These are the regular expressions patterns : In reference with THM Regex Room
Charsets :
To search for a particular alphabets/Numerics we use []
Ex 1 : [fF]ile searches for File or file word
Ex 2 : [Ff]ile[1-10] searches for File1,File2,…File10 and same thing with file1…file10
Ex 3 : [Ff]ile[^7] dosen’t specifically show File7 or file7
Ex 4 : [cbh]at gives cat, hat and bat
Wildcards :
This is used to match any character at place of . to search for . we use
Ex 1 : .at will match bat, aat, cat, dat, 3at, @at literally anything
Ex 2 : example\.com matches example.com
Optionals :
This is to match optional characters using ?
Ex 1 : abc? matches ab and abc since c is optional
Ex 2: cats? matches cat and cats
Ex 2: a(bc)? makes bc as optional so matches a and abc
Repetition :
For repetitions we use * or +
+ - repetition with 1 or more times
* -repetition with 0 or more times
Ex 1 : [Cc]ats* matches cats, Cat, Catss, Catssss, catssssss… etc.
Ex 2 : [Ca]ats+ matches Cats, cats, Catssss… but not cat