SED regular expressions trouble

Question

I have build the following regular expression in order to fix a big sql dump with invalid tags This searches

\[ame=(?:\\"){0,1}(?:http://){0,1}(http://(?:www.|uk.|fr.|il.|hk.){0,1}youtube.com/watch\?v=([^&,",\\]+))[^\]]*\].+?video\]|\[video\](http://(?:www.|uk.|fr.|il.|hk.){0,1}youtube.com/watch\?v=([^\[,&,\\,"]+))\[/video\]

This replaces

[video=youtube;$2$4]$1$3[/video]

So this:

[ame=\"http://www.youtube.com/watch?v=FD5ArmOMisM\"]YouTube - Official Install Of X360FDU![/video]

will become

[video=youtube;FD5ArmOMisM]http://www.youtube.com/watch?v=FD5ArmOMisM[/video]

It behaves like a charm in EditPadPro (Windows) but it gives me conflicts with the codepages when I try to import it in my Linux based MySQL. So since the file comes from a Linux installation I tried my luck with SED but it gives me errors errors errors. Obviously it has a different way to build regular expressions.

It is quite urgent to do the substitutions so I have no time reading the SED manual.

Can you give a hand to migrate my regular expressions to a SED friendly format?

Thanx in advance!

UPDATE: I added the escape chars proposed

\[ame=\(?:\\"\)\{0,1\}\(?:http:\/\/\)\{0,1\}\(http:\/\/\(?:www.|uk.|fr.|il.|hk.\)\{0,1\}youtube.com\/watch\?v=\([^&,",\\]+\))[^\]]*\].+?video\]|\[video\]\(http:\/\/\(?:www.|uk.|fr.|il.|hk.\)\{0,1\}youtube.com\/watch\?v=\([^\[,&,\\,"]+\))\[\/video\]

but I still get errors - Unkown command: ')'

Answer 1

Sed just has some different escaping rules to the Regex flavor you're using.

• () escaped \( \) - for grouping
• [] are not - for character classes
• {} escaped \{ \} - for numerators

---

\[ame=\(?:\\"\)\{0,1\}\(?:http:\/\/\)\{0,1\}\(http:\/\/\(?:www.|uk.|fr.|il.|hk.\)\{0,1\}youtube.com\/watch\?v=\([^&,",\\]+\)\)[^\]]*\].+?video\]|\[video\]\(http:\/\/\(?:www.|uk.|fr.|il.|hk.\)\{0,1\}youtube.com\/watch\?v=\([^\[,&,\\,"]+\)\)\[\/video\]

I noticed a couple of unescaped )'s on enclosing groups.

Answer 2

Your regular expressions are using PCRE - Perl Compatible Regular Expression - notations. As defined by POSIX (codifying what was standardized by 7th Edition Unix circa 1978, which was a continuation of the previous versions of Unix), sed does not support PCRE.

Even GNU sed version 4.2.1, which supports ERE (extended regular expressions) as well as BRE (basic regular expressions) does not support PCRE.

Your best bet is probably to use Perl to provide you with the PCRE you need. Failing that, take the scripting language of your choice with PCRE support.