Ask MetaFilter questions tagged with regularexpressions

I just want to add a dash!

royalsong — Tue, 13 Oct 2009 13:33:24 -0800

I'm using the find and replace tool in dreamweaver, ultilizing Regular Expressions to find four numbers and a space and then 'replace' that expression with itself but add a dash. I have a series of years and descriptions, it looks something like this:

1991 Event Number 1
1992 Event Number 2
1994 Event Number 3
1997 Event Number 4

I want to turn that into:

1991
- Event Number 1

1992
- Event Number 2

1994
- Event Number 3

1997
- Event Number 4

I don't want to do it manually, because there's something like 200 some-odd dates. I've managed to deceiver a regular expression to find the year and space ([0-9][0-9][0-9][0-9] ) but I can't seem to get dreamweaver to replace the found expression with itself.

Is that possible? if not, is there any method I can use to find the 5th character in a line, or the first space in a line?

Any suggestions?

(fyi: the end document will be a html page.)

How can I get my two regex subexpressions to match repeatedly?

cowbellemoo — Sun, 12 Jul 2009 22:42:53 -0800

Regular Expressions: How can I get my two subexpressions to match repeatedly? Right now my pattern matches the first instances but refuses to match anything after it. I've spent a few hours looking at regex tutorials, examples, and fiddling with a regex tester program and I'm obviously not making the intuitive leap.

Here's my pattern (PHP) and my sample text.

I'm trying to pick the four sets of HREF locations and link text (the subexpressions)
out of the html soup. So far $matches contains the whole subsection, and only the first set of location/text that I want. I suspect my failure is that some portion of the expression isn't greedy. Right?

Please hope me!

Regex Help for Adding +14 to a Series

pinto — Wed, 18 Mar 2009 14:47:47 -0800

I'm trying to use Regular Expressions in Textmate to do a Find/Replace. The goal: Find id="1", id="2", id="3", etc. and Replace with a value of +14, so that I replace yields id="15", id="16", id="17" etc. Thank you! I don't mind doing the Finds/Replaces one at a time, so I'm not worried about greedy/reluctant, whatever. I just want a bit of an easier way to add +14 to a value.

So far I've been able to Find using id="*[0-9], but no luck for the Replace. Thanks mucho for any help!

Regexp seems great but how do I output the result?

ilike — Mon, 31 Mar 2008 08:28:56 -0800

I have a found out a regular expression that searches for a specific bit of text i want to extract from a html document (product names) in notepad++. Now i want to put all the matches of my expression in a new file. Can this be done? I tried using the macro recorder but didnt manage to find a solutions since it always go back to the first match. I also tried cygwin grep but never got it to work (I typed "grep 'expression' file" but it returned the whole lines, not only the match).

I also have excel if it will help.

Regex Alms for the Perl-less?

ChasFile — Fri, 28 Dec 2007 02:12:28 -0800

Help me composite some regex. (That phrasing makes this question sound way less nerdy than it is) Here's a regex to find some stuff between square brackets:
/\[[^\]]+\]/

Here's one that finds something like Alt: or alt. or Alternative: or alternate or Alternate: or Alternative or Alt.: or you get the idea [note it ends with \s+; it is important for my application that the "Alt___ " I'm testing for has white space at the end, and that I test for it. In the final answer we can test for that word boundary any way we like, we just need to make sure that we do.]:
/(A|a)lt(\.|ernat(e|ive))?:?\s+/

So what I need is a regular expression for "stuff between square brackets where the first thing inside the brackets will NOT match the second regex." Or "Stuff inside square brackets that begins with anything BUT alt or Alt. or Alternate or alternative: or alt.: or etc. etc.

I feel like this should be easy, but I never bothered to totally and completely grok regex, and obviously I'm hurting now because of it. I'd very much appreciate any help anyone could give, and in exchange you'll get co-author credit for the amazing piece of software that this thing will ultimately be a part of! ;-)

How to make regular expressions work with track changes?

Partial Law — Wed, 31 Oct 2007 09:42:09 -0800

How can I make Microsoft Word's Find-and-Replace feature work properly with regular expressions when Track Changes is on? I'm working on a document containing a significant number of citations with page ranges. Many of those page ranges are separated by hyphens, and I need them to be separated by en dashes instead.

