What is the reason why the PHP verification code is not displayed completely?

The reasons for the incomplete display of the php verification code: 1. The gd2 module is not installed in php; 2. It is probably edited using a text editor like editpuls or [notepad]; 3. Using [ob_clean() ], clear the cache.

The operating environment of this tutorial: Windows 7 system, PHP version 5.6, DELL G3 computer. This method is suitable for all brands of computers.

Reasons for incomplete display of php verification code:

(1) PHP does not have the gd2 module installed, you can use the phpinfo() function to view it.

(2) The code is most likely edited using a text editor like editpuls or notepad, then their default encoding format is utf-8 with BOM.

UTF-8 BOM is also called UTF-8 signature. In fact, UTF-8 BOM has no effect on UFT-8. It is added to support UTF-16 and UTF-32

BOM, BOM signature means to tell the editor what encoding the current file uses to facilitate the editor's identification. However, although the BOM is not displayed in the editor,

will produce output, just like an extra blank line. . Generally I use UTF-8 BOM-free format, so you need to change the encoding format of the code to BOM-free format.

(3) Use ob_clean() and clear the cache. There cannot be output before header().

The function ob_clean is used to discard the contents of the output buffer.

If you have many generated image files, you need to clear the buffer frequently if you want to access them correctly.

If the above three reasons have been checked and the verification code still cannot be displayed, another reason may be that the gd2 module was not actually installed successfully, and what is displayed in phpinfo() is an illusion.

In this case, reloading this module will not overwrite the broken one. You need to rebuild the environment and give it a try.

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