java - How to match regex over multiple lines -

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• match multiline text using regular expression 3 answers

i have body of text , trying find character sequence within it. string.contains() not work im trying use string.matches method , regular expression. current regex isn't working. here attempts:

"1stline\r\n2ndline".matches("(?im)^1stline$");  // returns false; expect true  "1stline\r\n2ndline".matches("(?im)^1stline$")  // returns false  "1stline\r\n2ndline\r\n3rdline".matches("(?im)^2ndline$")     "1stline\n2ndline\n3rdline".matches("(?im)^2ndline$")  "1stline\n2ndline\n3rdline".matches("(?id)^2ndline$") 

how should format regex returns true?

you need use s flag (not m flag).

it's called dotall option.

this works me:

  string input = "1stline\n2ndline\n3rdline";   boolean b = input.matches("(?is).*2ndline.*"); 

i found here.

note must use .* before , after regex if want use string.matches().

that's because string.matches() attempts match entire string pattern.

(.* means 0 or more of character when used in regex)

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another approach, found here:

  string input = "1stline\n2ndline\n3rdline";   pattern p = pattern.compile("(?i)2ndline", pattern.dotall);   matcher m = p.matcher(input);   boolean b = m.find();   print("match found: " + b); 

i found googling "java regex multiline" , clicking first result.

(it's if answer written you...)

there's ton of info patterns , regexes here.

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if want match only if 2ndline appears @ beginning of line, this:

   boolean b = input.matches("(?is).*\\n2ndline.*"); 

or this:

 pattern p = pattern.compile("(?i)\\n2ndline", pattern.dotall);