I can't seem to make this regex work.
The input is as follows. Its really on one row but I have inserted line breaks after each \r\n so that it's easier to see, so no check for space characters are needed.
01-03\r\n
01-04\r\n
TEXTONE\r\n
STOCKHOLM\r\n
350,00\r\n ---- 350,00 should be the last value in the first match
12-29\r\n
01-03\r\n
TEXTTWO\r\n
COPENHAGEN\r\n
10,80\r\n
This could go on with another 01-31 and 02-01, marking another new match (these are dates).
I would like to have a total of 2 matches for this input.
My problem is that I cant figure out how to look ahead and match the starting of a new match (two following dates) but not to include those dates within the first match. They should belong to the second match.
It's hard to explain, but I hope someone will get me.
This is what I got so far but its not even close:
(.*?)((?<=\\d{2}-\\d{2}))
The matches I want are:
1: 01-03\r\n01-04\r\nTEXTONE\r\nSTOCKHOLM\r\n350,00\r\n
2: 12-29\r\n01-03\r\nTEXTTWO\r\nCOPENHAGEN\r\n10,80\r\n
After that I can easily separate the columns with \r\n.
Can this more explicit pattern work to you?
(\d{2}-\d{2})\r\n(\d{2}-\d{2})\r\n(.*)\r\n(.*)\r\n(\d+(?:,?\d+))
Here's another option for you to try:
(.+?)(?=\d{2}-\d{2}\\r\\n\d{2}-\d{2}|$)
Rubular
/
\G
(
(?:
[0-9]{2}-[0-9]{2}\r\n
){2}
(?:
(?! [0-9]{2}-[0-9]{2}\r\n ) [^\n]*\n
)*
)
/xg
Why do so much work?
$string = q(01-03\r\n01-04\r\nTEXTONE\r\nSTOCKHOLM\r\n350,00\r\n12-29\r\n01-03\r\nTEXTTWO\r\nCOPENHAGEN\r\n10,80\r\n);
for (split /(?=(?:\d{2}-\d{2}\\r\\n){2})/, $string) {
print join( "\t", split /\\r\\n/), "\n"
}
Output:
01-03 01-04 TEXTONE STOCKHOLM 350,00
12-29 01-03 TEXTTWO COPENHAGEN 10,80`
Related
I'm going nuts trying to get a regex to detect spam of keywords in the user inputs. Usually there is some normal text at the start and the keyword spam at the end, separated by commas or other chars.
What I need is a regex to count the number of keywords to flag the text for a human to check it.
The text is usually like this:
[random text, with commas, dots and all]
keyword1, keyword2, keyword3, keyword4, keyword5,
Keyword6, keyword7, keyword8...
I've tried several regex to count the matches:
-This only gets one out of two keywords
[,-](\w|\s)+[,-]
-This also matches the random text
(?:([^,-]*)(?:[^,-]|$))
Can anyone tell me a regex to do this? Or should I take a different approach?
Thanks!
Pr your answer to my question, here is a regexp to match a string that occurs between two commas.
(?<=,)[^,]+(?=,)
This regexp does not match, and hence do not consume, the delimiting commas.
This regexp would match " and hence do not consume" in the previous sentence.
The fact that your regexp matched and consumed the commas was the reason why your attempted regexp only matched every other candidate.
Also if the whole input is a single string you will want to prevent linebreaks. In that case you will want to use;
(?<=,)[^,\n]+(?=,)
http://www.phpliveregex.com/p/1DJ
As others have said this is potentially a very tricky thing to do... It suffers from all of the same failures as general "word filtering" (e.g. people will "mask" the input). It is made even more difficult without plenty of example posts to test against...
Solution
Anyway, assuming that keywords will be on separate lines to the rest of the input and separated by commas you can match the lines with keywords in like:
Regex
#(?:^)((?:(?:[\w\.]+)(?:, ?|$))+)#m
Input
Taken from your question above:
[random text, with commas, dots and all]
keyword1, keyword2, keyword3, keyword4, keyword5,
Keyword6, keyword7, keyword8
Output
// preg_match_all('#(?:^)((?:(?:[\w]+)(?:, ?|$))+)#m', $string, $matches);
// var_dump($matches);
array(2) {
[0]=>
array(2) {
[0]=>
string(49) "keyword1, keyword2, keyword3, keyword4, keyword5,"
[1]=>
string(31) "Keyword6, keyword7, keyword8..."
