I have written the following Regex in PHP for use within preg_replace().
/\b\S*(.com|.net|.us|.biz|.org|.info|.xxx|.mx|.ca|.fr|.in|.cn|.hk|.ng|.pr|.ph|.tv|.ru|.ly|.de|.my|.ir)\S*\b/i
This regex removes all URLs from a string pretty effectively this far (though I am sure I can write a better one). I need to be able to add an exclusion though from a specific domain. So the pseudo code will look like this:
IF string contains: .com or .net or. biz etc... and does not contain: foo.com THEN execute condition.
Any idea on how to do this?
Just add a negative lookahead assertion:
/(?<=\s|^)(?!\S*foo\.com)\S*\.(com|net|us|biz|org|info|xxx|mx|ca|fr|in|cn|hk|ng|pr|ph|tv|ru|ly|de|my|ir)\S*\b/im
Also, remember that you need to escape the dot - and that you can move it outside the alternation since each of the alternatives starts with a dot.
Use preg_replace_callback instead.
Let your callback decide whether to replace.
It can give more flexibility if the requirements become too complicated for a simple regex.
Related
So basically I'm trying to select all content that is in /thank-you/hello/, so this can be /thank-you/hello/x/, /thank-you/hello/y/, /thank-you/hello/z/, etc.
This is what I'm using right now:
preg_match ('#^/thank-you/hello/#', $_SERVER['REQUEST_URI']
This block of code only works for stuff that is in /thank-you/hello/.
How should I change this snippet to include all the other folders that are after /hello/?
I suggest you read more about regex
I also recommend regex101 to test and study the site
In the desired pattern you can replace the desired word from .*?
.: Matches any character other than newline (or including line terminators with the /s flag)
a*: Matches zero or more consecutive a characters.
a?: Matches an a character or nothing.
They may seem a little incomplete without their examples
I suggest you see their examples on regex101
example:
preg_match('#^/thank-you/hello/.*?/#', $_SERVER['REQUEST_URI']);
It may not be exactly what you want
Or something may increase or decrease later and you may want to make a change
I think everyone should learn regex so that they can implement what they want according to their own desires.
I do not think it is a good idea to use patterns that you do not know what they mean
The thing was not very nice.
My regex so far:
(?<!not\s)(?<!n't\s)(nice|friendly|excelent|comfortable|easy access|good|clean|beautiful)
I want to match only words (nice,friendly... in this sentence...) if the sentence does not contain words: "not" or "n't" (a.k.a wasn't, isn't). A.k.a positive sentences.
But this regex works only for sentences like:
The thing was very not nice.
How to write lookbehind to check if the words "not" or "n't" are not in whatever position before my adjectives?
You could use a negative look ahead to check there isn't any not or n't anywhere in the string, and \K to throw out the part you don't want:
^(?!.*(?:not|n't)).*\K(nice|friendly|excellent|comfortable|easy access|good|clean|beautiful)
(?!...) will fail if what's inside it matches, (?:not|n't) is a non capturing group.
Kind in mind that this is a pretty simple check though. It wouldn't match nice in This is nice but not pretty. If you want to add more in depth syntax understanding, you'll have to dig deeper.
Lookbehinds must be fixed-length.
It would perhaps be easier to divide the task. First check if the sentence contains "nice", "friendly" etc., and then in a separate conditional, check if it doesn't contain a negation.
This would make it easier to detect double-negatives too :p
Input:
http://foo/bar/baz/../../qux/
Desired Output:
http://foo/qux/
This can be achieved using regular expression (unless someone can suggest a more efficient alternative).
If it was a forward look-up, it would be as simple as:
/\.\.\/[^\/]+/
Though I am not familiar with with how to make a backward look up for the first "/" (ie. not doing /[a-z0-9-_]+\/\.\./).
One of the solutions I thought of is to use strrev then apply forward look up regex (first example) and then do strrev. Though I am sure there is a more efficient way.
Not the clearest question I've ever seen, but if I understand what you're asking, I think you only need to switch around what you have like this:
/[^\/]+/\.\./
...then replace that with a /
Do that until no replacements are made and you should have what you want
EDIT
Your attempt seems to try to match a forward slash / and two dots \.\. followed by a slash / (or \/ - they should both match the same thing), then one or more non-slash characters[^/]+, terminated by a slash /. Flipping it around, you want to find a slash followed by one or more non-slash characters and a terminating slash, then two dots and a final slash.
