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.
Related
I want to select some string combination (with dots(.)) from a very long string (sql). The full string could be a single line or multiple line with new line separator, and this combination could be in start (at first line) or a next line (new line) or at both place.
I need help in writing a regex for it.
Examples:
String s = I am testing something like test.test.test in sentence.
Expected output: test.test.test
Example2 (real usecase):
UPDATE test.table
SET access = 01
WHERE access IN (
SELECT name FROM project.dataset.tablename WHERE name = 'test' GROUP BY 1 )
Expected output: test.table and project.dataset.tablename
, can I also add some prefix or suffix words or space which should be present where ever this logic gets checked. In above case if its update regex should pick test.table, but if the statement is like select test.table regex should not pick it up this combinations and same applies for suffix.
Example3: This is to illustrate the above theory.
INS INTO test.table
SEL 'abcscsc', wu_id.Item_Nbr ,1
FROM test.table as_t
WHERE as_t.old <> 0 AND as_t.date = 11
AND (as_t.numb IN ('11') )
Expected Output: test.table, test.table (Key words are INTO and FROM)
Things Not Needed in selection:as_t.numb, as_t.old, as_t.date
If I get the regex I can use in program to extract this word.
Note: Before and after string words to the combination could be anything like update, select { or(, so we have to find the occurrence of words which are joined together with .(dot) and all the number of such occurrence.
I tried something like this:
(?<=.)(.?)(?=.)(.?) -: This only selected the word between two .dot and not all.
.(?<=.)(.?)(?=.)(.?). - This everything before and after.
To solve your initial problem, we can just use some negation. Here's the pattern I came up with:
[^\s]+\.[^\s]+
[^ ... ] Means to make a character class including everything except for what's between the brackets. In this case, I put \s in there, which matches any whitespace. So [^\s] matches anything that isn't whitespace.
+ Is a quantifier. It means to find as many of the preceding construct as you can without breaking the match. This would happily match everything that's not whitespace, but I follow it with a \., which matches a literal .. The \ is necessary because . means to match any character in regex, so we need to escape it so it only has its literal meaning. This means there has to be a . in this group of non-whitespace characters.
I end the pattern with another [^\s]+, which matches everything after the . until the next whitespace.
Now, to solve your secondary problem, you want to make this match only work if it is preceded by a given keyword. Luckily, regex has a construct almost specifically for this case. It's called a lookbehind. The syntax is (?<= ... ) where the ... is the pattern you want to look for. Using your example, this will only match after the keywords INTO and FROM:
(?<=(?:INTO|FROM)\s)[^\s]+\.[^\s]+
Here (?:INTO|FROM) means to match either the text INTO or the text FROM. I then specify that it should be followed by a whitespace character with \s. One possible problem here is that it will only match if the keywords are written in all upper case. You can change this behavior by specifying the case insensitive flag i to your regex parser. If your regex parser doesn't have a way to specify flags, you can usually still specify it inline by putting (?i) in front of the pattern, like so:
(?i)(?<=(?:INTO|FROM)\s)[^\s]+\.[^\s]+
If you are new to regex, I highly recommend using the www.regex101.com website to generate regex and learn how it works. Don't forget to check out the code generator part for getting the regex code based on the programming language you are using, that's a cool feature.
For your question, you need a regex that understands any word character \w that matches between 0 and unlimited times, followed by a dot, followed by another series of word character that repeats between 0 and unlimited times.
So here is my solution to your question:
Your regex in JavaScript:
const regex = /([\w][.][\w])+/gm;
in Java:
final String regex = "([\w][.][\w])+";
in Python:
regex = r"([\w][.][\w])+"
in PHP:
$re = '/([\w][.][\w])+/m';
Note that: this solution is written for your use case (to be used for SQL strings), because now if you have something like '.word' or 'word..word', it will still catch it which I assume you don't have a string like that.
See this screenshot for more details
I'm trying to make a Regex that matches this string {Date HH:MM:ss}, but here's the trick: HH, MM and ss are optional, but it needs to be "HH", not just "H" (the same thing applies to MM and ss). If a single "H" shows up, the string shouldn't be matched.
I know I can use H{2} to match HH, but I can't seem to use that functionality plus the ? to match zero or one time (zero because it's optional, and one time max).
So far I'm doing this (which is obviously not working):
Regex dateRegex = new Regex(#"\{Date H{2}?:M{2}?:s{2}?\}");
Next question. Now that I have the match on the first string, I want to take only the HH:MM:ss part and put it in another string (that will be the format for a TimeStamp object).
