|Perl: the Markov chain saw|
Re^3: grep troubleby LanX (Bishop)
|on Apr 18, 2011 at 08:30 UTC||Need Help??|
1. > But he's using grep.
Agreed, but he could copy $_ and define fall-backs for edge cases like "". (I'm not sure if he should)
If this gets more complicated he should consider using a function instead of an anonymous block.
2. > I suspect that where he showed us a literal empty string, ...
I suppose he is checking multiple log-files simultaneously for the same matching patterns. By grepping patterns, he is calculating the intersection of all patterns which apply to all files.
> those situations probably warrant a comment in real-world code
That's why I would prefer a special var $PATTERN for this behavior.
UPDATE: what bothers me is not this special behavior of a literally empty match m// but that of "If the PATTERN evaluates to the empty string". IMHO that $pat="";m/$pat/ behavior is difficult to justify.