sed '1000000!d;q' < massive-log-file.log

Efficiently print a line deep in a huge log file

Sed stops parsing at the match and so is much more effecient than piping head into tail or similar. Grab a line range using sed '999995,1000005!d' < my_massive_file

21
By: root
2009-01-26 11:50:00

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What Others Think

I prefer: sed -n '1000000p' massive-log-file.log
penthief · 472 weeks and 5 days ago
Have you done tests? In my examples (line 10 mio from a 19 mio lines file) head|tail was faster. sed was only slightly faster if you write: head -n 10000001 | tail -n 2 0.9 sec utime, 2 sec clock time sed -n '10000000,10000001p' 1.7 sec utime, 2.2 sec clock time sed -n '10000000,10000001p;10000002q' 0.9 sec utime, 1.2 sec clock time Otherwise sed will parse until the end, what head|tail doesn't. Overall the time differences seem irrelevant. It's more a question of beauty. :-)
weidenrinde · 131 weeks ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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