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capture group with optional second capture group containing first group pattern [duplicate]

This question already has answers here:
Regular expression to stop at first match
(9 answers)
Closed 2 years ago.
I have this gigantic ugly string:
J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM
J0000010: Project name: E:\foo.pf
J0000011: Job name: MBiek Direct Mail Test
J0000020: Document 1 - Completed successfully
I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time).
Here's the regex I've been playing with:
Project name:\s+(.*)\s+J[0-9]{7}:
The problem is that it doesn't stop until it hits the J0000020: at the end.
How do I make the regex stop at the first occurrence of J[0-9]{7}?

Make .* non-greedy by adding '?' after it:
Project name:\s+(.*?)\s+J[0-9]{7}:

Using non-greedy quantifiers here is probably the best solution, also because it is more efficient than the greedy alternative: Greedy matches generally go as far as they can (here, until the end of the text!) and then trace back character after character to try and match the part coming afterwards.
However, consider using a negative character class instead:
Project name:\s+(\S*)\s+J[0-9]{7}:
\S means “everything except a whitespace and this is exactly what you want.

Well, ".*" is a greedy selector. You make it non-greedy by using ".*?" When using the latter construct, the regex engine will, at every step it matches text into the "." attempt to match whatever make come after the ".*?". This means that if for instance nothing comes after the ".*?", then it matches nothing.
Here's what I used. s contains your original string. This code is .NET specific, but most flavors of regex will have something similar.
string m = Regex.Match(s, #"Project name: (?<name>.*?) J\d+").Groups["name"].Value;

I would also recommend you experiment with regular expressions using "Expresso" - it's a utility a great (and free) utility for regex editing and testing.
One of its upsides is that its UI exposes a lot of regex functionality that people unexprienced with regex might not be familiar with, in a way that it would be easy for them to learn these new concepts.
For example, when building your regex using the UI, and choosing "*", you have the ability to check the checkbox "As few as possible" and see the resulting regex, as well as test its behavior, even if you were unfamiliar with non-greedy expressions before.
Available for download at their site:
http://www.ultrapico.com/Expresso.htm
Express download:
http://www.ultrapico.com/ExpressoDownload.htm

(Project name:\s+[A-Z]:(?:\\w+)+.[a-zA-Z]+\s+J[0-9]{7})(?=:)
This will work for you.
Adding (?:\\w+)+.[a-zA-Z]+ will be more restrictive instead of .*

Regular Expression first coincidense [duplicate]

This question already has answers here:
Regular expression to stop at first match
(9 answers)
Closed 2 years ago.
I have this gigantic ugly string:
J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM
J0000010: Project name: E:\foo.pf
J0000011: Job name: MBiek Direct Mail Test
J0000020: Document 1 - Completed successfully
I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time).
Here's the regex I've been playing with:
Project name:\s+(.*)\s+J[0-9]{7}:
The problem is that it doesn't stop until it hits the J0000020: at the end.
How do I make the regex stop at the first occurrence of J[0-9]{7}?

Make .* non-greedy by adding '?' after it:
Project name:\s+(.*?)\s+J[0-9]{7}:

Using non-greedy quantifiers here is probably the best solution, also because it is more efficient than the greedy alternative: Greedy matches generally go as far as they can (here, until the end of the text!) and then trace back character after character to try and match the part coming afterwards.
However, consider using a negative character class instead:
Project name:\s+(\S*)\s+J[0-9]{7}:
\S means “everything except a whitespace and this is exactly what you want.

Well, ".*" is a greedy selector. You make it non-greedy by using ".*?" When using the latter construct, the regex engine will, at every step it matches text into the "." attempt to match whatever make come after the ".*?". This means that if for instance nothing comes after the ".*?", then it matches nothing.
Here's what I used. s contains your original string. This code is .NET specific, but most flavors of regex will have something similar.
string m = Regex.Match(s, #"Project name: (?<name>.*?) J\d+").Groups["name"].Value;

