I wonder if anyone could make a suggestion how i achieve the following?
I have a regex which suffices in the validation of email addresses which is as follows:
^(\b[A-Za-z0-9._%+-]+#[A-Za-z0-9.-]+\.[A-Za-z]{2,4}\b)*$
Its a loose validator but as i said, it suffices for what we need. What I need to do if possible is validate on the following criteria:
1) validate email addresses based on the above format
2) if not an email address as above, check if value is N/A or n/a
Appreciate anyones help,
Thanks
Jon
With little modifications to your original expression you can acheive what you wanted...
You can use Or operator to match multiple patterns. (PatternA)|(PatternB)|(PatternC) will match for all three patterns A, B & C. So, below should work.
((\b[A-Za-z0-9._%+-]+#[A-Za-z0-9.-]+\.[A-Za-z]{2,4}\b))|(N/A)|(n/a)
Or the below should also work
([\w-\._\+%]+#(?:[\w-]+\.)+[\w]{2,6})|(N/A)|(n/a)
Source: http://RegExr.com?3563b
You can try this regex:
^(\b[Nn]\/[Aa]|(?:[A-Za-z0-9._%+-]+#[A-Za-z0-9.-]+\.[A-Za-z]{2,4})\b)$
Related
I'm learning regular expressions and I'm having trouble extracting the domain from the email address. I have an email address: example#gmail.com. I need to use a regular expression to extract #gmail (along with the # symbol). I should end up only getting example. I've already tried this:
your text#(\w+)
and this
your text(?<=#)[^.]+(?=.).*
but those expressions didn't work properly. I'd appreciate your help.
I just tried a simple look behind - #(?<=#).* it will match #google.com you can also group the entire expression and can change it according to single and multi-line matches.
#(?<=#).*
I'm working with a system that processes email addresses and need to tell it to not process email addresses that contain 'auto#' using a regular expression.
Example email addresses:
us.group-email-name.auto#somedomain.com
us.group-email-name#somedomain.com
The regex should only match the second and not the first.
Is this possible?
Thanks in advance for your time!
If you don't have to validate the email addresses and there is no way to do it with a quick built-in substring finder, you can use this regex:
((?!auto#).)*
A far better option would be a simple substring finder method/function, like Java's
emailAddress.indexOf("auto#")
which returns -1 if it doesn't find a match.
I want to validate hostnames (ie x.y.z format). Currently I'm using the regular expression below, but it is not working.
It accepts x.y.z.a etc. I want to restrict it to only accept x.y.z. Does anyone know how I can fix it?
/^([a-z0-9]+(-[a-z0-9]+)*\.)+([a-z]{2,12})$/i
Just replace the + modifier with {1,2}:
/^([a-z0-9]+(-[a-z0-9]+)*\.){1,2}([a-z]{2,12})$/i
And, if you don't need the capture groups:
/^(?:[a-z0-9]+(?:-[a-z0-9]+)*\.){1,2}[a-z]{2,12}$/i
If you want exactly 3 parts (x.y.z), use {2} instead of {1,2}
/^(?:[a-z0-9]+(?:-[a-z0-9]+)*\.){2}[a-z]{2,12}$/i
This will do the job. Above regex will match only x.y.z format
^([a-z0-9]\.){2}[a-z0-9]$
Two times x. format with a x at the end.
I am a email spam quarantine administrator and I can write regular expression rules to block email messages. There is a common classification of email spam hitting our domain such that the username of any of our email addresses is spoofed in front of some other domain.
For example, suppose my email address is jwclark#domain.com. In that case, spammers are writing to me from all kinds of other domains that start with my username such as:
jwclark1234#whatever.com
jwclark#wrongdomain.com
jwclark#a.domain.com
How can I write a regular expression rule to match everything including jwclark and any wildcards, but not match the original jwclark#domain.com? I would like a regex that matches everything above except for my actual example email address jwclark#domain.com.
I've made this regexp here
^jwclark.*[#](?!domain\.com).*$
it's in javascript format, but it should be easy to adapt to php or something else.
Given the nature of your problem, you might be better off making a regex builder function that makes the proper regexp for you, given the parameters.
Or, actually use a different approach. I recently found out how to parse ranges of floating point numbers with regexp, but that doesn't make it the proper solution to finding numbers within ranges. :P
edit - fixed silly redundancy thanks to zx81
edit - change to comply with strange limitations:
^jwclark.{0,25}[#][^d][^o][^m][^a][^i][^n].{0,25}\.com.{0,25}$
demo for the strange one
Say you have an IP address: 74.125.45.100 so its A.B.C.D
Is there a way to use RegEx to get A,B,C separately?
If it is just to extract the numbers from the IP and not to validate the IP address then you could just do:
[0-9]
However, I think a simple String.Split(".") would be an easier option.
Something very simple yet ugly would work.. giving you four groups one for each octet.
(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})
([0-9]+).([0-9]+).([0-9]+).([0-9]+)
...should do it. It's no validating regex though, allows numbers beyond 255 for each part.
Here's a crazy validating one:
\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b
Credit to last regex goes to RegexBuddy makers.
/(\d+)\.(\d+)\.(\d+)\.(\d+)/
First port of call for regex... RegEx Library
While others have pointed out various good regexps; May I ask why you absolutely must use regular expressions for that? It will be slow and error-prone. Most platforms do have integrated IP address functionality, or provide a way to call to inet_aton.
In case someone needs a validating RegEx for (all possible) IPv4 addresses:
([^\d.]|^)([01]{0,1}\d{1,2}|2[0-5][0-5])[.]([01]{0,1}\d{1,2}|2[0-5][0-5])[.]([01]{0,1}\d{1,2}|2[0-5][0-5])[.]([01]{0,1}\d{1,2}|2[0-5][0-5])([^\d]|$)
The IP is contained in 2nd, 3rd and 4th parameters. 1st and last are not used. Those are necessary otherwise a wrong IP like:
999.1.2.3
would be catched as "99.1.2.3". I am not sure if you want to allow IP ending with a dot, e.g.
1.2.3.4.
If not, change the last part to ([^\d.]|$). I do not allow any dots in front of it though.
I still think this RegEx is a messed monster :) and a better solution would be to validate by hand using a function.