Trying to create a regular expression that excludes results of a substring is present.
Data Set:
http://www.cnn.com/test1
http://www.cnn.com/test3
http://www.cnn.com/test5
http://www.stackflow.com/test4
http://www.cnn.com/test3
http://www.cnn.com/test4
exclude:
find all cnn.com sites
that don't have /test3
Results:
http://www.cnn.com/test1
http://www.cnn.com/test5
http://www.cnn.com/test4
Figured it out: (www.cnn.com)(?!/test3)
If you want to avoid matching strings like http://www.cnn.com/test/test3 then you can use a negtive lookbehind at the end of the string
cnn\.com.*(?<!test3)$
I'm guessing this would be fastest:
cnn\.com(?!\/test3)[a-zA-Z0-9-._~:?##!$&'*+,;=`.\/\(\)\[\]]*
because you restrict the URL to allowed characters only.
Related
I need to create a regex to validate urls. Currently the regex I am using allows one or multiple occurrences of /text.
For example:
/text/text
/text
Regex: ^(\/[a-zA-Z\d\-\_]+)+?$
My requirement is I want to use this regex in a validator such that it allows /* in urls but only at the end.
For example:
/text/text/* - Valid
/text/* - Valid
/text/*/text - invalid
Can someone please help me out with this? Thanks
^\/([\w-]*)(\/\1)*((?!\1)[\w-\/])*$
Try this.See demo.
http://regex101.com/r/kP4pZ2/16
I have a set of strings that I'd like to parse in MATLAB 2012 that all have the following format:
string-int-int-int-int-string
I'd like to pluck out the third integer (the rest are 'don't cares'), but I haven't used MATLAB in ages and need to refresh on regular expressions. I tried using the regular expression '(.*)-(.*)-(.*)-\d-(.*)' but no dice. I did check out the MATLAB regexp page, but wasn't able to figure out how to apply that information to this case.
Anyone know how I might get the desired result? If so, could you explain what the expression you're using is doing to get that result so that others might be able to apply the answer to their unique situation?
Thanks in advance!
str = 'XyzStr-1-2-1000-56789-ILoveStackExchange.txt';
[tok] = regexp(str, '^.+?-.+?-.+?-(\d+?)-.+?-.+?', 'tokens');
tok{:}
ans =
'1000'
Update
Explanation, upon request.
^ - "Anchor", or match beginning of string.
.+? - Wildcard match, one or more, non-greedy.
- - Literal dash/hyphen.
(\d+?) - Digits match, one or more, non-greedy, captured into a token.
^.*?-.*?-.*?-(\d+)-.*?-.*?$
OR
^(?:[^-]*?-){3}(\d+)(?:.*?)$
Group1 now contains your required data
I'm quite bad with regex, and I'm looking to match a criteria.
This is a regex expression that should go emmbed into the url for a firewall, so It will block any url that is not like the list at the end.
This is what Im currently using but its not working:
http://www.youtube.com/(*.*)list=UUFwtOm4N5djdcuTAlNIWJaQ
This is the example url (to be blocked):
http://www.youtube.com/watch?NR=1&feature=fvwp&v=P1b5VY_Bp_o&list=UUFwtOm4N5djdcuTAlNIWJaQ
I'm trying to make a regex that will Success fully match when NR=1 or feature=fvwp
are NOT present, I asume I can do it like this: (?!^feature=fvwp$) but the v= and list=UUFwtOm4N5djdcuTAlNIWJaQ are allowed.
Also the v= should be limited to any character (uppercase and lowercase) and 11 length, I assume its: /^[a-z0-9]{11}$/
How can I build all that together and make it work so it would allow and match only on this urls excluding from allowing the previous criterias that I explained:
http://www.youtube.com/watch?v=4eK_RWpTgcc&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
http://www.youtube.com/watch?v=TLRl85TJwZM&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
http://www.youtube.com/watch?v=QEV9yqrpxkc&feature=BFa&list=UUFwtOm4N5djdcuTAlNIWJaQ
Can you block based on matching by regex? If so, just use
(.*)www\.youtube\.com/watch\?NR=1&feature=fvwp and block whatever matches that.
I want to extract the "en" from the following url so it can be re-written.
contact/default.aspx?lang=en
/contact/default.aspx?lang=en-us&id=1
/contact/default.aspx?id=1111&lang=en
The above examples should be rewritten as:
/contact/en/default.aspx
Unfortunately IIS7 does not support lookbehinds so this peice of regex cannot be used:
(?<=lang\=)(.+)
Any ideas how i can match the value part of the query string?
Thanks
I would do
.*?(&|\?)lang=([^&]+).*
and use the capture group 1
Here's the regular expression I use, and I parse it using CAtlRegExp of MFC :
(((h|H?)(t|T?)(t|T?)(p|P?)(s|S?))://)?([a-zA-Z0-9]+[\.]+[a-zA-Z0-9]+[\.]+[a-zA-Z0-9])
It works fine except with one flaw. When URL is preceded by characters, it still accepts it as a URL.
ex inputs:
this is a link www.google.com (where I can just tokenize the spaces and validate each word)
is...www.google.com (this string still matches the RegEx above :( )
Please help...
Thanks...
Use the IgnoreCase flag instead of catering for each case.
Stick a ^ at the beginning if you want the start of the string to be the start of the URL
You're missing a lot of characters from possible, valid URLs.
You need to tell the regex to only match at the start and end of the string. I'm not sure how you do that in VC++ - in most regexs you enclose the pattern with ^ and $. The ^ says "the start of the string" and the $ says "the end of the string."
^(((h|H?)(t|T?)(t|T?)(p|P?)(s|S?))\://)?([a-zA-Z0-9]+[\\.]+[a-zA-Z0-9]+[\\.]+[a-zA-Z0-9])$
The second is matching because the string still contains a valid URL.
How about using CUrl (that is, 'C-Url', in ATL, not curl as in libcurl) which can 'parse' urls with CUrl::CrackUrl . If that function returns FALSE you assume it's not a valid URL.
That said, decomposing URL is sufficiently complex to warrant a proper parser, not a regex based decomposition. Cfr. rfc 2396 etc. for an overview on the complexities.
Start the regex with ^ to and end it with $ to have the regex match only if the entire sting matches (if that's what you want):
^(((h|H?)(t|T?)(t|T?)(p|P?)(s|S?))\://)?([a-zA-Z0-9]+[\.]+[a-zA-Z0-9]+[\.]+[a-zA-Z0-9])$
What about this one: (((f|ht)tp://)[-a-zA-Z0-9#:%_\+.~#?&//=]+) ?
This Regular Expression has been tested to work for the following
http|https://host[:port]/[?][parameter=value]*
public static final String URL_PATTERN = "(https?|ftp)://(www\\.)?(((([a-zA-Z0-9.-]+\\.){1,}[a-zA-Z]{2,4}|localhost))|((\\d{1,3}\\.){3}(\\d{1,3})))(:(\\d+))?(/([a-zA-Z0-9-._~!$&'()*+,;=:#/]|%[0-9A-F]{2})*)?(\\?([a-zA-Z0-9-._~!$&'()*+,;=:/?#]|%[0-9A-F]{2})*)?(#([a-zA-Z0-9._-]|%[0-9A-F]{2})*)?";
PS. It also validates on localhost link.
(Thoroughly written by me :-))