UPDATE: It fails “with two ff before oo” as @Ciantic pointed out in the comments. ^(f(o[^o]|[^o])|[^f])*$ NOTE: It is much much easier just to negate a match on the client side instead of using the above regex. The regex assumes that each line ends with a newline char if it is not then see C++’s … Read more
Use negative lookahead for this. (?!foo123).+ matches any string except foo123 If you want to match empty string also, use (?!foo123).* In your case (according to the comment) the required regex is (?!P[0-9]{1,}).+. It matches P and 123, but not P123.
This is not easily possible. Regular expressions are designed to match things, and this is all they can do. First off: [^] does not designate an “excludes group”, it designates a negated character class. Character classes do not support grouping in any form or shape. They support single characters (and, for convenience, character ranges). Your … Read more
Your first two sentences contradict each other. “in \w but is not in \d” includes underscore. I’m assuming from your third sentence that you don’t want underscore. Using a Venn diagram on the back of an envelope helps. Let’s look at what we DON’T want: (1) characters that are not matched by \w (i.e. don’t … Read more
Your solution is half right. The match you see is for the other characters. What you want to say is something like “hey! I do not want to see this character in the entire string”. In that case you do: Regex.IsMatch(“103″,”^[^0]*$”)
try this: ^(?!.*DontMatchThis).*$
It only will do this if you have the option selected at the bottom: Disallow insecure . and [^…] in /RegExp/ From the docs: true if . and [^…] should not be allowed in RegExp literals. These forms should not be used when validating in secure applications. So the answer your question, if you start … Read more
^(?:(?!boon\.ini|http).)*$\r?\n? (taken from RegexBuddy’s library) will match any line that does not contain boon.ini and/or http. Is that what you wanted?
Answer to the question: “A Regular Expression to match anything that isn’t “foo” and “bar”?” ^(?!foo$|bar$).* would do exactly that. ^ # Start of string (?! # Assert that it’s impossible to match… foo # foo, followed by $ # end of string | # bar$ # bar, followed by end of string. ) # … Read more
You can use a look behind to make sure it is not at the beginning. (?<!^)aaa