Grok fails to parse single digit patterns when used as part of other patterns

[greg wegman]

I've run into a bug when using grok for dates. I'm not sure how to work around it, but it keeps resulting in _grokparsefailure.

Pattern for Date:

****************************************************************
* Essentially MONTHDAY is what breaks the Pattern, I've also tried other patterns but nothing works
* ([1-9]|0[1-9]|[12][0-9]|3[01])... even [1-9] alone results in failure
****************************************************************
MONTHDAY (?:(?:0[1-9])|(?:[12][0-9])|(?:3[01])|[1-9])

TOMCATDATE %{MONTH} %{MONTHDAY}, %{YEAR} %{HOUR}:%{MINUTE}:%{SECOND}(AM|PM)

Sample Input:
1) Jun 4, 2013 12:25:33 AM org.apache.catalina.core.ApplicationContext log 1
2) Jun 14, 2013 12:25:33 AM org.apache.catalina.core.ApplicationContext log 2
3) June 4, 2013 12:25:33 AM org.apache.catalina.core.ApplicationContext log 3
4) June 04, 2013 12:25:33 AM org.apache.catalina.core.ApplicationContext log 3

Sample Output:
1) _grokparsefailure
2) SUCCESS
3) _grokparsefailure
4) SUCCESS

If you could look into this bug, I'd really appreciate it. Thanks

[Alex Garel (alex-garel)]

I think you are not in the right project. This is grok the framework based on ztk http://grok.zope.org/
not https://code.google.com/p/semicomplete/wiki/Grok.