}
[1]=>
array(2) {
[0]=>
string(49) "keyword1, keyword2, keyword3, keyword4, keyword5,"
[1]=>
string(31) "Keyword6, keyword7, keyword8"
}
}
Explanation
#(?:^)((?:(?:[\w]+)(?:, ?|$))+)#m
# => Starting delimiter
(?:^) => Matches start of line in a non-capturing group (you could just use ^ I was using |\n originally and didn't update)
( => Start a capturing group
(?: => Start a non-capturing group
(?:[\w]+) => A non-capturing group to match one or more word characters a-zA-Z0-9_ (Using a character class so that you can add to it if you need to....)
(?:, ?|$) => A non-capturing group to match either a comma (with an optional space) or the end of the string/line
)+ => End the non-capturing group (4) and repeat 5/6 to find multiple matches in the line
) => Close the capture group 3
# => Ending delimiter
m => Multi-line modifier
Follow up from number 2:
#^((?:(?:[\w]+)(?:, ?|$))+)#m
Counting keywords
Having now returned an array of lines only containing key words you can count the number of commas and thus get the number of keywords
$key_words = implode(', ', $matches[1]); // Join lines returned by preg_match_all
echo substr_count($key_words, ','); // 8
N.B. In most circumstances this will return NUMBER_OF_KEY_WORDS - 1 (i.e. in your case 7); it returns 8 because you have a comma at the end of your first line of key words.
Links
http://php.net/manual/en/reference.pcre.pattern.modifiers.php
http://www.regular-expressions.info/
http://php.net/substr_count
Why not just use explode and trim?
$keywords = array_map ('trim', explode (',', $keywordstring));
Then do a count() on $keywords.
If you think keywords with spaces in are spam, then you can iterate of the $keywords array and look for any that contain whitespace. There might be legitimate reasons for having spaces in a keyword though. If you're talking about superheroes on your system, for example, someone might enter The Tick or Iron Man as a keyword
I don't think counting keywords and looking for spaces in keywords are really very good strategies for detecting spam though. You might want to look into other bot protection strategies instead, or even use manual moderation.
How to match on the String of text between the commas?
This SO Post was marked as a duplicate to my posted question however since it is NOT a duplicate and there were no answers in THIS SO Post that answered my question on how to also match on the strings between the commas see below on how to take this a step further.
How to Match on single digit values in a CSV String
For example if the task is to search the string within the commas for a single 7, 8 or a single 9 but not match on combinations such as 17 or 77 or 78 but only the single 7s, 8s, or 9s see below...
The answer is to Use look arounds and place your search pattern within the look arounds:
(?<=^|,)[789](?=,|$)
See live demo.
The above Pattern is more concise however I've pasted below the Two Patterns provided as solutions to THIS this question of matching on Strings within the commas and they are:
(?<=^|,)[789](?=,|$) Provided by #Bohemian and chosen as the Correct Answer
(?:(?<=^)|(?<=,))[789](?:(?=,)|(?=$)) Provided in comments by #Ouroborus
Demo: https://regex101.com/r/fd5GnD/1
Your first regexp doesn't need a preceding comma
[\w\s]+[,-]
A regex that will match strings between two commas or start or end of string is
(?<=,|^)[^,]*(?=,|$)
Or, a bit more efficient:
(?<![^,])[^,]*(?![^,])
See the regex demo #1 and demo #2.
Details:
(?<=,|^) / (?<![^,]) - start of string or a position immediately preceded with a comma
[^,]* - zero or more chars other than a comma
(?=,|$) / (?![^,]) - end of string or a position immediately followed with a comma
If people still search for this in 2021
([^,\n])+
Match anything except new line and comma
regexr.com/60eme
I think the difficulty is that the random text can also contain commas.
If the keywords are all on one line and it is the last line of the text as a whole, trim the whole text removing new line characters from the end. Then take the text from the last new line character to the end. This should be your string containing the keywords. Once you have this part singled out, you can explode the string on comma and count the parts.
<?php
$string = " some gibberish, some more gibberish, and random text
keyword1, keyword2, keyword3
";
$lastEOL = strrpos(trim($string), PHP_EOL);
$keywordLine = substr($string, $lastEOL);
$keywords = explode(',', $keywordLine);
echo "Number of keywords: " . count($keywords);
I know it is not a regex, but I hope it helps nevertheless.
The only way to find a solution, is to find something that separates the random text and the keywords that is not present in the keywords. If a new line is present in the keywords, you can not use it. But are 2 consecutive new lines? Or any other characters.