I used the same approach, like this:
Regex dateFormatRegex = new Regex(#"(HH)?:?(MM)?:?(ss)?");
But when I try that on "{Date HH:MM}" I don't get any matches. Why?
If I add a space like this Regex dateFormatRegex = new Regex(#" (HH)?:?(MM)?:?(ss)?");, I have the result, but I don't want the space...
I thought that the first parenthesis needed to be escaped, but \( won't work in this case. I guess because it's not a parenthesis that is part of the string to match, but a key-character.
(H{2})? matches zero or two H characters.
However, in your case, writing it twice would be more readable:
Regex dateRegex = new Regex(#"\{Date (HH)?:(MM)?:(ss)?\}");
Besides that, make sure there are no functions available for whatever you are trying to do. Parsing dates is pretty common and most programming languages have functions in their standard library - I'd almost bet 1k of my reputation that .NET has such functions, too.
In your edit you mention an unwanted leading space in the result… to check a leading or trailing condition together with your regex without including this to the result you can use lookaround feature of regex.
new Regex(#"(?<=Date )(HH)?:?(MM)?:?(ss)?")
(?<=...) is a lookbehind pattern.
Regex test site with this example.
For input Date HH:MM:ss, it will match both regexes (with or without lookbehind).
But input FooBar HH:MM:ss will still match a simple regex, but the lookbehind will fail here. Lookaround doesn't change the content of the result, but it prevents false matches (e.g., this second input that is not a Date).
Find more information on regex and lookaround here.
I am trying to write a regex that matches only strings like this:
89-72
10-123
109-12
122-311(a)
22-311(a)(1)(d)(4)
These strings are embedded in sentences and sometimes there are 2 potential matches in the sentence like this:
In section 10-123 which references section 122-311(a) there is a phone number 456-234-2222
I do not want to match the phone. Here is my current working regex
\d{2,3}\-\d{2,3}(\([a-zA-Z0-9]\))*
see DEMO
I've been looking on Stack and have not found anything yet. Any help would be appreciated. Will be using this in a google sheet and potentially postgres.
Based on regex, suggested by #Wiktor Stribiżew:
=REGEXEXTRACT(A1,REPT("\b(\d{2,3}-\d{2,3}\b(?:\([A-Za-z0-9]\))*)(?:[^-]|$)(?:.*)",LEN(REGEXREPLACE(REGEXREPLACE(A1,"\b(\d{2,3}-\d{2,3}\b(?:\([A-Za-z0-9]\))*)(?:[^-]|$)", char (9)),"[^"&char(9)&"]",""))))
The formula will return all matches.
String:
A
In 22-311(a)(1)(d)(4) section 10-123 which ... 122-311(a) ... number 456-234-2222
Output:
B C D
22-311(a)(1)(d)(4) 10-123 122-311(a)
Solution
To extract all matches from a string, use this pattern:
=REGEXEXTRACT(A1,
REPT(basic_regex & "(?:.*)",
LEN(REGEXREPLACE(REGEXREPLACE(A1,basic_regex, char (9)),"[^"&char(9)&"]",""))))
The tail of a function:
LEN(REGEXREPLACE(REGEXREPLACE(A1,basic_regex, char (9)),"[^"&char(9)&"]","")))
is just for finding number 3 -- how many entries of a pattern in a string.
To not match the phone number you have to indicate that the match must neither be preceded nor followed by \d or -. Google spreadsheet uses RE2 which does not support look around assertion (see the list of supported feature) so as far as I can tell, the only solution is to add a character before and after the match, or the string boundary:
(?:^|[^-\d])\d{2,3}\-\d{2,3}(\([a-zA-Z0-9]\))*(?:$|[^-\d])
(?:^|[^-\d]) means either the start of a line (^) or a character that is not - or \d (you might want to change that, and forbid all letters as well). $ is the end of a line. ^ and $ only do what you want with the /m flag though
As you can see here this finds the correct strings, but with additional spaces around some of the matches.
I am working with government measures and am required to parse a string that contains variable information based on delimiters that come from issuing bodies associated with the fda.
I am trying to retrieve the delimiter and the value after the delimiter. I have searched for hours to find a regex solution to retrieve both the delimiter and the value that follows it and, though there seems to be posts that handle this, the code found in the post haven't worked.
One of the major issues in this task is that the delimiters often have repeated characters. For instance: delimiters are used such as "=", "=,", "/=". In this case I would need to tell the difference between "=" and "=,".
