I am looking for alternate methods to get john from the provided example.
My expression works as is but was hoping for some examples of better methods.
Example: john&home
my regexp: [a-z]{3,6}[^&home]
Im matching any character of length 3-6 upto but not including &home
Every item i run the regexp on is in the same format. 3-6 characters followed by &home
I have looked at other posts but was hoping for a reply specific to my regexp.
Most regex engines allow you to capture parts of a regex with capture groups. For instance:
^([A-Za-z]{3,6})&home$
The brackets here mean that you are interested in the part before the &home. The ^ and $ mean that you want to match the entire string. Without it, averylongname&homeofsomeone will be matched as well.
Since you use rubular, I assume you use the Ruby regex engine. In that case you can for instance use:
full = "john&home"
name = full.match(/^([A-Za-z]{3,6})&home$/).captures
And name will in this case contain john.
Related
I'm attempting to setup Content Groupings using Extraction within Google Analytics.
I have URL's of the form http://www.ehattons.com/52674/Bachmann_Branchline_37_671_Pack_of_3_14_Ton_tank_wagons_in_Fina_livery_weathered/StockDetail.aspx
I wish to use Regex to say that only in cases where a URL contains /StockDetail.aspx, extract everything before the first underscore, excluding any digits. e.g. 'Bachmann'.
I've managed to source the following regex to return everything before the first underscore
^[^_]+(?=_).
However, that's as far as I can get with my limited understanding. Anyone know what regex will do the trick here?
Many thanks,
Well you did the halfway.
Think about it this way : you're looking for extracting something followed by a underscore but not following one when the string contain /StockDetail.aspx. You know that this part of string will always be after your first underscore.
So you start with no underscore before : [^_]
Then you create the group you want to match with ([a-zA-Z]*) (you cannot work with \w since it's including underscore). Your string has to be followed by a underscore so you add _ after your group. And finnaly somewhere in the url you've got /StockDetail.aspx. Your regex should look like this :
[^_]([a-zA-Z]*)_.*(?:\/StockDetail\.aspx)
Result
This is a string:
http://news.ycombinator.com/page?vasya=pupkin&b=b news.ycombinator.com/page news.ycombinator.com/page.php news.ycombinator.com/page
I am extracting a host with page. So I wrote the following regular expression:
([a-zA-Z0-9\.]*[a-zA-Z0-9]+[^\/][\.][a-zA-Z0-9\/\.]+)
It returns me these (in bold):
http://news.ycombinator.com/page?vasya=pupkin&b=b news.ycombinator.com/page news.ycombinator.com/page.php news.ycombinator.com/page
This is not exactly what I need. Regexp should not see a host with page in case of this string: http://news.ycombinator.com/page?vasya=pupkin&b=b, because it is a link, which should be treated differently.
Should be rejected:
"http://news.ycombinator.com/page?vasya=pupkin&b=b", "http://news.ycombinator.com/page", "http://news.ycombinator.com/","http://news.ycombinator.com".
Should not be rejected:
"news.ycombinator.com/page","news.ycombinator.com/page.php", "news.ycombinator.com/page/index", "news.ycombinator.com/page/index.php"
How to improve this regexp so it could select only those string parts, which have no word characters nearby?
I'm not sure exactly what you are using to do your regex, but you've actually solved your own problem - you just need the regex to match whole words. This will depend on the program you are using, but this is a guidleine (posix style regex):
([:space:][a-zA-Z0-9\.]*[a-zA-Z0-9]+[^\/][\.][a-zA-Z0-9\/\.]+[:space:])
or maybe ([:space:]([a-zA-Z0-9]*[\.\/])+[a-zA-Z0-9]+[:space:])
In the second one, you will have to make sure the inner groups are for non capturing groups.
I've seen the results for classifying verbs by their endings. But I want to use Regular Expressions to find verb roots for regular verbs in Spanish.
I'm using this fancy site: http://regexpal.com/
Which I suspect may not be compatible with my end use, but will be a great starting point.
From what I have seen, the caret should identify all strings after it based on your supplied string-pattern.
So, to me:
ˆgust
Should find "gusta", "gustan", "gustamos", "gustas","gustar".
I know that I'm way off, but looking at many of the pages and tutorials and examples, I don't see anything that looks similar to what I want to do.
