You can also use the //IGNORE parameter here to ignore characters that cannot be converted.

ignore means to ignore errors during conversion. Without the ignore parameter, all strings following this character cannot be saved.

iconv is not the default function of PHP, and it is also a module installed by default. It needs to be installed before it can be used.

If it is windows2000+php, you can modify the php.ini file and remove the ";" before extension=php_iconv.dll. At the same time, you need to copy the iconv.dll in your original php installation file to your winnt/ Under system32 (if your dll points to this directory). In the Linux environment, using static installation, just add an additional item --with-iconv when configure. The iconv item can be seen in phpinfo. (Linux7.3+Apache4.06+php4.3.2).

Introduction to mb_convert_encoding and iconv functions

mb_convert_encoding This function is used to convert encoding. I used to not understand the concept of program coding, but now I seem to understand a little bit. However, English generally does not have encoding problems, only Chinese data will have this problem. For example, when you use Zend Studio or Editplus to write a program, you use gbk encoding. If the data needs to be entered into the database, and the database encoding is utf8, then the data must be encoded and converted, otherwise it will become garbled when entering the database. .

Make a GBK To UTF-8:

<?php 
header("content-Type: text/html; charset=Utf-8"); 
echo mb_convert_encoding("妳係我的友仔", "UTF-8", "GBK"); 
?> 

Another GB2312 To Big5:

<?php 
header("content-Type: text/html; charset=big5"); 
echo mb_convert_encoding("你是我的朋友", "big5", "GB2312"); 
?> 

However, to use the above function, you need to install and enable the mbstring extension library first.

string mb_convert_encoding (string str, string to_encoding [, mixed from_encoding]) You need to enable the mbstring extension library first. In php.ini, remove the ; extension=php_mbstring.dll in front of mb_convert_encoding. You can specify multiple input encodings, and it will Automatic recognition based on content, but the execution efficiency is much worse than iconv;

string iconv (string in_charset, string out_charset, string str) Note: In addition to specifying the encoding to be converted to, the second parameter can also add two suffixes: //TRANSLIT and //IGNORE, where // TRANSLIT will automatically convert characters that cannot be converted directly into one or more approximate characters. //IGNORE will ignore characters that cannot be converted, and the default effect is to truncate from the first illegal character.

In general, use iconv. Only use the mb_convert_encoding function when you are unable to determine what the original encoding is, or when iconv cannot be displayed normally after conversion.

$content = iconv("GBK", "UTF-8″, $content);
$content = mb_convert_encoding($content, "UTF-8″, "GBK");

http://www.bkjia.com/PHPjc/752405.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/752405.htmlTechArticleThere is a function in the php function library: iconv(). The iconv function library can complete conversion between various character sets. , is an indispensable basic function library in PHP programming. I'm currently working on a thief program, which requires...