I've been banging my head with this issue as I can't get this expression to work.
I'm trying to match and output a specific word from a string, so for example, take this string:
<ANIMALS>
<value>DOG CAT COW</value>
</ANIMALS>
And now I want to match any one of them and return that value otherwise none, let's say, COW.
I've tried a lot of varying expressions with no luck such as:
IF(VALUE == "/(^|\W)COW($|\W)/", "COWVALUE", "NONE")
This doesn't work, nor do any other variants I've tried. If I keep the original string as a single word and no actual calling expression, just a word, then it always works. As soon as I introduce a string of words then I can't make it happen.
Could anyone help please?
Thanks!
Get rid of (^|\W) and ($|\W), since that only matches at word boundaries, but you want to match COW when it's not by itself as a word. The regular expression should just be /COW/, it will match that string wherever it appears in the string.
BTW, to match word boundaries you can use \b rather than those alternations.
Not sure what programming language you're using but following is a simple example based in Javascript to do achieve your goals.
regex demo
Related
I have a special task which requires lots of regex and javascript parsing.
My head is almost exploding, so maybe I'm tired and forgot some small thing else I'm not newbie to regex so perhaps someone will point me to good direction here and show me where I did mistake.
So I have this regex code:
((?<=\ffmpg=).+(?=////u0026cs=nt))
to get the value of substring between 2 strings. The first string is called:
ffmpg= from this string it should start and it will end just before the other string start called //u0026cs=nt
The problem is that it is working fine until the html page contains only one parameter with the same name; because the source html has inside like 10's of ffmg and the same end string called cs=nt.
I can not even make regex to count the characters because every time you visit the html page the number of characters are different, sometimes +3 else +10. So the only way is to get this sting from the start of param1 to the end of param2.
This is the string I need to get: 1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012
This is the source html example:
\u0026doc=IcuU5Oy8\u0026pen=V9PXaHoOp1gKD25rgAg\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\u0026cs=nt\u0026token=gHgig8eLY3qsQ0bXa\\u0026doc=IcuU5Oy8\u0026pen=V9PXaHoOp1gKD25rgAg\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\u0026cs=nt\u0026token=gHgig8eLY3qsQ0bXa\\u0026doc=IcuU5Oy8\u0026pen=V9PXaHoOp1gKD25rgAg\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\u0026cs=nt\u0026token=gHgig8eLY3qsQ0bXa\
I have copied 3 times the same just for this purpose because it is very big html source and I doubt I can upload it here.
Thanks for your help.
In your questions, you use (?<=\ffmpg=) where \f will match a form feed character which is not present in the data example. If you meant to use \\f it will match \f which is also not present in the example data.
You could get the match using a capturing group instead of using lookarounds as lookbehinds are not widely supported by all browsers.
If you just want to get a single match, you can omit the /g global flag.
If you use .+ you will match too much as the .+ will match until the end of the string and then backtracks until the first time it can match \\u0026cs=nt
What you could do instead is be specific in what you would allow to match which for the current string is a character class with the following characters [AC0-9%]+
You could broaden the character class with a range to match chars A-Z instead of AC for example and add more chars or ranges as required.
ffmpg=([AC0-9%]+)\\\\u0026cs=nt
Regex demo
For example
const regex = /ffmpg=([AC0-9%]+)\\\\u0026cs=nt/;
const str = `\\\\u0026doc=IcuU5Oy8\\\\u0026pen=V9PXaHoOp1gKD25rgAg\\\\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\\\\u0026cs=nt\\\\u0026token=gHgig8eLY3qsQ0bXa\\\\\\\\u0026doc=IcuU5Oy8\\\\u0026pen=V9PXaHoOp1gKD25rgAg\\\\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\\\\u0026cs=nt\\\\u0026token=gHgig8eLY3qsQ0bXa\\\\\\\\u0026doc=IcuU5Oy8\\\\u0026pen=V9PXaHoOp1gKD25rgAg\\\\u0026ffmpg=1714248%2C23851735%2C23804281%2C23839597%2C23357901%2C3313341%2C3316343%2C23848795%2C3300132%2C26853996%2C3300114%2C3315790%2C23857451%2C23856472%2C23851936%2C3300161%2C3314786%2C23856652%2C23859863%2C23837993%2C23833479%2C23861502%2C23842630%2C23842986%2C23861012\\\\u0026cs=nt\\\\u0026token=gHgig8eLY3qsQ0bXa\\\\`;
console.log(str.match(regex)[1]);
Try this:
(?<=ffmpg=)([A-F0-9%]+)
Explanation
Since your string only consists of url-encoded characters, you can use [A-F0-9%]+character class to capture it. It will stop when next string starts because there will be a backslash.
See online demo here.
I am not really a RegEx expert and hence asking a simple question.
I have a few parameters that I need to use which are in a particular pattern
For example
$$DATA_START_TIME
$$DATA_END_TIME
$$MIN_POID_ID_DLAY
$$MAX_POID_ID_DLAY
$$MIN_POID_ID_RELTM
$$MAX_POID_ID_RELTM
And these will be replaced at runtime in a string with their values (a SQL statement).
For example I have a simple query
select * from asdf where asdf.starttime = $$DATA_START_TIME and asdf.endtime = $$DATA_END_TIME
Now when I try to use the RegEx pattern
\$\$[^\W+]\w+$
I do not get all the matches(I get only a the last match).
I am trying to test my usage here https://regex101.com/r/xR9dG0/2
If someone could correct my mistake, I would really appreciate it.
Thanks!
This will do the job:
\$\$\w+/g
See Demo
Just Some clarifications why your regex is doing what is doing:
\$\$[^\W+]\w+$
Unescaped $ char means end of string, so, your pattern is matching something that must be on the end of the string, that's why its getting only the last match.
