Comments on: Regexp with boost http://flavio.castelli.name/regexp-with-boost debugging my life Sat, 28 Jan 2012 07:37:17 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Francesco http://flavio.castelli.name/regexp-with-boost/comment-page-1#comment-13586 Francesco Fri, 01 Jul 2011 20:26:50 +0000 http://www.flavio.castelli.name/regexp-with-boost/#comment-13586 Sure, but you need to have in mind that regex can only be applied over patterns that can be matched against an expression. In case you need to find the second parameter from any string like: "aa 00 b0 aaaaa a 123455" I just need a regex like: ^[0-9a-f ]{1,59}\s([0-9a-f]{1,59}) It will match any line starting with a string that has numbers or letters (at least 1 and a maximum of 59), followed by space and having a second string, this is the group you need, so you just surround it with '(' and ')'. Sure, but you need to have in mind that regex can only be applied over patterns that can be matched against an expression. In case you need to find the second parameter from any string like:
“aa 00 b0 aaaaa a 123455″
I just need a regex like:
^[0-9a-f ]{1,59}\s([0-9a-f]{1,59})

It will match any line starting with a string that has numbers or letters (at least 1 and a maximum of 59), followed by space and having a second string, this is the group you need, so you just surround it with ‘(‘ and ‘)’.

]]> By: Francesco http://flavio.castelli.name/regexp-with-boost/comment-page-1#comment-13585 Francesco Fri, 01 Jul 2011 19:51:06 +0000 http://www.flavio.castelli.name/regexp-with-boost/#comment-13585 Yes, there is! You should use an conditional to check the group under test, like this: If you "castelli" or "(castelli)" its ok, but it should not match "(castelli" or "castelli)", to do so, you just make an expression like this: (\()?castelli(?(1)\)) The (1) is related to the first group, it means that if the group 1 - (\)) - exists, the second condition should be tested too. I think it can help on taking care about parenthesis in this case. Yes, there is!
You should use an conditional to check the group under test, like this:
If you “castelli” or “(castelli)” its ok, but it should not match “(castelli” or “castelli)”, to do so, you just make an expression like this:
(\()?castelli(?(1)\))

The (1) is related to the first group, it means that if the group 1 – (\)) – exists, the second condition should be tested too. I think it can help on taking care about parenthesis in this case.

]]> By: caneta http://flavio.castelli.name/regexp-with-boost/comment-page-1#comment-13406 caneta Wed, 01 Jun 2011 15:51:11 +0000 http://www.flavio.castelli.name/regexp-with-boost/#comment-13406 But if I have a string with a lot of useless blanks and tabs like mystr = " 1 4 999 3 67 ", is there a way to reproduce awk behaviour (like "cat mystr | awk '{ print $2 }'", obtaining 4 ) with boost/regex libraries? But if I have a string with a lot of useless blanks and tabs like mystr = ” 1 4 999 3 67 “, is there a way to reproduce awk behaviour (like “cat mystr | awk ‘{ print $2 }’”, obtaining 4 ) with boost/regex libraries?

]]> By: Xupicor http://flavio.castelli.name/regexp-with-boost/comment-page-1#comment-13032 Xupicor Tue, 25 Jan 2011 12:25:28 +0000 http://www.flavio.castelli.name/regexp-with-boost/#comment-13032 Maybe count matched '(' and ')' chars, and if the count_of_open == count_of_closed then the syntax is correct. Maybe count matched ‘(‘ and ‘)’ chars, and if the count_of_open == count_of_closed then the syntax is correct.

]]> By: Emre http://flavio.castelli.name/regexp-with-boost/comment-page-1#comment-10600 Emre Wed, 31 Mar 2010 21:54:32 +0000 http://www.flavio.castelli.name/regexp-with-boost/#comment-10600 Is there a way to accomplish parantheses matching like (((catelli))) For example this one is not correct: (((catelli) since there is only one at the right. Is it possible to detect this with regex_match ? Is there a way to accomplish parantheses matching like (((catelli)))
For example this one is not correct: (((catelli) since there is only one at the right. Is it possible to detect this with regex_match ?

]]>