UTF-8 NO BOM & BOM

When you modify Ecshop, you may experience a problem with the BOM.

After the modifications are saved, the browser may appear:

Warning:cannot Modify header information-headers already sent ...


Bom


UTF-8 encoded files can be divided into no BOM and BOM two kinds of formats.

File using UTF8 encoding, when saving files, pay attention to the problem of the BOM.

Bom.
Quote:utf-8 is a byte-encoded unit with no byte-order problem. UTF-16 is a two-byte coding unit, before interpreting a UTF-16 text, first figure out the byte order of each encoding unit.

The recommended method of marking byte order in the Unicode specification is the BOM. The BOM is not a BOM for "Bill of Material", but "Byte order Mark".


If you choose to use a BOM when the file is saved, headers already sent problems may occur.
Because the WEB server Software may not know the BOM, so the two special bytes of the BOM as word Fu Fa to the browser.

Then call Session_Start () and other functions, there will be headers already sent problems.

So the most fundamental way to solve this problem is to not use a BOM when saving UTF8 encoded files.

Microsoft Notepad (Notepad) Word can only correctly open the UTF8 file containing the BOM, and then ultraedit on the contrary, back to the BOM UTF-8 file mistaken for ASCII encoding.

UTF-8 BOM is "EFBBBF", because the UE loading UTF-8 file will be converted into UTF16, the EFBBBF in Utf16 is Fffe (Unicode-le's BOM), UltraEdit do not know the BOM and add more than one BOM, So there are 2 Fffe. The file was destroyed by it.

In the WIN32 environment, PHP editors recommend using EditPlus, and the rest, such as Notepad2, is OK.

Further reading: http://zhidao.baidu.com/question/15626866.html