This group [^\W+] doesn't really makes sense, groups starting with [^..] means negate the chars inside here, and \W is the negation of words, and + inside the group means literally the char +, so you are saying match everything that is Not a Not word and that is not a + sign, i guess that was not what you wanted.
To match the next word just \w+ will do it. And the global modifier /g ensures that you will not stop on the first match.
This should work - Based on what you said you wanted to match this should work . Also it won't match $$lower_case_strings if that's what you wanted. If not, add the "i" flag also.
\${2}[A-Z_]+/g
In Notepad++ I need to match "dog" (search) in
<tag>old-string/dog.swf">more-old-string</tag>
then use a back-reference (\1) to include it in another string (replace):
new-string_\1>more-new-string
to give the result
new-string_dog.swf">more-new-string
I'm new to regex, so please show me how to do this first by matching "dog", then by excluding all old-string in the result.
Edit: I realize this might be confusing, so I posted the actual problem here: regex find word in string, replace word in new string (using Notepad++). I hope it makes more sense.
I am totally going off a limb here trying to understand what you want, but if I have understood you correctly you want to:
match a certain word in one string
create a new string with data from the old one, under the old string which should be untouched
If so, this regular expression: /^(.*?/([^"]+)\.swf)(".*$)/i with this replacement: \1\3\r\n<test>\2</test> should do the trick. I have used <test></test> to show you where you put your "new-string" stuff.
I hope this helps!
I thought that by default my Regex would exhibit the greedy behavior that I want, but it is not in the following code:
Regex keywords = new Regex(#"in|int|into|internal|interface");
var targets = keywords.ToString().Split('|');
foreach (string t in targets)
{
Match match = keywords.Match(t);
Console.WriteLine("Matched {0,-9} with {1}", t, match.Value);
}
Output:
Matched in with in
Matched int with in
Matched into with in
Matched internal with in
Matched interface with in
Now I realize that I could get it to work for this small example if I simply sorted the keywords by length descending, but
I want to understand why this
isn't working as expected, and
the actual project I am working on
has many more words in the Regex and
it is important to keep them in
alphabetical order.
So my question is: Why is this being lazy and how do I fix it?
Laziness and greediness applies to quantifiers only (?, *, +, {min,max}). Alternations always match in order and try the first possible match.
It looks like you're trying to word break things. To do that you need the entire expression to be correct, your current one is not. Try this one instead..
new Regex(#"\b(in|int|into|internal|interface)\b");
The "\b" says to match word boundaries, and is a zero-width match. This is locale dependent behavior, but in general this means whitespace and punctuation. Being a zero width match it will not contain the character that caused the regex engine to detect the word boundary.
According to RegularExpressions.info, regular expressions are eager. Therefore, when it goes through your piped expression, it stops on the first solid match.
My recommendation would be to store all of your keywords in an array or list, then generate the sorted, piped expression when you need it. You would only have to do this once too as long as your keyword list doesn't change. Just store the generated expression in a singleton of some sort and return that on regex executions.
I suspect this has already been answered somewhere, but I can't find it, so...
I need to extract a string from between two tokens in a larger string, in which the second token will probably appear again meaning... (pseudo code...)
myString = "A=abc;B=def_3%^123+-;C=123;" ;
myB = getInnerString(myString, "B=", ";" ) ;
method getInnerString(inStr, startToken, endToken){
return inStr.replace( EXPRESSION, "$1");
}
so, when I run this using expression ".+B=(.+);.+"
I get "def_3%^123+-;C=123;" presumably because it just looks for the LAST instance of ';' in the string, rather than stopping at the first one it comes to.
I've tried using (?=) in search of that first ';' but it gives me the same result.
I can't seem to find a regExp reference that explains how one can specify the "NEXT" token rather than the one at the end.
any and all help greatly appreciated.
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You're using a greedy pattern by not specifying the ? in it. Try this:
".+B=(.+?);.+"
Try this:
B=([^;]+);
This matches everything between B= and ; unless it is a ;. So it matches everything between B= and the first ; thereafter.
(This is a continuation of the conversation from the comments to Evan's answer.)
Here's what happens when your (corrected) regex is applied: First, the .+ matches the whole string. Then it backtracks, giving up most of the characters it just matched until it gets to the point where the B= can match. Then the (.+?) matches (and captures) everything it sees until the next part, the semicolon, can match. Then the final .+ gobbles up the remaining characters.
All you're really interested in is the "B=" and the ";" and whatever's between them, so why match the rest of the string? The only reason you have to do that is so you can replace the whole string with the contents of the capturing group. But why bother doing that if you can access contents of the group directly? Here's a demonstration (in Java, because I can't tell what language you're using):
String s = "A=abc;B=def_3%^123+-;C=123;";
Pattern p = Pattern.compile("B=(.*?);");
Matcher m = p.matcher(s);
if (m.find())
{
System.out.println(m.group(1));
}
Why do a 'replace' when a 'find' is so much more straightforward? Probably because your API makes it easier; that's why we do it in Java. Java has several regex-oriented convenience methods in its String class: replaceAll(), replaceFirst(), split(), and matches() (which returns true iff the regex matches the whole string), but not find(). And there's no convenience method for accessing capturing groups, either. We can't match the elegance of Perl one-liners like this:
print $1 if 'A=abc;B=def_3%^123+-;C=123;' =~ /B=(.*?);/;
...so we content ourselves with hacks like this:
System.out.println("A=abc;B=def_3%^123+-;C=123;"
.replaceFirst(".+B=(.*?);.+", "$1"));
Just to be clear, I'm not saying not to use these hacks, or that there's anything wrong with Evan's answer--there isn't. I just think we should understand why we use them, and what trade-offs we're making when we do.