JAVASCRIPT

get everything between two characters regex

(?<=[)(.*?)(?=])

regex select string between two strings

(?<=This is).*?(?=sentence)
#dont forgive to escape special characters with 

regular expression to find a string between two characters

(?<=X)(.*?)(?=Y)

regex select string between two strings

(?s)(?<=This is).*?(?=sentence)

regex find string between two characters

part1 ([sS]*?) part2

regex match two characters

echo %H#E%L#L%O! | sed 's/[#%]//g'	#replaces every appearance of any of
two characters # and %