You may be confused into thinking that the regex engine parses and consumes things as it goes (so you wouldn't want to consume a directory name that is not followed by the correct number of dots), but that's not how it typically works - a regex engine matches the entire expression before it replaces or returns anything. So, you can have two dots followed by a directory name, or a directory name followed by two dots - it doesn't make a difference to the engine.
If your attempt is using the slash-enclosed Perl-style syntax, then you would of course need to use \/ for any slashes you're trying to match such as the middle one, but I would also recommend matching and replacing the enclosing slashes in the url as well: I think the PHP would be something like
preg_replace('/\/[^\/]+\/\.\.\//', '/', $input)
(??)
Technically what do you want is replace segments of '/path1/path2/../../' by '/' what is needed to do that is match 'pathx/'^n'../'^n that is definetly NOT a regular expression (Context Free Lenguaje) ... but most of Regex libraries supports some non regular lenguajes and can (with a lot of effort) manage those kind of lenguajes.
An easy way to solve it is stay in Regular Expressions and cycle several times, replacing '/[^./]+/../' by ''
if you still to do it in a single step, Lookahead and grouping is needed, but it will be hard to write it, (I'm not so used on, but I will try)
EDIT:
I've found the solution in only 1 REGEX... but should use PCRE Regex
([^/.]+/(?1)?\.\./)
I've based my solution on the folowing link:
Match a^n b^n c^n (e.g. "aaabbbccc") using regular expressions (PCRE)
(note that dots are "forbidden" in the first section, you cannot have path.1/path.2/ if you whant to is quite more complex because you should admit them but forbid '../' as valid in the first section
this sub expression is for admiting the path names like 'path1/'
[^/.]+/
this sub expression is for admiting the double dots.
\.\./
you can test the regexp in
https://www.debuggex.com/
(remember to set it in PCRE mode)
Here is a working copy:
https://eval.in/52675
I need the regex to find function calls in strings in php, I have tried to search here on stackoverflow but none of the ones i've tried worked.
this pattern: ^.*([\w][\(].*[\)])
This will match: functionone(fgfg) but also functionone(fgfg) dhgfghfgh functiontwo() as one match. Not 2 separate matches (as in functionone(fgfg) and functiontwo().
I don't know how to write it but I think this is what I need.
1. Any string, followed by (
2. Any string followed by )
And then it should stop, not continue. Any regex-gurus that can help me out?
I see 5 issues with your regex
If you want to match 2 functions in the same row, don't use the anchor ^, this will anchor the regex to the start of the string.
You then don't need .* at the start maybe more something like \w+ (I am not sure what the spec of a function name in PHP is)
if there is only one entry in a character class (and its not a negated one), you don't need the character class
The quantifier between the brackets needs to be a lazy one (followed by a ?). So after this 4 points your regex would look something like
\w+\(.*?\)
Is a regex really the right tool for this job?
Don't use regexp for this... use PHP's built-in tokenizer
A function signature is not a regular language. As such, you cannot use a regular expression to match a function signature. Your current regex will match signatures that are NOT valid function signatures.
What I would suggest you use is the PHP tokenizer.
i have this regex code
/^(https?:\/\/+[\w\-]+\.[\w\-]+)/i
it works but there is a problem
you NEED http:// in the url for it to validate, and what i am making, the user will not want to add http:// to the url they want to just have example.com, if its possible i need it to work weather it has http:// or not
i don't know how to make my own regex, and ive searched but cannot find a one that does what i need, unless im just not looking in the right place. (Google :P)
Don't bother with regex. Use parse_url function.
You can just make it optional
/^((?:https?:\/\/+)?[\w\-]+\.[\w\-]+)/i
The (?:) around the part you don't want to have is a non capturing group, the ? afterwards makes it optional.
I'm not sure what the + after the second slash is good for, it says at least one of the preceding character. That means it allows also stuff like http://////////.
I hope you are aware, that this regex is far from matching valid URLs.
For example it will match stuff like
http://////////------------.-
or at least
http://N.O
^ after this position you can write what you want and it will match valid.
Here on Regexr you can see what your regex is matching.
See Purple Coder's answer for a probably better solution.
/^((https?:\/\/+)?[\w-]+.[\w-]+)/i
I'm using this :
// Validate that the string contains at least a dot .
var filterWebsite = /^([a-zA-Z0-9:_\.\-/])+\.([a-zA-Z0-9_\.\-/])+$/;