$ uname -a CYGWIN_NT-10.0-19045 titan 3.4.10-1.x86_64 2023-11-29 12:12 UTC x86_64 Cygwin #### $ perlbrew list * perl-5.39.3 perl-5.38.0 perl-5.36.0 perl-5.34.0 perl-5.33.5 perl-5.32.0 perl-5.30.0 #### $ perl -E 'my $test_rec = "X" x 45; open my $fh, ">", "test_data"; $fh->say($test_rec) for 1..769114;' $ ls -l test_data -rw-r--r-- 1 ken None 35379244 Jan 23 17:09 test_data $ wc test_data 769114 769114 35379244 test_data $ head -1 test_data XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX #### $ perl -E 'my $test_rec = "Query" . "X" x 40; open my $fh, ">", "test_data_Q"; $fh->say($test_rec) for 1..769114;' $ ls -l test_data_Q -rw-r--r-- 1 ken None 35379244 Jan 23 17:23 test_data_Q $ wc test_data_Q 769114 769114 35379244 test_data_Q $ head -1 test_data_Q QueryXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX #### $ perl -v | head -2 | tail -1 This is perl 5, version 39, subversion 3 (v5.39.3) built for cygwin-thread-multi $ ./op_code.pl test_data 0.111368 read lines from disk and do RE. 0.096441 read lines from in-memory file and do RE. $ ./op_code.pl test_data_Q 0.356852 read lines from disk and do RE. 398.759730 read lines from in-memory file and do RE. #### $ perl -v | head -2 | tail -1 This is perl 5, version 36, subversion 0 (v5.36.0) built for cygwin-thread-multi $ ./op_code.pl test_data 0.118364 read lines from disk and do RE. 0.094379 read lines from in-memory file and do RE. $ ./op_code.pl test_data_Q 0.362871 read lines from disk and do RE. 399.115542 read lines from in-memory file and do RE. #### $ perl -v | head -2 | tail -1 This is perl 5, version 30, subversion 0 (v5.30.0) built for cygwin-thread-multi $ ./op_code.pl test_data 0.112352 read lines from disk and do RE. 0.096379 read lines from in-memory file and do RE. $ ./op_code.pl test_data_Q 0.327187 read lines from disk and do RE. 398.730810 read lines from in-memory file and do RE.