Escapes the special characters used for regular expressions in string, for instance "a.
b*c" becomes "a\.b\*c". This function is useful to dynamically generate regular expressions.
string can contain nul characters that are replaced with "\0", in this case remember to specify the correct length of
string in length.
| length |
the length of |
| string |
the string to escape |
|
a newly-allocated escaped string |