Consider the following strings
home
administrator
admin
admin/
admin/users/index
and preg_match("/^admin\/?(P<controller>[a-z-]+)?\/?(?P<action>[a-z-]+)?$/i", $input_line, $output_array);
it is working to match the last 3 strings as expected, but also matches 'administrator' returning 'istrator' as the "controller"
How do I make the '/' optional, but any other character not count. I have tried things like [^a-z]\/? but am at a loss. Is it possible?
the logic is;
1. match admin
2. next character(s) are all optional
2.1 if next character exists, it must be /
live example https://www.phpliveregex.com/p/oaQ
You may use optional non-capturing groups as containers around the named capturing groups where the patterns can be obligatory:
'~^admin(?:\/(?P<controller>[a-z-]+))?(?:\/(?P<action>[a-z-]+))?\/?$~i'
See the regex demo.
Details
^ - start of string
admin - the admin substring
(?:\/(?P<controller>[a-z-]+))? - an optional non-capturing group matching 1 or 0 repetitions of
\/ - a / char
(?P<controller>[a-z-]+) - Group controller: 1+ ASCII letters or - (also, consider using [^\/]+ instead to match any 1+ chars other than /)
(?:\/(?P<action>[a-z-]+))? - Group action: 1+ ASCII letters or - (also, consider using [^\/]+ instead to match any 1+ chars other than /)
\/? - an optional /
$ - end of string.
Related
Maybe some regex-Master can solve my problem.
I have a big list with many addresses with no seperators( , ; ).
The address string contains following Information:
The first group is the street name
The second group is the street number
The third group is the zipcode (optional)
The last group is the town name (optional)
As you can see on the image above the last two test strings are not matching.
I need the last two regex groups to be optional and the third group should be either 4 or 5 digits.
I tried (\d{4,5}) for allowing 4 and 5 digits. But this only works halfways as you can see here: https://regex101.com/r/ZurqHh/1
(This sometimes mixes the street number and zipcode together)
I also tried (?:\d{5})? to make the third and fourth group optional. But this destroys my whole group layout...
https://regex101.com/r/EgxeMy/1
This is my current regex:
/^([a-zäöüÄÖÜß\s\d.,-]+?)\s*([\d\s]+(?:\s?[-|+\/]\s?\d+)?\s*[a-z]?)?\s*(\d{5})\s*(.+)?$/im
Try it out yourself:
https://regex101.com/r/zC8NCP/1
My brain is only farting at this moment and i can't think straight anymore.
Please help me fix this problem so i can die in peace.
You can use
^(.*?)(?:\s+(\d+(?:\s*[-|+\/]\s*\d+)*\s*[a-z]?\b))?(?:\s+(\d{4,5})(?:\s+(.*))?)?$
See the regex demo (note all \s are replaced with \h to only match horizontal whitespaces).
Details:
^ - start of string
(.*?) - Group 1: any zero or more chars other than line break chars
(?:\s+(\d+(?:\s*[-|+\/]\s*\d+)*\s*[a-z]?\b))? - an optional non-capturing group matching
\s+ - one or more whitespaces
(\d+(?:\s*[-|+\/]\s*\d+)*\s*[a-z]?\b) - Group 2:
\d+ - one or more digits
(?:\s*[-|+\/]\s*\d+)* - zero or more sequences of zero or more whitespaces, -, +, | or /, zero or more whitespaces, one or more digits
\s* - zero or more whitespaces
[a-z]?\b - an optional lowercase ASCII letter and a word boundary
(?:\s+(\d{4,5})\b(?:\s+(.*))?)? - an optional non-capturing group matching
\s+ - one or more whitespaces
(\d{4,5}) - Group 3: four or five digits
(?:\s+(.*))? - an optional sequence of one or more whitespaces and then any zero or more chars other than line break chars as many as possible
$ - end of string.
Please note that the (?:\s+(.*))? optional group must be inside the (?:\s+(\d{4,5})...)? group to work.
It is difficult to parse addresses because we are halfway between formatted text and natural language. Here is a pattern that tries as much as possible to reduce the number of optional parameters to succeed with the examples offered without asking too much to the regex engine. To do this, I mainly rely on character classes, atomic groups, and a relatively accurate description of the street names. Obviously, all the examples of the question cannot be representative of reality and characters could be added or removed from the classes to deal with new cases. Nevertheless, the structure of this pattern is a good starting point.