$string = " some gibberish, some more gibberish, and random text
keyword1, keyword2, keyword3,
keyword4, keyword5, keyword6,
keyword7, keyword8, keyword9
";
$lastEOL = strrpos(trim($string), PHP_EOL . PHP_EOL); // 2 end of lines after random text
$keywordLine = substr($string, $lastEOL);
$keywords = explode(',', $keywordLine);
echo "Number of keywords: " . count($keywords);
(edit: added example for more new lines - long shot)
I am trying to split texts into "steps"
Lets say my text is
my $steps = "1.Do this. 2.Then do that. 3.And then maybe that. 4.Complete!"
I'd like the output to be:
"1.Do this."
"2.Then do that."
"3.And then maybe that."
"4.Complete!"
I'm not really that good with regex so help would be great!
I've tried many combination like:
split /(\s\d.)/
But it splits the numbering away from text
I would indeed use split. But you need to exclude the digit from the match by using a lookahead.
my #steps = split /\s+(?=\d+\.)/, $steps;
All step-descriptions start with a number followed by a period and then have non-numbers, until the next number. So capture all such patterns
my #s = $steps =~ / [0-9]+\. [^0-9]+ /xg;
say for #s;
This works only if there are surely no numbers in the steps' description, like any approach relying on matching a number (even if followed by a period, for decimal numbers)†
If there may be numbers in there, we'd need to know more about the structure of the text.
Another delimiting pattern to consider is punctuation that ends a sentence (. and ! in these examples), if there are no such characters in steps' description and there are no multiple sentences
my #s = $steps =~ / [0-9]+\. .*? [.!] /xg;
Augment the list of patterns that end an item's description as needed, say with a ?, and/or ." sequence as punctuation often goes inside quotes.‡
If an item can have multiple sentences, or use end-of-sentence punctuation mid-sentence (as a part of a quotation perhaps) then tighten the condition for an item's end by combining footnotes -- end-of-sentence punctuation and followed by number+period
my #s = $steps =~ /[0-9]+\. .*? (?: \."|\!"|[.\!]) (?=\s+[0-9]+\. | \z)/xg;
If this isn't good enough either then we'd really need a more precise description of that text.
† An approach using a "numbers-period" pattern to delimit item's description, like
/ [0-9]+\. .*? (?=\s+[0-9]+\. | \z) /xg;
(or in a lookahead in split) fails with text like
1. Only $2.50 or 1. Version 2.4.1 ...
‡ To include text like 1. Do "this." and 2. Or "that!" we'd want
/ [0-9]+\. .*? (?: \." | !" | [.!?]) /xg;
Following sample code demonstrates power of regex to fill up %steps hash in one line of code.
Once the data obtained you can dice and slice it anyway your heart desires.
Inspect the sample for compliance with your problem.
use strict;
use warnings;
use feature 'say';
use Data::Dumper;
my($str,%steps,$re);
$str = '1.Do this. 2.Then do that. 3.And then maybe that. 4.Complete!';
$re = qr/(\d+)\.(\D+)\./;
%steps = $str =~ /$re/g;
say Dumper(\%steps);
say "$_. $steps{$_}" for sort keys %steps;
Output
$VAR1 = {
'1' => 'Do this',
'2' => 'Then do that',
'3' => 'And then maybe that'
};
1. Do this
2. Then do that
3. And then maybe that
I'm trying to learn something about regular expressions.
Here is what I'm going to match:
/parent/child
/parent/child?
/parent/child?firstparam=abc123
/parent/child?secondparam=def456
/parent/child?firstparam=abc123&secondparam=def456
/parent/child?secondparam=def456&firstparam=abc123
/parent/child?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child?thirdparam=ghi789
/parent/child/
/parent/child/?
/parent/child/?firstparam=abc123
/parent/child/?secondparam=def456
/parent/child/?firstparam=abc123&secondparam=def456
/parent/child/?secondparam=def456&firstparam=abc123
/parent/child/?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child/?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child/?thirdparam=ghi789
My expression should "grabs" abc123 and def456.
And now just an example about what I'm not going to match ("question mark" is missing):
/parent/child/firstparam=abc123&secondparam=def456
Well, I built the following expression:
^(?:/parent/child){1}(?:^(?:/\?|\?)+(?:firstparam=([^&]*)|secondparam=([^&]*)|[^&]*)?)?
But that doesn't work.
Could you help me to understand what I'm doing wrong?
Thanks in advance.
UPDATE 1
Ok, I made other tests.
