preg_quote() takes str
and puts a backslash in front of every character that is part of
the regular expression syntax. This is useful if you have a
run-time string that you need to match in some text and the
string may contain special regex characters.
If the optional delimiter
is specified, it
will also be escaped. This is useful for escaping the delimiter
that is required by the PCRE functions. The / is the most commonly
used delimiter.
The special regular expression characters are: . \ + * ? [ ^ ] $ ( ) { } = ! < > | :
Note: This function is binary-safe.