This feature has been DEPRECATED as of PHP 5.3.0. Relying on this feature is highly discouraged.
When on, all ' (single-quote), " (double quote), \ (backslash) and NULL characters are escaped with a backslash automatically. This is identical to what addslashes() does.
There are three magic quote directives:
magic_quotes_gpc Affects HTTP Request data (GET, POST, and COOKIE). Cannot be set at runtime, and defaults to on in PHP. See also get_magic_quotes_gpc().
magic_quotes_sybase If enabled, a single-quote is escaped with a single-quote instead of a backslash. If on, it completely overrides magic_quotes_gpc. Having both directives enabled means only single quotes are escaped as ''. Double quotes, backslashes and NULL's will remain untouched and unescaped. See also ini_get() for retrieving its value.