I'm trying to fix the previous version with something like this:
/parent/child(?:(?:\?|/\?)+(?:firstparam=([^&]*)|secondparam=([^&]*)|[^&]*)?)?$
Let me explain my idea:
Must start with /parent/child:
/parent/child
Following group is optional
(?: ... )?
The previous optional group must starts with ? or /?
(?:\?|/\?)+
Optional parameters (I grab values if specified parameters are part of querystring)
(?:firstparam=([^&]*)|secondparam=([^&]*)|[^&]*)?
End of line
$
Any advice?
UPDATE 2
My solution must be based just on regular expressions.
Just for example, I previously wrote the following one:
/parent/child(?:[?&/]*(?:firstparam=([^&]*)|secondparam=([^&]*)|[^&]*))*$
And that works pretty nice.
But it matches the following input too:
/parent/child/firstparam=abc123&secondparam=def456
How could I modify the expression in order to not match the previous string?
You didn't specify a language so I'll just usre Perl. So basically instead of matching everything, I just matched exactly what I thought you needed. Correct me if I am wrong please.
while ($subject =~ m/(?<==)\w+?(?=&|\W|$)/g) {
# matched text = $&
}
(?<= # Assert that the regex below can be matched, with the match ending at this position (positive lookbehind)
= # Match the character “=” literally
)
\\w # Match a single character that is a “word character” (letters, digits, and underscores)
+? # Between one and unlimited times, as few times as possible, expanding as needed (lazy)
(?= # Assert that the regex below can be matched, starting at this position (positive lookahead)
# Match either the regular expression below (attempting the next alternative only if this one fails)
& # Match the character “&” literally
| # Or match regular expression number 2 below (attempting the next alternative only if this one fails)
\\W # Match a single character that is a “non-word character”
| # Or match regular expression number 3 below (the entire group fails if this one fails to match)
\$ # Assert position at the end of the string (or before the line break at the end of the string, if any)
)
Output:
This regex will work as long as you know what your parameter names are going to be and you're sure that they won't change.
\/parent\/child\/?\?(?:(?:firstparam|secondparam|thirdparam)\=([\w]+)&?)(?:(?:firstparam|secondparam|thirdparam)\=([\w]+)&?)?(?:(?:firstparam|secondparam|thirdparam)\=([\w]+)&?)?
Whilst regex is not the best solution for this (the above code examples will be far more efficient, as string functions are way faster than regexes) this will work if you need a regex solution with up to 3 parameters. Out of interest, why must the solution use only regex?
In any case, this regex will match the following strings:
/parent/child?firstparam=abc123
/parent/child?secondparam=def456
/parent/child?firstparam=abc123&secondparam=def456
/parent/child?secondparam=def456&firstparam=abc123
/parent/child?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child?thirdparam=ghi789
/parent/child/?firstparam=abc123
/parent/child/?secondparam=def456
/parent/child/?firstparam=abc123&secondparam=def456
/parent/child/?secondparam=def456&firstparam=abc123
/parent/child/?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child/?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child/?thirdparam=ghi789
It will now only match those containing query string parameters, and put them into capture groups for you.
What language are you using to process your matches?
If you are using preg_match with PHP, you can get the whole match as well as capture groups in an array with
preg_match($regex, $string, $matches);
Then you can access the whole match with $matches[0] and the rest with $matches[1], $matches[2], etc.
If you want to add additional parameters you'll also need to add them in the regex too, and add additional parts to get your data. For example, if you had
/parent/child/?secondparam=def456&firstparam=abc123&fourthparam=jkl01112&thirdparam=ghi789
The regex will become
\/parent\/child\/?\?(?:(?:firstparam|secondparam|thirdparam|fourthparam)\=([\w]+)&?)(?:(?:firstparam|secondparam|thirdparam|fourthparam)\=([\w]+)&?)?(?:(?:firstparam|secondparam|thirdparam|fourthparam)\=([\w]+)&?)?(?:(?:firstparam|secondparam|thirdparam|fourthparam)\=([\w]+)&?)?
This will become a bit more tedious to maintain as you add more parameters, though.
You can optionally include ^ $ at the start and end if the multi-line flag is enabled. If you also need to match the whole lines without query strings, wrap this whole regex in a non-capture group (including ^ $) and add
|(?:^\/parent\/child\/?\??$)
to the end.
You're not escaping the /s in your regex for starters and using {1} for a single repetition of something is unnecessary; you only use those when you want more than one repetition or a range of repetitions.
