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in reply to Re^5: grep for lines containg two variables
in thread grep for lines containg two variables

Right! thank you for the pointers/clarification - makes sense now!!!! and this is now valid: (?)
#!/usr/bin/perl -w # usage : ./this_script.pl input_file > captured_benchmarks use strict; use Benchmark; my @data = do { open(my $fh, '<', $0) or die; <$fh> }; timethese (1000000, { grep_and => sub{ my @res1 = grep /GGGGGACACCTTCTCTCTCT/ && /RH_MEa0001bG06/,@data; }, double_grep => sub{ my @res2 = grep /GGGGGACACCTTCTCTCTCT/,grep /RH_MEa0001bG06/,@data +; }, lookahead_grep => sub{ my @res3 = grep /^(?=.*GGGGGACACCTTCTCTCTCT)(?=.*RH_MEa0001bG06)/, +@data; } } );
because I get the following now:
Benchmark: timing 1000000 iterations of double_grep, grep_and, lookahe +ad_grep... double_grep: 11 wallclock secs ( 9.06 usr + 0.00 sys = 9.06 CPU) @ 1 +10350.92/s (n=1000000) grep_and: 8 wallclock secs ( 8.70 usr + 0.00 sys = 8.70 CPU) @ 11 +4902.91/s (n=1000000) lookahead_grep: 21 wallclock secs (20.31 usr + 0.00 sys = 20.31 CPU) +@ 49231.98/s (n=1000000)