In-depth explanation of PHP magic quotes

I checked the following manual. For php magic quotes, several common settings are as follows: magic_quotes_gpc, magic_quotes_sybase, and magic_quote_runtime. These functions are in php. from the manual, we can see that these features have been abolished since php5.3, So we strongly recommend that you do not use them in php. ini.

These functions are used to escape data. When SQL injection is prevented, many people write as follows:

Copy codeThe Code is as follows: if (! Get_magic_quotes_gpc ()){
$ Post = addslashes ($ post );
}

If they are enabled, they will automatically escape single quotes ('), double quotes ("), backslash (\), and NUL (null character). In fact, they are equivalent to calling the addslashes function. You may say this is not very good. It is more secure, but do you consider code portability? In addition, do you need to escape all gpc ($ _ GET, $ _ POST, $ _ COOKIE) data? What is the overhead? The following is a detailed description of Magic Quotes in the manual:

1. magic_quotes_gpc

Magic_quotes_gpc is used to set the magic reference status of GPC ($ _ GET, $ _ POST, $ _ COOKIE) ($ _ ENV is also included in PHP4 ). When it is enabled, all single-quote, double quotation marks, backslash, and NUL's will be automatically escaped by the backslash. When magic_quote_sybase is on enabled, only singgle-quote will be escaped as ''by single quotation marks, double quotation marks, backslash, and NUL's will not be affected.

2. magic_quote_runtime

Magic_quote_runtime if this option is enabled, many functions that return external data (Database, text) will be escaped by backslash. If magic_quote_sybase is enabled, only single-quotes are escaped.

3. magic_quotes_sybase

Magic_quotes_sybase if this option is enabled, when magic_quotes_gpc and magic_quotes_runtime are enabled, single quotation marks are transferred by single quotation marks instead of backslash \ escape. At the same time, this setting will completely overwrite the magic_quotes_gpc settings, even if magic_quotes_gpc is set to on, double quotation marks ", backslash \ and NUL's will not be escaped.