I want to validate a name for instance.
A name must be composed of words separated by " " or "-".
Example: "Jean-Luc Melenchon", "Xavi Hernandez"
If I got your requirements correctly, you want a name validator whose rule is to make sure each name contains atleast one space or one hyphen (-). You could use this regex:
^.*(\s|-)+.*$
(\s|-)+ means there should be atleast one space (\s) or hyphen (-)
.* allows any number of characters before and after the space
Will match successfully with
Jean-Luc Melenchon
Xavi Hernandez
Lionel Messi
Zlatan Ibrahimovic
Will not match with below (because they don't have a space or a hyphen)
Deco
Rivaldo
Kaka
O'Shea
If this is for a lab exercise, knock yourself out. If it's going to be used in a real-life application, do not think you know what a valid name is.
Take a look at
Using RegEx for validating First and Last names in Java
and
PHP Regex for human names
As Pascal Martin says in the latter,
one day or another, your code will meet a name that it thinks is "wrong"... And how do you think one would react when an application tells him "your name is not valid" ?
I tried this and it seems to be working fine
[A-Za-zàâéêèìôùûçÀÂÉÊÈÌÔÙÛÇ']+(\\s|\\-[A-Z]+)*
Related
I am trying to clean a set of names from a mysql table using mysql2 gem in ruby code, and then add the cleaned names to the table in a new column. I was able to do the cleaning except for one condition: Lowercasing all words, unless they come after a slash or after a comma or in parentheses. Here's a sample piece of code:
def cleaning_names(client)
q = "SELECT column_of_names FROM original_table;"
names = client.query(q)
names.map do |name|
clean_name = "#{name["column_of_names"]"
end
end
I used multiple gsub's to do the rest of the cleaning, but I can't find out how to use regex (in a gsub maybe) in order to downcase letters, or to leave them alone if they come after a slash or comma.
For example, one of the names I want is: 'County Clerk/DeKalb County' becomes ‘DeKalb County clerk’ or "1st circuit judge, Circuit Court" becomes "1st circuit judge (Circuit Court)". My code fixed the order, but doesn't do the proper capitalization.
Thanks :-)
I am learning regex and am having trouble getting google from email address
String
first.name#google.com
I just want to get google, not google.com
Regex:
[^#].+(?=\.)
Result: https://regex101.com/r/wA5eX5/1
From my understanding. It ignore # find a string after that until . (dot) using (?=\.)
What did I do wrong?
[^#] means "match one symbol that is not an # sign. That is not what you are looking for - use lookbehind (?<=#) for # and your (?=\.) lookahead for \. to extract server name in the middle:
(?<=#)[^.]+(?=\.)
The middle portion [^.]+ means "one or more non-dot characters".
Demo.
Updated answer:Use a capturing group and keep it simple :)
#(\w+)
Explanation by splitting it up
( capturing group for extraction )
\w stands for word character [A-Za-z0-9_]
+ is a quantifier for one or more occurances of \w
Regex explanation and demo on Regex101
I used the solution's regex for my task, but realized that some of the emails weren't that easy: foo#us.industries.com, foobar#tm.valves.net, andfoo#ge.test.com
To anyone who came here wanting the sub domain as well (or is being cut off by it), here's the regex:
(?<=#)[^.]*.[^.]*(?=\.)
This should be the regex:
(?<=#)[^.]+
(?<=#) - places the search right after the #
[^.]+ - take all the characters that are not dot (stops on dot)
So it extracts google from the email address.
As I was working to get the domain name of email addresses and none corresponded to what I needed:
To not catch subdomains
To match countries top domains (like .com.ar or co.jp)
For example, in test#ext.domain.com.mx I need to match domain.com.mx
So I made this one:
[^.#]*?\.\w{2,}$|[^.#]*?\.com?\.\w{2}$
Here is a link to regex101 to illustrate the regex: https://regex101.com/r/vE8rP9/59
You can get the sumdomain name (without the top-level domain ex: .com or .com.mx) by adding lookaround operators (but it will match twice in test#test.com.mx):
[^.#]*?(?=\.\w{2,}$)|[^.#]*?(?=\.com?\.\w{2}$)
Maybe not strictly a "full regex answer" but more flexible ( in case the part before the # is not "first.last") would be using cut:
cut -d # -f 2 | cut -d . -f 1
The first cut will isolate the part after # and the second one will get what you want.
This will work also for another kinds of email patterns : xxxx#server.com / xxx.yyy.zzz# server.com and so on...
Thanks everyone for your great responses, I took what you had and expanded it with labelled match-groups for easy extraction of separate parts.
Caveat : Regex.Speed = Slow
Another post mentioned how SLOW and nonperformant regexes are, and that is a fair point to remember. My particular need is targeting my own background/slow/reporting processes and therefore it doesn't matter how long it takes.
