I'm trying to find out a way to match the following test string:
token = '1866FB352F4DF76BCB92C3482DB7D7B4F562';
The data I want returned is...
1866FB352F4DF76BCB92C3482DB7D7B4F562
I've tried the following, the closes I have is this, but it's including the single quote at the end:
(?!token = ')(\w+)';
Now, another one, which works closely, but it's including the last single quote:
'([^']+)'
Anyone want to take a stab at this?
Update: After looking at what I need to parse, I found the same value in the html, in the form area, which looks like it might be easier to grab:
name="token" value="482CD1FE037F68D5A36F4C961A6D57D9"
Again, I just need the contents within value="*"
However, the regex will have to parse the entire html source, so I assume I will need to search for name="toke" value= but not include that in the result set.
If your regex engine supports lookaround, you can use
(?<=')\w+(?=')
This matches an alphanumeric word if it's surrounded by single quotes, without making those quotes a part of the actual match. If you only want to match hexadecimal numbers, use
(?i)(?<=')[0-9A-F]+(?=')
EDIT:
Since you have now added that you're using JMeter, and because JMeter doesn't support lookbehind assertions for reasons incomprehensible to me (because Java itself does support it just fine), you can possibly cheat like this:
\b[0-9A-F]+(?=')
only checks whether an entire hex number occurs right before a ' character. It does not check for the presence of an opening quote, but chances are that this won't matter.
Related
I am trying to create a bunch of YAML files, mostly composed of strings of text. Now when using apostrophes in words, they must be escaped by typing a double apostrophe, because I’m using apostrophes to wrap the strings.
I want to create a regex that will check for apostrophes in the text that aren’t double. What I have is this:
^([^'\n]*?)'(([^'\n]*?)'(?!')([^'\n]+?))*?'$\n
https://regex101.com/r/v4nUTn/3
My issue is that as soon as my string has a double apostrophe, but also has an apostrophe which isn’t a double apostrophe, it doesn’t match because my negative lookahead doesn’t match as soon as it sees the double apostrophe. (for example the string t''e'st won’t match even though it is missing a double apostrophe after the e)
How can I make it so that my negative lookahead will not fail as soon as it sees one double apostrophe?
This regex should work:
\w'\w
Test here.
My guess is that maybe an expression similar to
('[^'\r\n]*'|[^\r\n\w']+)|([\w']*)
would be an option to look into.
If the second capturing group returns true, then the string is undesired.
If you wish to explore/simplify/modify the expression, it's been
explained on the top right panel of
regex101.com. If you'd like, you
can also watch in this
link, how it would match
against some sample inputs.
One suggestion would be to do this in two steps.
For example, if every 'candidate' value looks like this: - 'something here' (where you want to test the apostrophes in the something here content of the string, then first isolate out that content via:
/^\s*- '(.+)'$/im
And then make sure all apostrophe's appear as you want them to appear within match group 1 of the result.
Then, replace the original match with your 'sanitised' match.
Doing this means you don't have to be concerned with the bounding apostrophes causing complications to the check for apostrophes in the value.
Note: there may well be a perfect one-step regex to do this, but understanding that you can break tasks into several steps is useful if you spend a lot of time with regular expressions, and can help you sidestep 'perfect regex paralysis'.
If you want your string to match if there is at least one 'single quote' between your singlequote strings, then you should allow consumption of either a string which doesn't have any singlequote in it or consume if it contains two singlequotes and then you should modify your regex a bit to consume two singlequotes and add |'' in your regex, which will now consume either non-singlequote text or a portion which has at least two singlequotes.
Try this updated regex demo and see if this works like you wanted?
https://regex101.com/r/v4nUTn/4
I need some help with building up my regex.
What I am trying to do is match a specific part of text with unpredictable parts in between the fixed words. An example is the sentence one gets when replying to an email:
On date at time person name has written:
The cursive parts are variable, might contains spaces or a new line might start from this point.
To get this, I built up my regex as such: On[\s\S]+?at[\s\S]+?person[\s\S]+?has written:
Basically, the [\s\S]+? is supposed to fill in any letter, number, space or break/new line as I am unable to predict what could be between the fixed words tha I am sure will always be there.
Now comes the hard part, when I would add the word "On" somewhere in the text above the sentence that I want to match, the regex now matches a much bigger text than I want. This is due to the use of [\s\S]+.
How am I able to make my regex match as less characters as possible? Using "?" before the "+" to make it lazy does not help.
Example is here with words "From - This - Point - Everything:". Cases are ignored.
Correct: https://regexr.com/3jdek.
Wrong because of added "From": https://regexr.com/3jdfc
The regex is to be used in VB.NET
A more real life, with html tags, can be found here. Here, I avoided using [\s\S]+? or (.+)?(\r)?(\n)?(.+?)
