Check for url slash count pattern - php

Question

I am trying to write an regualr expression to match invalid url patterns
I want to match following pattern :
/article/test-string/
Above is invalid url, but following are valid
/article/abc/test-string/ and /article/xyz/abc/test-string/
I want to match those which have only one value after article slash.
Please help, I am trying using following, but it is matching all :
/article/(.*)/$

Answer 1

.* matches 0 or more of any character so /article/(.*)/$ will match all the URIs that have /article/ in it.
You can use this regex to validate only only one non-slash component after /article/:
$re = '~^/article/[^/]*/$~';
[^/]* # matches 0 or more of any character that is not /
/$ # matches / in the end
~ is used as regex delimiter to avoid escaping /

Answer 2

~^/article/(.*)+/(.*)/$~gm
^ assert position at start of a line
/article/ matches the characters /article/ literally (case sensitive)
1st Capturing group (.*)+
Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
Note: A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
/ matches the character / literally
2nd Capturing group (.*)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
Note: A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
.* matches any character (except newline)
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
/ matches the character / literally
$ assert position at end of a line
g modifier: global. All matches (don't return on first match)
m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
$re = "~^/article/(.*)+/(.*)/$~m";
$str = "/article/xyz/abc/test-string/\n/article/test-string/";
preg_match_all($re, $str, $matches);
source https://regex101.com/