Is there a regex that would handle all of this?
Here is an example of the string :
=/A9999XYZ=>100T0479&,1Blah
Notice the delimiters are:
"=/"
"=>'
"&,1"
Any help would be appreciated.
You can use a regex like this
(=/|=>|&,1)|(\w+)
Working demo
The idea is that the first group contains the delimiters and the 2nd group the content. I assume the content can be word characters (a to z and digits with underscore). You have then to grab the content of every capturing group.
You need to capture both the delimiter and the value as group 1 and 2 respectively.
If your values are all alphanumeric, use this:
(&,1|\W+)(\w+)
See live demo.
If your values can contain non-alphanumeric characters, it get complicated:
(=/|=>|=,|=|&,1)((?:.(?!=/|=>|=,|=|&,1))+.)
See live demo.
Code the delimiters longest first, eg "=," before "=", otherwise the alternation, which matches left to right, will match "=" and the comma will become part of the value.
This uses a negative look ahead to stop matching past the next delimiter.
Is there a simple way to ignore the white space in a target string when searching for matches using a regular expression pattern? For example, if my search is for "cats", I would want "c ats" or "ca ts" to match. I can't strip out the whitespace beforehand because I need to find the begin and end index of the match (including any whitespace) in order to highlight that match and any whitespace needs to be there for formatting purposes.
You can stick optional whitespace characters \s* in between every other character in your regex. Although granted, it will get a bit lengthy.
/cats/ -> /c\s*a\s*t\s*s/
While the accepted answer is technically correct, a more practical approach, if possible, is to just strip whitespace out of both the regular expression and the search string.
If you want to search for "my cats", instead of:
myString.match(/m\s*y\s*c\s*a\*st\s*s\s*/g)
Just do:
myString.replace(/\s*/g,"").match(/mycats/g)
Warning: You can't automate this on the regular expression by just replacing all spaces with empty strings because they may occur in a negation or otherwise make your regular expression invalid.
Addressing Steven's comment to Sam Dufel's answer
Thanks, sounds like that's the way to go. But I just realized that I only want the optional whitespace characters if they follow a newline. So for example, "c\n ats" or "ca\n ts" should match. But wouldn't want "c ats" to match if there is no newline. Any ideas on how that might be done?
This should do the trick:
/c(?:\n\s*)?a(?:\n\s*)?t(?:\n\s*)?s/
See this page for all the different variations of 'cats' that this matches.
You can also solve this using conditionals, but they are not supported in the javascript flavor of regex.
You could put \s* inbetween every character in your search string so if you were looking for cat you would use c\s*a\s*t\s*s\s*s
It's long but you could build the string dynamically of course.
You can see it working here: http://www.rubular.com/r/zzWwvppSpE
If you only want to allow spaces, then
\bc *a *t *s\b
should do it. To also allow tabs, use
\bc[ \t]*a[ \t]*t[ \t]*s\b
Remove the \b anchors if you also want to find cats within words like bobcats or catsup.
This approach can be used to automate this
(the following exemplary solution is in python, although obviously it can be ported to any language):
you can strip the whitespace beforehand AND save the positions of non-whitespace characters so you can use them later to find out the matched string boundary positions in the original string like the following:
def regex_search_ignore_space(regex, string):
no_spaces = ''
char_positions = []
for pos, char in enumerate(string):
if re.match(r'\S', char): # upper \S matches non-whitespace chars
no_spaces += char
char_positions.append(pos)
match = re.search(regex, no_spaces)
if not match:
return match
# match.start() and match.end() are indices of start and end
# of the found string in the spaceless string
# (as we have searched in it).
start = char_positions[match.start()] # in the original string
end = char_positions[match.end()] # in the original string
matched_string = string[start:end] # see
# the match WITH spaces is returned.
return matched_string
with_spaces = 'a li on and a cat'
print(regex_search_ignore_space('lion', with_spaces))
# prints 'li on'
If you want to go further you can construct the match object and return it instead, so the use of this helper will be more handy.
And the performance of this function can of course also be optimized, this example is just to show the path to a solution.
The accepted answer will not work if and when you are passing a dynamic value (such as "current value" in an array loop) as the regex test value. You would not be able to input the optional white spaces without getting some really ugly regex.
Konrad Hoffner's solution is therefore better in such cases as it will strip both the regest and test string of whitespace. The test will be conducted as though both have no whitespace.