~
^
(?<strasse> [\pL\d-]+ \.? (?> \h+ [\pL\d-]+ \.? )*? ) \h*
(?<nummer> \b (?> \d+ | [-+/\h]+ | [a-z] \b )*? )
(?: \h+ (?<plz> \d{4,5} )
\h+ (?<stadt> .+ ) )?
$
~mxui
demo
Note that in the above link you can also see a previous version of this pattern with a more accurate description of the street number (a bit more efficient but longer).
I searched & tried below RegExp, but, not working for my requirement. Please, provide PHP RegExp, which accepts at least one alphanumeric and optional underscore or hyphen, but, Underscore or Hyphen should not repeat twice in a row.
/^([a-z0-9]+-)*[a-z0-9]+$/i
Example formats
_test147
test
_a
test_test
test-test_, etc
You may use this regex in ignore case mode:
^[-_]?[a-z\d]+(?:[_-][a-z\d]+)*[-_]?$
RegEx Demo
RegEx Details:
^: Start
[-_]?: Match an optional _ or -
[a-z\d]+: Match 1+ of alphanumeric character
(?:: Start a non-capture group
[_-]: Match a _ or -
[a-z\d]+: Match 1+ of alphanumeric character
)*: End non-capture group. Repeat this group 0 or more times
[-_]?: Match an optional _ or -
$: End
Or else if you want even better performance then use this possessive quantifier regex:
^[-_]?[a-z\d]++(?:[_-][a-z\d]+)*[-_]?+$
/^([-_]?[a-z0-9]+)+[-_]?$/i
This has a repeating sequence with an optional hyphen or underscore followed by alphanumerics, and then allows another optional hyphen or underscore at the end.
Is there any way to make rule allow only example 1 and 3 and not all 4 of them?
/^(en\/|)([\d]{1,3})([-])(.+?)([\/])$/
examples:
12-blog/
12-blog/blog2/
en/12-blog/
en/12-blog/blog2/
https://www.phpliveregex.com/p/tFe
You might use an optional part for en/ followed by match 1-3 digits, - and match not a / 1+ times using a negated character class.
Note that you can omit the square brackets for [\d], [-] and [\/]. If you choose a different delimiter than / you don't have to escape the forward slash.
^(?:en/)?\d{1,3}-[^/]+/$
In parts
^ Start of string
(?:en/)? Optionally match en/
\d{1,3} Match 1-3 digits
- Match literally
[^/]+/ Match 1+ times any char except /
$ End of string
Regex demo | Php demo
I need to match a series of strings that:
Contain at least 3 numbers
0 or more letters
0 or 1 - (not more)
0 or 1 \ (not more)
These characters can be in any position in the string.
The regular expression I have so far is:
([A-Z0-9]*[0-9]{3,}[\/]?[\-]?[0-9]*[A-Z]*)
This matches the following data in the following cases. The only one that does not match is the first one:
02ABU-D9435
013DFC
1123451
03323456782
ADS7124536768
03SDFA9433/0
03SDFA9433/
03SDFA9433/1
A41B03423523
O4AGFC4430
I think perhaps I am being too prescriptive about positioning. How can I update this regex to match all possibilities?
PHP PCRE
The following would not match:
01/01/2018 [multiple / or -]
AA-AA [no numbers]
Thanks
One option could be using lookaheads to assert 3 digits, not 2 backslashes and not 2 times a hyphen.
(?<!\S)(?=(?:[^\d\s]*\d){3})(?!(?:[^\s-]*-){2})(?!(?:[^\s\\]*\\){2})[A-Z0-9/\\-]+(?!\S)
About the pattern
(?<!\S) Assert what is on the left is not a non whitespace char
(?=(?:[^\d\s]*\d){3}) Assert wat is on the right is 3 times a whitespace char or digit
(?!(?:[^\s-]*-){2}) Assert what is on the right is not 2 times a whitespace char a hyphen
(?!(?:[^\s\\]*\\){2}) Assert what is on the right is not 2 times a whitespace char a backslash
[A-Z0-9/\\-]+ Match any of the listed 1+ times
(?!\S) Assert what is on the right is not a non whitespace char
Regex demo
Your patterns can be checked with positive/negative lookaheads anchored at the start of the string:
at least 3 digits -> find (not necessarily consecutive) 3 digits
no more than 1 '-' -> assert absence of (not necessarily consecutive) 2 '-' characters
no more than 1 '/' -> assert absence of (not necessarily consecutive) 2 '/' characters
0 or more letters -> no check needed.
If these conditions are met, any content is permitted.
