CODEWITHSUNDEEP
javaregex
user2443476
user2443476

Reputation: 1975

How to indicate in a java regex, 0,1 or many times a carriage return line feed

I have 2 lines (separated by 0, 1 or many crlf), the value of the first line is always "line1", and thanks to this value I try to capture value of the second line.

Everything is working well when there is only one crlf between the 2 lines, but when there is more than one the regex is also capturing the crlf.

This is my regex : 

(?s)line1\r\n(.*?) ok

Basically I was thinking that this regex will work :

(?s)line1\r\n*(.*?) ok

But it's not, so how can i possibly indicate with the quantifier *, that there can be 0,1 or many crlf.

Thanks in advance for your help

Upvotes: 0

Views: 85

Answers (3)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626794

Regarding

how can i possibly indicate with the quantifier *, that there can be 0,1 or many crlf.

You might want to match any newline symbol sequences with [\r\n]*. This will match \r\n, \n, \r any number of times. Your regex can look like (?s)line1[\r\n]*(.*?), then.

Upvotes: 0

Duncan Jones
Duncan Jones

Reputation: 69339

You were nearly there with your pattern. You don't actually need to enable DOTALL with (?s). This pattern should suffice: 

line1(?:\r\n)*(.*)

This matches line1 followed by zero or more \r\n, then your second line.

String example = "line1\r\n\r\n\r\nline2";    
Pattern pattern = Pattern.compile("line1(?:\r\n)+(.*)");    
Matcher m = pattern.matcher(example);

if (m.find()) {
  System.out.println(m.group(1));
}

Prints: line2.

Upvotes: 2

Vyncent
Vyncent

Reputation: 1205

I would have try like this 

(?s)line1(\r\n)*(.*)

You put * on \n only so new \r\n weren't matching

Upvotes: 0

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