I would also recommend you experiment with regular expressions using "Expresso" - it's a utility a great (and free) utility for regex editing and testing.
One of its upsides is that its UI exposes a lot of regex functionality that people unexprienced with regex might not be familiar with, in a way that it would be easy for them to learn these new concepts.
For example, when building your regex using the UI, and choosing "*", you have the ability to check the checkbox "As few as possible" and see the resulting regex, as well as test its behavior, even if you were unfamiliar with non-greedy expressions before.
Available for download at their site:
http://www.ultrapico.com/Expresso.htm
Express download:
http://www.ultrapico.com/ExpressoDownload.htm

(Project name:\s+[A-Z]:(?:\\w+)+.[a-zA-Z]+\s+J[0-9]{7})(?=:)
This will work for you.
Adding (?:\\w+)+.[a-zA-Z]+ will be more restrictive instead of .*

How to regex Zapier and get output?

I regularly receive emails from the same person, each containing one or more unique identifying codes. I need to get those codes.
The email body contains a host of inconsistent email content, but it is the strings I am interested in. They look like...
loYm9vYzE6Z-aaj5lL_Og539wFer0KfD
FuZTFvYzE68y8-t4UgBT9npHLTGmVAor
JpZDRwYzE6dgyo1legz9sqpVy_F21nx8
ZzZ3RwYzE63P3UwX2ANPI-c4PMo7bFmj
What the strings seem to have in common is, they are all 32 characters in length and all composed of a mixture of both uppercase, lowercase, numbers and symbols. But a given email may contain none, one or multiple, and the strings will be in an unpredictable position, not on adjacent lines as above.
I wish to make a Zap workflow in Zapier, the linking tool for web services, to find these strings and use them in another app - ie. whenever a string is found, create a new Trello card.
I have already started the workflow with Zapier's "Gmail" integration as a "trigger", specifically a search using the "from:" field corresponding to the regular sender. That's the easy part.
But the actual parsing of the email body is foxing me. Zapier has a rudimentary email parser, but it is not suitable for this task. What is suitable is using Zapier's own "Code" integration to execute freeform code - namely, a regular expression to identify those strings.
I have never done this before and am struggling to formulate working code. Zapier Code can take either Python (documentation) or Javascript (documentation). It supports data variables "input_data" (Python) or "inputData" (Javascript) and "output" (both).
See, below, how I insert the Gmail body in to "body" for parsing...
I need to use the Code box to construct a regular expression to find each unique identifier string and output it as input to the next integration in the workflow, ie. Trello.
For info, in the above screengrab, the existing "hello world" code in the box is Zapier's own test code. The fields "id" and "hello" are made available to the next workflow app in the chain.
But I need to do my process for all of the strings found within an email body - ie. if an email contains just one code, create one Trello card; but if an email contains four codes, create a Trello card for each of the four.
That is, there could be multiple outputs. I have no idea how this could work, since I think these workflows are only supposed to accommodate one action.
I could use some help getting over the hill. Thank-you.

David here, from the Zapier Platform team.
I'm glad you're showing interest in the code step. Assuming your assumptions (32 characters exactly) is always going to be true, this should be fairly straightforward.
First off, the regex. We want to look for a character that's a letter, number, or punctuation. Luckily, javascript's \w is equivalent to [A-Z0-9a-z_], which covers the bases in all of your examples besides the -, which we'll include manually. Finally, we want exactly 32 character length strings, so we'll ask for that. We also want to add the global flag, so we find all matches, not just the first. So we have the following:
/[\w-]{32}/g
You've already covered mapping the body in, so that's good. The javascript code will be as follows:
// stores an array of any length (0 or more) with the matches
var matches = inputData.body.match(/[\w-]{32}/g)
// the .map function executes the nameless inner function once for each
// element of the array and returns a new array with the results
// [{str: 'loYm9vYzE6Z-aaj5lL_Og539wFer0KfD'}, ...]
return (matches || []).map(function (m) { return {str: m} })
Here, you'll be taking advantage of an undocumented feature of code steps: when you return an array of objects, subsequent steps are executed once for each object. If you return an empty array (which is what'll happen if no keys are found), the zap halts and nothing else happens. When you're testing, there'll be no indicator that anything besides the first result does anything. Once your zap is on and runs for real though, it'll fan out as described here.
That's all it takes! Hopefully that all makes sense. ​Let me know if you've got any other questions!

