Author: Philip Hazel Date: To: Giuseppe Attardi CC: pcre-dev Subject: Re: [pcre-dev] obtaining pattern from a compiled re
On Thu, 17 Jun 2010, Giuseppe Attardi wrote:
> Is there a way to get back the original string pattern from a compiled pcre?
No. PCRE does not save the original string. It would be possible to
write a function that generates an equivalent string, but it would not
necessarily be the same as the original. For example, "a{0,}" might
become "a*" and "a{0}" might be omitted altogether, "[abcd]" might be
shown as "[a-d]". There are also optimizations: "a+b" would be shown as
"a++b", for example, because PCRE optimizes it that way.
If you run the pcretest program with the -d option, it shows you a form
of the compiled pattern, item by item, but not as a single string.
