grep 'is alive' log.dat > out.dat

Or if you really want to do this in Perl: 
# Assuming file name is in $ARGV[0]
while(<>){
   print if /is alive/;
}

[download]
or just

perl -ne "print if /is alive/" log.dat > out.dat

--perlplexer

In reply to Re: Printing matched lines by perlplexer
in thread Printing matched lines by zuinc

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