Javascript Find a string between two strings, but keep each occurence of the match [duplicate]

This question already has answers here:
Regular expression to stop at first match
(9 answers)
Closed 2 years ago.
I have this gigantic ugly string:
J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM
J0000010: Project name: E:\foo.pf
J0000011: Job name: MBiek Direct Mail Test
J0000020: Document 1 - Completed successfully
I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time).
Here's the regex I've been playing with:
Project name:\s+(.*)\s+J[0-9]{7}:
The problem is that it doesn't stop until it hits the J0000020: at the end.
How do I make the regex stop at the first occurrence of J[0-9]{7}?

Make .* non-greedy by adding '?' after it:
Project name:\s+(.*?)\s+J[0-9]{7}:

Using non-greedy quantifiers here is probably the best solution, also because it is more efficient than the greedy alternative: Greedy matches generally go as far as they can (here, until the end of the text!) and then trace back character after character to try and match the part coming afterwards.
However, consider using a negative character class instead:
Project name:\s+(\S*)\s+J[0-9]{7}:
\S means “everything except a whitespace and this is exactly what you want.

Well, ".*" is a greedy selector. You make it non-greedy by using ".*?" When using the latter construct, the regex engine will, at every step it matches text into the "." attempt to match whatever make come after the ".*?". This means that if for instance nothing comes after the ".*?", then it matches nothing.
Here's what I used. s contains your original string. This code is .NET specific, but most flavors of regex will have something similar.
string m = Regex.Match(s, #"Project name: (?<name>.*?) J\d+").Groups["name"].Value;

I would also recommend you experiment with regular expressions using "Expresso" - it's a utility a great (and free) utility for regex editing and testing.
One of its upsides is that its UI exposes a lot of regex functionality that people unexprienced with regex might not be familiar with, in a way that it would be easy for them to learn these new concepts.
For example, when building your regex using the UI, and choosing "*", you have the ability to check the checkbox "As few as possible" and see the resulting regex, as well as test its behavior, even if you were unfamiliar with non-greedy expressions before.
Available for download at their site:
http://www.ultrapico.com/Expresso.htm
Express download:
http://www.ultrapico.com/ExpressoDownload.htm

(Project name:\s+[A-Z]:(?:\\w+)+.[a-zA-Z]+\s+J[0-9]{7})(?=:)
This will work for you.
Adding (?:\\w+)+.[a-zA-Z]+ will be more restrictive instead of .*

Why does my JavaScript RegExp not work as expected

I am writing a password screen, and the requirements for the password security are somewhere between 8 and 20 characters in length, must contain at least one Alpha character and at least one numeric character and at least one special character of [!##$%^&*].
I have cobbled together this regular expression, which appeared to work in C#, but when I started rewriting the code for a JavaScript validation, the regular expression is flagging what I thought were valid passwords as invalid.
Here is the regular expression as I assign it to RegExp:
var regExPatt = new RegExp('^(?=(?:.*[a-zA-Z]){1})(?=(?:.*\d){1})(?=(?:.*[!###$%^&*]){1})(?!.*\s).{8,20}$');
NOTE BENE: The double ## symbol is there to get the # symbol into the RegExp, otherwise it tries to treat partial strings like Razor variables and things go sideways fast.
Where did I go wrong with this regular expression? I know it is fairly complicated.
Passwords that work:
freddy1234%
freddy123$5
freddy12#45
freddy1#345
freddy!2345
Passwords that do not work:
test1234%
wilma1234%
Any ideas?

JavaScript developers should have knowledge about
RegExp object description
Regular Expressions chapter in the JavaScript Guide
Developers who want to use positive or negtive lookahead should take into account that this requires JavaScript v1.5 as it can be read on page New in JavaScript 1.5. But that should be no problem nowadays as this is a very old version released on November 2000 and all browsers used nowadays support v1.5 of JavaScript.
Lookbehind is not yet (JavaScript v1.8.5) supported by JavaScript at all.
A list of the JavaScript versions and which browser supports which JavaScript version can be found on Wikipedia page about JavaScript.
New in JavaScript contains the links to the pages explaining what was added in which version of JavaScript.