The regex implementing this:
^(?=(([^0-9\r\n]*\d){3}))(?!(.*-){2})(?!(.*\/){2}).*$
Check out this Regex101 demo.
Remark
This solution assumes that each string tested resides on its own line, ie. not just being separated by whitespace.
In case the strings are separated by whitespace, choose the solution of user #TheFourthBird (which essentially is the same as this one but caters for the whitespace separation)
You can test the condition for both the hyphen and the slash into a same lookahead using a capture group and a backreference:
~\A(?!.*([-/]).*\1)(?:[A-Z/-]*\d){3,}[A-Z/-]*\z~
demo
detailled:
~ # using the tild as pattern delimiter avoids to escape all slashes in the pattern
\A # start of the string
(?! .* ([-/]) .* \1 ) # negative lookahead:
# check that there's no more than one hyphen and one slash
(?: [A-Z/-]* \d ){3,} # at least 3 digits
[A-Z/-]* # eventual other characters until the end of the string
\z # end of the string.
~
To better understand (if you are not familiar with): these three subpatterns start from the same position (in this case the beginning of the string):
\A
(?! .* ([-/]) .* \1 )
(?: [A-Z/-]* \d ){3,}
This is possible only because the two first are zero-width assertions that are simple tests and don't consume any character.
I have already found helpful answers for a regex that matches twitter like username mentions in this answer and this answer
(?<=^|(?<=[^a-zA-Z0-9-_\.]))#([A-Za-z]+[A-Za-z0-9_]+)
(?<=^|(?<=[^a-zA-Z0-9-_\.]))#([A-Za-z]+[A-Za-z0-9-_]+)
However, I need to update this regex to also include usernames that has dots.
One or more dots are allowed in a username.
The username must not start or end with a dot.
No two consecutive dots are allowed.
Example of a matched string:
#valid.user.name
^^^^^^^^^^^^^^^^
Examples of non-matched strings:
#.user.name // starts with a dot
#user.name. // ends with a dot
#user..name // has two consecutive dots
You can use this refactored regex:
(?<=[^\w.-]|^)#([A-Za-z]+(?:\.\w+)*)$
RegEx Demo
RegEx Details:
(?<=[^\w.-]|^): Lookbehind to assert that we have start of line or any non-word, non-dot, non-hyphen character before current position
#: Match literal `#1
(: Start capture group
[A-Za-z]+: Match 1+ ASCII letters
(?:\.\w+)*: Match 0 or more instances of dot followed 1+ word characters
): End capture group
$: End
The (?<=^|(?<=[^a-zA-Z0-9-_\.])) is a positive lookbehind that requires a match to be at the start of the string or right after an alphanumeric, -, _, ., you may write it in a more compact way as (?<![\w.-]), a negative lookbehind.
Next, ([A-Za-z]+[A-Za-z0-9_]+) captures 1+ ASCII letters and then 1+ ASCII letters or/and underscores. You seem to make sure the first char is a letter, then any number of sequences of . and 1+ word chars are allowed, that is, you may use [A-Za-z]\w*(?:\.\w+)*.
As you do not want to match it if there is a . right after the expected match, you need to set a lookahead that will require a space or end of string, (?!\S).
So, combining it, you can use
'~(?<![\w.-])#([A-Za-z]\w*(?:\.\w+)*)(?!\S)~'
See the regex demo
Details
(?<![\w.-]) - no letters, digits, _, . and - immediately to the left of the current location are allowed
# - a # char
([A-Za-z]\w*(?:\.\w+)*) - Group 1:
[A-Za-z] - an ASCII letter
\w* - 0+ letters, digits, _
(?:\.\w+)* - 0+ sequences of
\. - dot
\w+ - 1+ letters, digits, _
(?!\S) - whitespace or end of string are required immediately to the right of the current location.
EDIT: Simpler version (same result)
^#[a-zA-Z](\.?[\w-]+)*$
Original
Another one:
^#[a-zA-Z][a-zA-Z_-]?(\.?[\w\d-]+){0,}$
^# starts with #
[a-zA-Z] first char
[a-zA-Z_-]? match a-zA-Z_- 0 or more times
( start group
\.? match . (optional)
[\w\d-]+ match a-zA-Z0-9-_ 1 or more times
) end group
{0,} repeat group 0 to infinite times
$ end
Tests
valid:
#validusername
#valid.user.name
#valid-user-name
#valid_user-name
#valid-user123_name
#a.valid-user123_name
not valid:
#-invalid.user
#_invalid.user
#1notvalid-user_123name33
#.user.name
#user.name.
#user..name