Javascript regex to matched group

Question

I have a multiline log file that I am attempting to parse with a regex and javascript into something more readable, I have used this question as a reference but am getting unexpected results Javascript replace with reference to matched group?.

Basically b logs "first time" undefined "second time" where I would expect to see the file name as the second match.

Here is a sample of the regex and data string that I am trying to match which results in matches. http://regex101.com/r/bW9xD4

I am trying to order the matches so that the filename is first, followed by the first time matched followed by the second time matched, can anyone point me in the right direction?

Code

var VIRTUAL = (function() {
  // Module globals
  var $ = {}; 

  // Module methods
  $ = {
    compareDelivery : function( data ) {
      var regex = new RegExp( '(\\d{2}:\\d{2}:\\d{2})|([0-9a-z]+.xml)', 'gmi' ), out = [];

      var found = data.replace(regex, function ( a, b, c ) {
          console.log(a);  

      });

      return out;
    }

  };


  return $;

}());

JSBIN: http://jsbin.com/manej/3/edit?js,console,output

You are logging `b` in the jsbin, you either want to log `a` or `b || c` — Paul S., May 23 '14 at 13:17
@PaulS. a returns time 1, filename, time 2 how can I access just the filename then the times? c is undefined, filename, undefined — KryptoniteDove, May 23 '14 at 13:19

score 1 · Answer 1 · answered May 23 '14 at 13:27

1

By looking at your data, maybe you could use a pattern like this instead

"(Time .*?)\\s(Filename .*?)\\s(Generated [^\\n]*)"

and the replaceor

function ($0, time1, file, time2) {
    // .. do stuff
}

Your current method isn't working because each match is independent to the previous one; the only reason it finds them is the g flag. The way I've suggested, the match finds all in the group at once and a g flag would make it work over multiple lines.

answered May 23 '14 at 13:27

Paul S.

64,864
9
122
138

Thanks Paul. Is there a way to modify this so that it ignores the garbage in the log and just gives me matches for the data that I can read as in my regex? – KryptoniteDove May 23 '14 at 14:01

score 1 · Accepted Answer · answered May 23 '14 at 21:50

KryptoniteDove, this simple code will do it (see the output in the online demo):

<script>
var subject = 'Time 2014-05-22T10:39:04.890117+01:00 Filename S140522DSS10002.xml::938c287eb522359b600f74bb3140bb64 Generated 2014-05-22T10:38:46.000000+01:00';
var regex = /Time.*?(\d{2}:\d{2}:\d{2}).*?([0-9a-z]*\.xml).*?(\d{2}:\d{2}:\d{2})/i;
var match = regex.exec(subject);
if (match != null) {
        document.write(match[2] + "<br>");
        document.write(match[1] + "<br>");
        document.write(match[3] + "<br>");
}
</script>

How does this work?

Instead of trying multiple matches, we match everything with a single regex, capturing the file name and the times in capture groups 1, 2 and 3.

Javascript regex to matched group

2 Answers2