But it's good to remember whenever possible Regex should NOT be used in any sort of web page load or "needs-to-be-quick" kind of application. In that case you're much better off using substring to algorithmically strip down the inputs and throw away all the junk that I'm optionally matching/allowing/including here.
https://regex101.com/r/ZnU3OC/1
One Regex to rule them all...
Subdomain/Domain/TopLevelDomain/CountryCode extraction for Emails, domain lists, & URLs
Also handles ?Querystring=junk, Slashes/With/Paths, #anchors
Now with more broth, batteries not included
^(?<Email>.*#)?(?<Protocol>\w+:\/\/)?(?<SubDomain>(?:[\w-]{2,63}\.){0,127}?)?(?<DomainWithTLD>(?<Domain>[\w-]{2,63})\.(?<TopLevelDomain>[\w-]{2,63}?)(?:\.(?<CountryCode>[a-z]{2}))?)(?:[:](?<Port>\d+))?(?<Path>(?:[\/]\w*)+)?(?<QString>(?<QSParams>(?:[?&=][\w-]*)+)?(?:[#](?<Anchor>\w*))*)?$
not overly complicated at all... why would you even say that?
Substitution / Outputs
EXAMPLE INPUT: "https://www.stackoverflow.co.uk/path/2?q=mysearch&and=more#stuff"
EXAMPLE OUTPUT:
{
Protocol: "https://"
SubDomain: "www"
DomainWithTLD: "stackoverflow.co.uk"
Domain: "stackoverflow"
TopLevelDomain: "co"
CountryCode: "uk"
Path: "/path/2"
QString: "?q=mysearch&and=more#stuff"
}
Allowed/Compliant Domains : Should ALL MATCH
www.bankofamerica.com
bankofamerica.com.securersite.regexr.com
bankofamerica.co.uk.blahblahblah.secure.com.it
dashes-bad-for-seo.but-technically-still-allowed.not-in-front-or-end
bit.ly
is.gd
foo.biz.pl
google.com.cn
stackoverflow.co.uk
level_three.sub_domain.example.com
www.thelongestdomainnameintheworldandthensomeandthensomemoreandmore.com
https://www.stackoverflow.co.uk?q=mysearch&and=more
foo://5th.4th.3rd.example.com:8042/over/there
foo://subdomain.example.com:8042/over/there?name=ferret#nose
example.com
www.example.com
example.co.uk
trailing-slash.com/
trailing-pound.com#
trailing-question.com?
probably-not-valid.com.cn?&#
probably-not-valid.com.cn/?&#
example.com/page
example.com?key=value
* NOTE: PunyCodes (Unicode in urls) handled just fine with \w ,no extra sauce needed
xn--fsqu00a.xn--0zwm56d.com
xn--diseolatinoamericano-66b.com
Emails : Should ALL MATCH
first.name#google1.co.com
foo#us.industries.com,
foobar#tm.valves.net,
andfoo#ge.test.com
jane.doe#my-bank.no
john.doe#spam.com
jane.ann.doe#sandnes.district.gov
Non-Compliant Domains : Should NOT MATCH
either not long-enough (domain min length 2), or too long (64)
v.gd
thing.y
0123456789012345678901234567890123456789012345678901234567891234.com
its-sixty-four-instead-of-sixty-three!.com
symbols-not-allowed#.com
symbols-not-allowed#.com
symbols-not-allowed$.com
symbols-not-allowed%.com
symbols-not-allowed^.com
symbols-not-allowed&.com
symbols-not-allowed*.com
symbols-not-allowed(.com
symbols-not-allowed).com
symbols-not-allowed+.com
symbols-not-allowed=.com
TBD Not handled:
* dashes as start or ending is disallowed (dropped from Regex for readability)
-junk-.com
* is underscore allowed? i donno... (but it simplifies the regex using \w instead of [a-zA-Z0-9\-] everywhere)
symbols-not-allowed_.com
* special case localhost?
.localhost
also see:
Domain Name Rules :: Super handy ASCII Diagram of a URL
see: https://stackoverflow.com/a/66660651/738895 *
Side NOTE: lazy load '?' for subdomains{0,127}? currently needed for any of the cases with country codes... (example: stackoverflow.co.uk)
Matches these, but does NOT grab $NLevelSubdomains in a match group, can only grab 3rd level only.
This is a relatively simple regex, and it grabs everything between the # and the final domain extension (e.g. .com, .org). It allows domain names that are made up of non-word characters, which exist in real-world data.