So I'm using Find and Replace with regular expressions like so:
Find what: ([0-9]{1,5})-([0-9]{1,5})
Replace with: \1–\2

Here's the problem: If I run Replace All on the test sentence, "Read pages 35-66, 87-92, & 105-22," I get back "Read pages 35–66, 87–92, & 105–22." Perfect. But if I turn on Track Changes and run it, I get "Read pages 3566–, 8792–, & 10522–." I need these changes to be tracked. Am I doomed to doing them by hand?
I realize how this question looks to people who aren't grammar nerds or law students. Trust me when I say that there is a difference, that the difference matters, and that the changes have to be tracked.

Regex question

pealco — Sun, 21 Jan 2007 11:52:29 -0800

What's a regular expression to match and replace space characters between curly braces with under scores? In other words, turn something like:

blah blah blah {blah blah blah} blah

into:

blah blah blah blah_blah_blah blah

There can be any number of words between the curly braces.

Regular expressions to describe incoming search engine URLs?

WCityMike — Thu, 05 Jan 2006 09:56:13 -0800

HtAccessFilter: I’m seeking regular expressions to describe URLs that encompass search engines’ image and video search engines, but not the engines themselves, so that I can block said image and video search engines using “SetEnvIfNoCase Referer” in .htaccess. Also, I’m also seeking to block all incoming requests for one particular URL which is popular with these video and image search engines but which no longer exists – but I don’t want to serve them the normal 404. To be specific, I’m seeking to block most image and video search engines from my website, while not excluding the main search engines themselves (e.g., I want Google Images and all its regional variations blocked, but not Google itself; Yahoo Video Search, but not Yahoo; etc.). I managed to get a good variation for Google Images:

SetEnvIfNoCase Referer "^https?://(www\.)?images.google.(ae|at|be|ca|ch|cl|co\.hu|co\.il|co\.in|co\.jp|co\.kr|co\.nz|co\.th|co\.uk|co\.za|com|com\.ar|com\.au|com\.br|com\.fn|com\.gr|com\.hk|com\.mx|com\.my|com\.ph|com\.pr|com\.ru|com\.sg|com\.tr|com\.tw|com\.ua|de|dk|fi|fr|gr|ie|it|lv|nl|pl|pt|ro|se|sk)" DumbSearchEngine=1

However, I did that not through my own very bad knowledge of regular expressions, but by emulating what I saw elsewhere. I just don't have the know-how or the adequate reference to stave off the other search engines, really.

I’m now hoping others have worked out similar ways of describing and/or blocking things like AltaVista Video, Yahoo Video Search, and so on, without blocking Google, AltaVista, and Yahoo themselves. I also do not want to go too wide by blocking anything with ‘images’ or ‘video’ in the name itself, for example.

I then can direct them to a Forbidden error, so that they never even hit my StatCounter, which is the ultimate goal. I'm not a heavy multimedia website -- for some reason, if I am linking to an MP3 or AVI on another website, Yahoo, AltaVista, Google are all deciding that I'M hosting the image and linking their image- or video-search to me. Bastards.

Thanks.

(How|Where) does one find Google's (guide|help) on (searching|querying) using regular expressions?

Gyan — Thu, 28 Jul 2005 04:34:41 -0800

Well, what do you know, err.. what do I know, Google does support some sort of regular expressions. However, I can't find the usage guide. Anyone?

Using wildcards in virtusertable for sendmail: resources, pointers, and simple examples, please.

mwhybark — Wed, 07 Jul 2004 18:49:34 -0800

Using wildcards in virtusertable for sendmail: resources, pointers, and simple examples, please. Google-fu fails to provide examples that answer my questions. [emm eye] While the basic question, "Can I use wildcarded addresses at the server level with sendmail?" leads to the answer "of course, using vitusertable," the examples generally seen have broad scope:

myemail@somedomain.com -> %1@otherdomain.com

Compounding this is the sendmail-specific wildcarding scheme, which I still don't completely grok.

can I wildcard something like this?

[*+]foo[*+]@mydomain.com -> specificaddress@mydomain.com

(please note my also-primitive grasp of grep may mislead. I'm hoping that pseudo-address translates verbally to "any number and combination of characters on either or both sides of a specific string.")

So I think there are two parts here.

1. can I use virtusertable to set up subset-catchalls and direct them to the same domain?

2. can I get grep-style (grep-ish, what have you) wildcarding in virtusertable?

TIA!

Is there a regular expressions standard?

normy — Wed, 21 Apr 2004 17:09:36 -0800

Regular Expressions: Is there a standard? [more] Many programming languages and technologies support pattern matching in text using regular expressions. Is there a published industry standard somewhere for their syntax and implementation?