Correct: https://regexr.com/3jdd1
Wrong: https://regexr.com/3jdfu after adding certain parts of the regex in the text above. Although, in html, barely possible to occur as the user would never write the matching tag himself, I do want to make sure my regex is correctjust in case
These things are certain: I know with what the part of text starts, no matter where in respect to the entire text, I know with what the part of text ends, and there are specific fixed words that might make the regex more reliable, but they can be ommitted. Any text below the searched part is also allowed to be matched, but no text above may be matched at all
Another example where it goes wrong: https://regexr.com/3jdli. Basically, I have less to go with in this text, so the regex has less tokens to work with. Adding just the first < already makes the regex take too much.
From my own experience, most problems are avoided when making sure I do not use any [\s\S]+? before I did a (\r)?(\n)? first
[\s\S] matches all character because of union of two complementary sets, it is like . with special option /s (dot matches newlines). and regex are greedy by default so the largest match will be returned.
Following correct link, the token just after the shortest match must be geschreven, so another way to write without using lazy expansion, which is more flexible is to prepend the repeated chracter set by a negative lookahead inside loop,
so
<blockquote type="cite" [^>]+?>[^O]+?Op[^h]+?heeft(.+?(?=geschreven))geschreven:
becomes
<blockquote type="cite" [^>]+?>[^O]+?Op[^h]+?heeft((?:(?!geschreven).)+)geschreven:
(?: ) is for non capturing the group which just encapsulates the negative lookahead and the . (which can be replaced by [\s\S])
(?! ) inside is the negative lookahead which ensures current position before next character is not the beginning of end token.
Following comments it can be explicitly mentioned what should not appear in repeating sequence :
From(?:(?!this)[\s\S])+this(?:(?!point)[\s\S])+point(?:(?!everything)[\s\S])+everything:
or
From(?:(?!From|this)[\s\S])+this(?:(?!point)[\s\S])+point(?:(?!everything)[\s\S])+everything:
or
From(?:(?!From|this)[\s\S])+this(?:(?!this|point)[\s\S])+point(?:(?!everything)[\s\S])+everything:
to understand what the technic (?:(?!tokens)[\s\S])+ does.
in the first this can't appear between From and this
in the second From or this can't appear between From and this
in the third this or point can't appear between this and point
etc.
I've searched all the other Regex on Google Analytics questions but I can't use the answers as this is pretty specific to my problem.
I want to set a goal but use Regex to flag it as a goal IF string includes
/client-thank-you/ AND anything EXCEPT hire
so in other words
/client-thank-you/hire is not correct
/client-thank-you/anything/else is correct
Each of the following regexes will match any string that contains /client-thank-you/ and does not contain hire, depending on what assumption(s) you make about where "hire" is in the string.
Solution
Where can "hire" be located in the string?
Anywhere:
((?!hire).)*?/client-thank-you/((?!hire).)*
Only following the "/client-thank-you/":
.*?/client-thank-you/((?!hire).)*
Only immediately following the "/client-thank-you/":
.*?/client-thank-you/(?!hire).*
Notes
Optimization:
Each of these regexes will match the entire string. If your tool lets you determine if a string contains a substring match (rather than naively attempting to match the entire string), then you could optimize the second and third regexes by removing the leading .*?. Likewise, the third regex could be further optimized by removing the trailing .* as well.
Positively require "anything":
Note that all of these regexes assume that a string that ends with "/client-thank-you/" (with nothing after it) is valid. If this assumption is incorrect (i.e. the string .*/client-thank-you/$ is not a match), then change the trailing * on every regex to +. This would also mean that you have to keep the last .* on the third regex as a .+ (i.e. don't optimize that away).
EDIT:
The above will not work since GA uses a very limited version of regex (that does not include lookaround). If there is no other GA tool (other than a single regex) that you can use that meets your needs, then you could use the following as a last-ditch effort:
([-._~!$&'()*+,;=:#/0-9A-Za-gi-z]|h[-._~!$&'()*+,;=:#/0-9A-Za-hj-z]|hi[-._~!$&'()*+,;=:#/0-9A-Za-qs-z]|hir[-._~!$&'()*+,;=:#/0-9A-Za-df-z]|.{1,3}$)
And in expanded form for illustration purposes only:
( | | | | )
[-._~!$&'()*+,;=:#/0-9A-Za-gi-z] h[-._~!$&'()*+,;=:#/0-9A-Za-hj-z] hi[-._~!$&'()*+,;=:#/0-9A-Za-qs-z] hir[-._~!$&'()*+,;=:#/0-9A-Za-df-z] .{1,3}$
This regex will match 1-4 characters that do not form "hire". It does so by matching the minimum number of characters necessary to verify that the match is neither "hire" nor can serve as a prefix of "hire". It takes into account end-of-line (e.g. "hir" is valid if there is nothing else after it). The characters that it matches are all valid characters that can occur in the path component of a URL as specified in RFC 3986.
You use this regex by substituting it for every ((?!hire).) in any of the solutions given above. For example:
.*?/client-thank-you/([-._~!$&'()*+,;=:#/0-9A-Za-gi-z]|h[-._~!$&'()*+,;=:#/0-9A-Za-hj-z]|hi[-._~!$&'()*+,;=:#/0-9A-Za-qs-z]|hir[-._~!$&'()*+,;=:#/0-9A-Za-df-z]|.{1,3}$).*
This matches any url that contains "/client-thank-you/" but not "/client-thank-you/hire".