>>> regex = re.compile(r"^.+#(.+)\.[\w]+$")
>>> regex.findall('jane.doe#my-bank.no')
['my-bank']
>>> regex.findall('john.doe#spam.com')
['spam']
>>> regex.findall('jane.ann.doe#sandnes.district.gov')
['sandnes.district']
I used this regular expression to get the complete domain name '.*#+(.*)' where .* will ignore all the character before # (by #+) and start extracting cpmlete domain name by mentioning paranthesis and complete string inside(except linebrake characters)
This is our URL structure:
http://www.disabledgo.com/access-guide/the-university-of-manchester/176-waterloo-place-2
http://www.disabledgo.com/access-guide/kingston-university/coombehurst-court-2
http://www.disabledgo.com/access-guide/kings-college-london/franklin-wilkins-building-2
http://www.disabledgo.com/access-guide/redbridge-college/brook-centre-learning-resource-centre
I am trying to create a list of groups based on the client names
/access-guide/[this bit]/...
So I can have a performance list of all our clients.
This is my regex:
/access-guide/(.*universit(y|ies)|.*colleg(e|es))/
I want it to group anything that has university/ies or college/es in it, at any point within that client name section of the URL.
At the moment, my current regex will only return groups that are X-University:
Durham-University
Plymouth-University
Cardiff-University
etc.
What does the regex need to be to have the list I'm looking for?
Do I need to have something at the end to stop it matching things after the client name? E.g. ([^/]+$)?
Thanks for your help in advance!
Depending upon your needs you may want to do:
/access-guide/([^/]*(?:university|universities|college|colleges)[^/]*)/
This will match names even if "university" or "college" is not at the end of the string. For example "college-of-the-ozarks" Note the non-capturing internal parenthesis, that should probably be used no matter what solution you go with, as you don't want to just match the word "university" or "college"
Live Example
Additionally, I don't know what may be in your but if you may have compound words you want to eliminate using a \b may be advisable. For instance if you don't want to match "miskatonic-postcollege" you may want to do something like this:
/access-guide/([^/]*\b(?:university|universities|college|colleges)\b[^/]*)/
If the client name section of the URL is after the access-guid/ and before the next /:
http://www.disabledgo.com/access-guide/the-university-of-manchester/176-waterloo-place-2
|----------------------------|
you need to use a negated character class to only match university before the regex reaches that rightmost / boundary.
As per the Reference:
You can extract pages by Page URL, Page Title, or Screen Name. Identify each one with a regex capture group (Analytics uses the first capture group for each expression)
Thus, you can use
/access-guide/([^/]*(universit(y|ies)|colleges?))
^^^^^
See demo.
The regex matches
/access-guide/ - leftmost boundary, matches /access-guide/ literally
[^/]* - any character other than / (so we still remain in that customer section)
(universit(y|ies)|colleges?) - university, or universities, orcollegeorcolleges` literally. Add more if needed.
How can I extract only top-level and second-level domain from a URL using regex? I want to skip all lower level domains. Any ideas?
Here's my idea,
Match anything that isn't a dot, three times, from the end of the line using the $ anchor.
The last match from the end of the string should be optional to allow for .com.au or .co.nz type of domains.
Both the last and second last matches will only match 2-3 characters, so that it doesn't confuse it with a second-level domain name.
Regex:
[^.]*\.[^.]{2,3}(?:\.[^.]{2,3})?$
Demonstration:
Regex101 Example
Updated 2019
This is an old question, and the challenge here is a lot more complicated as we start adding new vanity TLDs and more ccTLD second level domains (e.g. .co.uk, .org.uk). So much so, that a regular expression is almost guaranteed to return false positives or negatives.
The only way to reliably get the primary host is to call out to a service that knows about them, like the Public Suffix List.
There are several open-source libraries out there that you can use, like psl, or you can write your own.
Usage for psl is quite intuitive. From their docs:
var psl = require('psl');
// Parse domain without subdomain
var parsed = psl.parse('google.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'google'
console.log(parsed.domain); // 'google.com'
console.log(parsed.subdomain); // null
// Parse domain with subdomain
var parsed = psl.parse('www.google.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'google'
console.log(parsed.domain); // 'google.com'
console.log(parsed.subdomain); // 'www'
// Parse domain with nested subdomains
var parsed = psl.parse('a.b.c.d.foo.com');
console.log(parsed.tld); // 'com'
console.log(parsed.sld); // 'foo'
console.log(parsed.domain); // 'foo.com'
console.log(parsed.subdomain); // 'a.b.c.d'
Old answer
You could use this:
(\w+\.\w+)$
Without more details (a sample file, the language you're using), it's hard to discern exactly whether this will work.
Example: http://regex101.com/r/wD8eP2
Also, you can likely do that with some expression similar to,
^(?:https?:\/\/)(?:w{3}\.)?.*?([^.\r\n\/]+\.)([^.\r\n\/]+\.[^.\r\n\/]{2,6}(?:\.[^.\r\n\/]{2,6})?).*$
and add as much as capturing groups that you want to capture the components of a URL.