When you look for regex matching you'll get only the matching part, meaning, in case you have the word "gustan" and you're trying to match it with ^gust like you suggested, the output of the matcher will be "gust" - which is not what you want (you want the whole word).
So instead of matching to ^gust try matching to ^gust\w*$ which means anything that starts with "gust" and has zero or more characters following it.
^(gust[a-zA-Z]*)$
Edit live on Debuggex
^ denotes the start of the line
[a-zA-Z] letters only
* means zero or more
() is called a capture group
$ is the end of the line
If you want to edit with different words you could do this...
^((?:gust|otherwords)[a-zA-Z]*)$
Edit live on Debuggex
all you have to change/edit is |otherwords this will allow you to add more words that you want to match.
please read more about regex here and use debugexx.com to experiment.
I need a regex to obfuscate emails in a database dump file I have. I'd like to replace all domains with a set domain like #fake.com so I don't risk sending out emails to real people during development. The emails do have to be unique to match database constraints, so I only want to replace the domain and keep the usernames.
I current have this regex for finding emails
\b[A-Z0-9._%-]+#[A-Z0-9.-]+\.[A-Z]{2,4}\b
How do I convert this search regex into a regex I can use in a find and replace operation in either Sublime Text or SED or Vim?
EDIT:
Just a note, I just realized I could replace all strings found by #[A-Z0-9.-]+\.[A-Z]{2,4}\b in this case, but academically I am still interested in how you could treat each section of the email regex as a token and replace the username / domain independently.
SublimeText
SublimeText uses Boost syntax, which supports quite a large subset of features in Perl regex. But for this task, you don't need all those advanced constructs.
Below are 2 possible approaches:
If you can assume that # doesn't appear in any other context (which is quite a fair assumption for normal text), then you can just search for the domain part #[A-Z0-9.-]+\.[A-Z]{2,4}\b and replace it.
If you use capturing groups (pattern) and backreference in replacement string.
Find what
\b([A-Z0-9._%-]+)#[A-Z0-9.-]+\.[A-Z]{2,4}\b
([A-Z0-9._%-]+) is the first (and only) capturing group in the regex.
Replace with
$1#fake.com
$1 refers to the text captured by the first capturing group.
Note that for both methods above, you need to turn off case-sensitivity (indicated as the 2nd button on the lower left corner), unless you specifically want to remove only emails written in ALL CAPS.
You may use the following command for Vim:
:%s/\(\<[A-Za-z0-9._%-]\+#\)[A-Za-z0-9.-]\+\.[A-Za-z]\{2,4}\>/\1fake.com/g
Everything between \( and \) will become a group that will be replaced by an escaped number of the group (\1 in this case). I've also modified the regexp to match the small letters and to have Vim-compatible syntax.
Also you may turn off the case sensitivity by putting \c anywhere in your regexp like this:
:%s/\c\(\<[A-Z0-9._%-]\+#\)[A-Z0-9.-]\+\.[A-Z]\{2,4}\>/\1fake.com/g
Please also note that % in the beginning of the line asks Vim to do the replacement in a whole file and g at the end to do multiple replacements in the same line.
One more approach is using the zero-width matching (\#<=):
:%s/\c\(\<[A-Z0-9._%-]\+#\)\#<=[A-Z0-9.-]\+\.[A-Z]\{2,4}\>/fake.com/g
How I can get part of SIP URI?
For example I have URI sip:username#sip.somedomain.com, I need get just username and I use [^sip:](.*)[$#]+ expression, but appeared result is username#. How I can exclude from matching #?
this should do the job
(?<=^sip:)(.*)(?=[$#])
Use a lookahead instead of actually matching #:
^sip:(.*?)(?=#|\$)
Either you are using a very strange regex flavor, or your starting character class is a mistake. [^sip:] matches a single character that isn't any of s,i,p or :. I am also not certain what the $ character is for, since that isn't a part of SIP syntax.
If lookaheads are not available in your regex flavour (for instance POSIX regexes lack them), you can still match parts of the string in your regex you don't eventually want to return, if you use capture groups and only grab the contents of some of them.
For example
^sip:(.*?)[$#]+ Then only return the contents of the first capture group