Do be careful, though. Doubled "h"s will make this workaround fail (e.g. "hhire"). However, if "hire" will only ever follow a path delimiter (i.e. /hire/), then that shouldn't be a problem.
If you can't use a lookahead like Travis suggested, then I suggest setting the goal to fire on an event instead of a pageview.
If you're using Google Tag Manager, you'll have the ability to write a more advanced regex, or at least set a blocking rule for the event that prevents it from firing when 'hire' is in the page URL.
I've got a practical application for a vim regex where I'd like to remove numbers from the end of file location links. For example, if the developer is sloppy and just adds files and doesn't reuse file locations, you'll end up with something awful like this:
PATH_TO_MY_FILES>
PATH_TO_MY_FILES1>
...
PATH_TO_MY_FILES22>
PATH_TO_MY_FILES_ELSEWHERE>
PATH_TO_MY_FILES_ELSEWHERE1>
...
So all I want to do is to S&R and replace PATH_TO_MY_FILES*\d+ with PATH_TO_MY_FILES* using regex. Obviously I am not doing it quite right, so I was hoping someone here could not spoon feed the answer necessarily, but throw a regex buzzword my way to get me on track.
Here's what I have tried:
:%s\(PATH_TO_MY_FILES\w*\)\(\d+\)>:gc
But this doesn't work, i.e. if I just do a vim search on that, it doesn't find anything. However, if I use this:
:%s\(PATH_TO_MY_FILES\w*\)\(\d\)>:gc
It will match the string, but the grouping is off, as expected. For example, the string PATH_TO_MY_FILES22 will be grouped as (PATH_TO_MY_FILES2)(2), presumably because the \d only matches the 2, and the \w match includes the first 2.
Question 1: Why doesn't \d+ work?
If I go ahead and use the second string (which is wrong), Vim appears to find a match (even though the grouping is wrong), but then does the replacement incorrectly.
For example, given that we know the \d will only match the last number in the string, I would expect PATH_TO_MY_FILES22> to get replaced with PATH_TO_MY_FILES2>. However, instead it replaces it with this:
PATH_TO_MY_FILES2PATH_TO_MY_FILES22>gt
So basically, it looks like it finds PATH_TO_MY_FILES22>, but then replaces only the & with group 1, which is PATH_TO_MY_FILES2.
I tried another regex at Regexr.com to see how it would interpret my grouping, and it looked correct, but maybe a hack around my lack of regex understanding:
(PATH_TO_\D*)(\d*)>
This correctly broke my target string into the PATH part and the entire number, so I was happy. But then when I used this in Vim, it found the match, but still replaced only the &.
Question 2: Why is Vim only replacing the &?
Answer 1:
You need to escape the + or it will be taken literally. For example \d\+ works correctly.
Answer 2:
An unescaped & in the replacement portion of a substitution means "the entire matched text". You need to escape it if you want a literal ampersand.
I have an text that consists of information enclosed by a certain pattern.
The only thing I know is the pattern: "${template.start}" and ${template.end}
To keep it simple I will substitute ${template.start} and ${template.end} with "a" in the example.
So one entry in the text would be:
aINFORMATIONHEREa
I do not know how many of these entries are concatenated in the text. So the following is correct too:
aFOOOOOOaaASDADaaASDSDADa
I want to write a regular expression to extract the information enclosed by the "a"s.
My first attempt was to do:
a(.*)a
which works as long as there is only one entry in the text. As soon as there are more than one entries it failes, because of the .* matching everything. So using a(.*)a on aFOOOOOOaaASDADaaASDSDADa results in only one capturing group containing everything between the first and the last character of the text which are "a":
FOOOOOOaaASDADaaASDSDAD
What I want to get is something like
captureGroup(0): aFOOOOOOaaASDADaaASDSDADa
captureGroup(1): FOOOOOO
captureGroup(2): ASDAD
captureGroup(3): ASDSDAD
It would be great to being able to extract each entry out of the text and from each entry the information that is enclosed between the "a"s. By the way I am using the QRegExp class of Qt4.
Any hints? Thanks!
Markus
Multiple variation of this question have been seen before. Various related discussions:
Regex to replace all \n in a String, but no those inside [code] [/code] tag
Using regular expressions how do I find a pattern surrounded by two other patterns without including the surrounding strings?
Use RegExp to match a parenthetical number then increment it
Regex for splitting a string using space when not surrounded by single or double quotes
What regex will match text excluding what lies within HTML tags?
and probably others...
Simply use non-greedy expressions, namely:
a(.*?)a
You need to match something like:
a[^a]*a
You have a couple of working answers already, but I'll add a little gratuitous advice:
Using regular expressions for parsing is a road fraught with danger
Edit: To be less cryptic: for all there power, flexibility and elegance, regular expression are not sufficiently expressive to describe any but the simplest grammars. Ther are adequate for the problem asked here, but are not a suitable replacement for state machine or recursive decent parsers if the input language become more complicated.
SO, choosing to use RE for parsing input streams is a decision that should be made with care and with an eye towards the future.