Demo
If you wish to simplify/modify/explore 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.
RegEx Circuit
jex.im visualizes regular expressions:
For anyone using JavaScript and wanting a simple way to extract the top and second level domains, I ended up doing this:
'example.aus.com'.match(/\.\w{2,3}\b/g).join('')
This matches anything with a period followed by two or three characters and then a word boundary.
Here's some example outputs:
'example.aus.com' // .aus.com
'example.austin.com' // .austin.com
'example.aus.com/howdy' // .aus.com
'example.co.uk/howdy' // .co.uk
Some people might need something a bit cleverer, but this was enough for me with my particular dataset.
Edit
I've realised there are actually quite a few second-level domains which are longer than 3 characters (and allowed). So, again for simplicity, I just removed the character counting element of my regex:
'example.aus.com'.match(/\.\w*\b/g).join('')
Since TLDs now include things with more than three-characters like .wang and .travel, here's a regex that satisfies these new TLDs:
([^.\s]+\.[^.\s]+)$
Strategy: starting at the end of the string, look for one or more characters that aren't periods or whitespace, followed by a single period, followed by one or more characters that aren't periods or whitespace.
http://regexr.com/3bmb3
With capturing groups you can achieve some magix.
For example, consider the following javascript:
let hostname = 'test.something.else.be';
let domain = hostname.replace(/^.+\.([^\.]+\.[^\.]+)$/, '$1');
document.write(domain);
This will result in a string containing 'else.com'. This is because the regex itself will match the complete string and the capturing group will be mapped to $1. So it replaces the complete string 'test.something.else.com' with '$1' which is actually 'else.com'.
The regex isn't pretty and can probably be made more dynamic with things like {3} for defining how many levels deep you want to look for subdomains, but this is just an illustration.
if you want all specific Top Level Domain name then you can write regular expression like this:
[RegularExpression("^(https?:\\/\\/)?(([\\w]+)?\\.?(\\w+\\.((za|zappos|zara|zero|zip|zippo|zm|zone|zuerich|zw))))\\/?$", ErrorMessage = "Is not a valid fully-qualified URL.")]
You can also put more domain name from this link:
https://www.icann.org/resources/pages/tlds-2012-02-25-en
The following regex matches a domain with root and tld extractions (named capture groups) from a url or domain string:
(?:\w+:\/{2})?(?<cs_domain>(?<cs_domain_sub>(?:[\w\-]+\.)*?)(?<cs_domain_root>[\w\-]+(?<cs_domain_tld>(?:\.\w{2})?(?:\.\w{2,3}|\.xn-+\w+|\.site|\.club))))\|
It's hard to say if it is perfect, but it works on all the test data sets that I have put it against including .club, .xn-1234, .co.uk, and other odd endings. And it does it in 5556 steps against 40k chars of logs, so the efficiency seems reasonable too.
If you need to be more specific:
/\.(?:nl|se|no|es|milru|fr|es|uk|ca|de|jp|au|us|ch|it|io|org|com|net|int|edu|mil|arpa)/
Based on http://www.seobythesea.com/2006/01/googles-most-popular-and-least-popular-top-level-domains/
World's most convuluted title I know, an example should explain it better. I have a large txt file in the below format, though details and amount of lines will change everytime:
Username: john_joe Owner: John Joe
Account:
CLI:
Default:
LGICMD:
Flags:
Primary days:
Secondary days:
No access restrictions
Expiration:
Pwdlifetime:
Last Login:
Maxjobs:
Maxacctjobs:
Maxdetach:
Prclm:
Prio:
Queprio:
CPU:
Authorized Privileges:
BYPASS
Default Privileges:
SYSPRV
This sequence is repeated a couple of thousand times for different users. I need to find every user (ideally the entire first line of the above) that has SYSPRV under "Default Permissions".
I know I could write an application to do this, I was just hoping their might be a nice regex I could use.
Cheers
^Username:\s*(\S+)((?!^Username).)*Default Privileges:\s+SYSPRV
with the option to make ^ match start of line, and to make dot match newlines, will isolate those records and capture the username in backreference no. 1. Tell me which language you're using, and I'll provide a code sample.
Explanation:
^Username:\s: match "Username" at the start of the line, a colon and any whitespace.
(\S)+": match any non-whitespace characters and capture them into backreference no. 1. This will be the Username.
((?!Username).)*: Match any character as long as it's not the "U" of "Username". This ensures that we won't accidentally cross over into the next record.
Default Privileges:\s+SYSPRV: match the required text.
So in Python, for example, you would use:
result = re.findall(r"(?sm)^Username:\s*(\S+)((?!^Username).)*Default Privileges:\s+SYSPRV", subject)