And part of what you're trying to do is simply not a good use of a regex. I'll show you an easier way to deal with that: you want to use something like split and put the information into a hash that you can check the contents of later. Because you didn't specify a language, I'm just going to use Perl for my example, but every language I know with regexes also has easy access to hashes and something like split, so this should be easy enough to port:
# I picked an example to show how this works.
my $route = '/parent/child/?first=123&second=345&third=678';
my %params; # I'm going to put those URL parameters in this hash.
# Perl has a way to let me avoid escaping the /s, but I wanted an example that
# works in other languages too.
if ($route =~ m/\/parent\/child\/\?(.*)/) { # Use the regex for this part
print "Matched route.\n";
# But NOT for this part.
my $query = $1; # $1 is a Perl thing. It contains what (.*) matched above.
my #items = split '&', $query; # Each item is something like param=123
foreach my $item (#items) {
my ($param, $value) = split '=', $item;
$params{$param} = $value; # Put the parameters in a hash for easy access.
print "$param set to $value \n";
}
}
# Now you can check the parameter values and do whatever you need to with them.
# And you can add new parameters whenever you want, etc.
if ($params{'first'} eq '123') {
# Do whatever
}
My solution:
/(?:\w+/)*(?:(?:\w+)?\?(?:\w+=\w+(?:&\w+=\w+)*)?|\w+|)
Explain:
/(?:\w+/)* match /parent/child/ or /parent/
(?:\w+)?\?(?:\w+=\w+(?:&\w+=\w+)*)? match child?firstparam=abc123 or ?firstparam=abc123 or ?
\w+ match text like child
..|) match nothing(empty)
If you need only query string, pattern would reduce such as:
/(?:\w+/)*(?:\w+)?\?(\w+=\w+(?:&\w+=\w+)*)
If you want to get every parameter from query string, this is a Ruby sample:
re = /\/(?:\w+\/)*(?:\w+)?\?(\w+=\w+(?:&\w+=\w+)*)/
s = '/parent/child?secondparam=def456&firstparam=abc123&thirdparam=ghi789'
if m = s.match(re)
query_str = m[1] # now, you can 100% trust this string
query_str.scan(/(\w+)=(\w+)/) do |param,value| #grab parameter
printf("%s, %s\n", param, value)
end
end
output
secondparam, def456
firstparam, abc123
thirdparam, ghi789
This script will help you.
First, i check, is there any symbol like ?.
Then, i kill first part of line (left from ?).
Next, i split line by &, where each value splitted by =.
my $r = q"/parent/child
/parent/child?
/parent/child?firstparam=abc123
/parent/child?secondparam=def456
/parent/child?firstparam=abc123&secondparam=def456
/parent/child?secondparam=def456&firstparam=abc123
/parent/child?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child?thirdparam=ghi789
/parent/child/
/parent/child/?
/parent/child/?firstparam=abc123
/parent/child/?secondparam=def456
/parent/child/?firstparam=abc123&secondparam=def456
/parent/child/?secondparam=def456&firstparam=abc123
/parent/child/?thirdparam=ghi789&secondparam=def456&firstparam=abc123
/parent/child/?secondparam=def456&firstparam=abc123&thirdparam=ghi789
/parent/child/?thirdparam=ghi789";
for my $string(split /\n/, $r){
if (index($string,'?')!=-1){
substr($string, 0, index($string,'?')+1,"");
#say "string = ".$string;
if (index($string,'=')!=-1){
my #params = map{$_ = [split /=/, $_];}split/\&/, $string;
$"="\n";
say "$_->[0] === $_->[1]" for (#params);
say "######next########";
}
else{
#print "there is no params!"
}
}
else{
#say "there is no params!";
}
}
I have entries like that :
XYZABC------------HGTEZCW
ZERTAE------------RCBCVQE
I would like to get just HGTEZCW and RCBCVQE .
I would like to use a generic regex.
$temp=~ s/^\s+//g; (1)
$temp=~ s/^\w+[-]+//g; (2)
If i use (1) + (2) , it works.
It works i get : HGTEZCW, then RCBCVQE ...
I would like to know if it is possible to do that in one line like :
$temp=~ s/^\s+\w+[-]+//g; (3)
When I use (3), i get this result : XYZABC------------HGTEZCW
I dont understand why it is not possible to concat 1 + 2 in one line.
Sorry my entries was :
XYZABC------------HGTEZCW
ZERTAE------------RCBCVQE
Also, the regex 1 remove space but when i use regex2, it remove XYZABC------------ .
