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in reply to Re: grep trouble
in thread grep trouble

Thanks davido. I guess the grep-evaluated block should look like:

{$_ eq "" or "" =~ /$_/}

(of course the actual logic in my script is different, as there are easier ways to do the above)

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Re^3: grep trouble
by LanX (Saint) on Apr 17, 2011 at 15:45 UTC
    I'm still not sure what you're trying to achieve here, cause your grep returns the PATTERNs which matched.

    Are those patterns simple words? If yes you could consider constructing an or-regex:

      DB<100> @patterns=qw#one two three#
 
  DB<101> $str="one two"
 
  DB<102> $re=join "|",@patterns
 
  DB<103> print $str =~ m/($re)/g
onetwo

    [download]

    UPDATE:

    just noticed there are still subtle differences: 

      DB<106> $str="two one two"
 
  DB<107> print $str =~ m/($re)/g
twoonetwo
  DB<108> print grep {$str=~/$_/} @patterns
onetwo

    [download]

    Cheers Rolf

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Re^3: grep trouble
by LanX (Saint) on Apr 18, 2011 at 10:37 UTC
    you also have to check for undef:

      DB<120> print scalar grep {"a"=~/$_/} ("a","",undef)
3

    [download]

    Cheers Rolf

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