But the combination (3), don't work.
i have this XYZABC------------HGTEZCW
#Tim So there always is whitespace at the start of each string?
yes
Your regex (1) removes whitespace from the start of the string. So it does nothing on your example strings.
Reges (2) removes all alphanumerics from the start of the string plus any following dashes, returning whatever follows the last dash.
If you combine both, the regex fails because there is no whitespace \s+ could match - therefore the entire regex fails.
To fix this, simply make the whitespace optional. Also you don't need to enclose the - in brackets:
$temp=~ s/^\s*\w+-+//g;
This should do the trick.
$Str = '
XYZABC------------HGTEZCW
ZERTAE------------RCBCVQE
';
#Matches = ($Str =~ m#^.+-(\w+)$#mg);
print join "\n",#Matches ;
If you only need the last seven characters of each entry, you could do the following:
$temp =~ /.{7}$/;
Sorry in advance that this might be a little challenging to read...
I'm trying to parse a line (actually a subject line from an IMAP server) that looks like this:
=?utf-8?Q?Here is som?= =?utf-8?Q?e text.?=
It's a little hard to see, but there are two =?/?= pairs in the above line. (There will always be one pair; there can theoretically be many.) In each of those =?/?= pairs, I want the third argument (as defined by a ? delimiter) extracted. (In the first pair, it's "Here is som", and in the second it's "e text.")
Here's the regex I'm using:
=\?(.+)\?.\?(.*?)\?=
I want it to return two matches, one for each =?/?= pair. Instead, it's returning the entire line as a single match. I would have thought that the ? in the (.*?), to make the * operator lazy, would have kept this from happening, but obviously it doesn't.
Any suggestions?
EDIT: Per suggestions below to replace ".?" with "[^(\?=)]?" I'm now trying to do:
=\?(.+)\?.\?([^(\?=)]*?)\?=
...but it's not working, either. (I'm unsure whether [^(\?=)]*? is the proper way to test for exclusion of a two-character sequence like "?=". Is it correct?)
Try this:
\=\?([^?]+)\?.\?(.*?)\?\=
I changed the .+ to [^?]+, which means "everything except ?"
A good practice in my experience is not to use .*? but instead do use the * without the ?, but refine the character class. In this case [^?]* to match a sequence of non-question mark characters.
You can also match more complex endmarkers this way, for instance, in this case your end-limiter is ?=, so you want to match nonquestionmarks, and questionmarks followed by non-equals:
([^?]*\?[^=])*[^?]*
At this point it becomes harder to choose though. I like that this solution is stricter, but readability decreases in this case.
One solution:
=\?(.*?)\?=\s*=\?(.*?)\?=
Explanation:
=\? # Literal characters '=?'
(.*?) # Match each character until find next one in the regular expression. A '?' in this case.
\?= # Literal characters '?='
\s* # Match spaces.
=\? # Literal characters '=?'
(.*?) # Match each character until find next one in the regular expression. A '?' in this case.
\?= # Literal characters '?='
Test in a 'perl' program:
use warnings;
use strict;
while ( <DATA> ) {
printf qq[Group 1 -> %s\nGroup 2 -> %s\n], $1, $2 if m/=\?(.*?)\?=\s*=\?(.*?)\?=/;
}
__DATA__
=?utf-8?Q?Here is som?= =?utf-8?Q?e text.?=
Running:
perl script.pl
Results:
Group 1 -> utf-8?Q?Here is som
Group 2 -> utf-8?Q?e text.
EDIT to comment:
I would use the global modifier /.../g. Regular expression would be:
/=\?(?:[^?]*\?){2}([^?]*)/g
Explanation:
=\? # Literal characters '=?'
(?:[^?]*\?){2} # Any number of characters except '?' with a '?' after them. This process twice to omit the string 'utf-8?Q?'
([^?]*) # Save in a group next characters until found a '?'
/g # Repeat this process multiple times until end of string.
Tested in a Perl script:
use warnings;
use strict;
while ( <DATA> ) {
printf qq[Group -> %s\n], $1 while m/=\?(?:[^?]*\?){2}([^?]*)/g;
}
__DATA__
=?utf-8?Q?Here is som?= =?utf-8?Q?e text.?= =?utf-8?Q?more text?=
Running and results:
Group -> Here is som
Group -> e text.
Group -> more text
Thanks for everyone's answers! The simplest expression that solved my issue was this:
=\?(.*?)\?.\?(.*?)\?=
The only difference between this and my originally-posted expression was the addition of a ? (non-greedy) operator on the first ".*". Critical, and I'd forgotten it.