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Pick a random line from a file

Terminal - Pick a random line from a file
shuf file.txt | head -n 1
2009-07-24 04:22:10
User: lxtips
Functions: head
-4
Pick a random line from a file

Alternatives

There is 1 alternative - vote for the best!

Terminal - Alternatives
shuf -n1 file.txt
sort -R file.txt | head -1
perl -e 'rand($.) < 1 && ($line = $_) while <>;'
2011-04-25 21:28:26
Functions: perl
Tags: perl knuth
1

This is from perldoc -q random.*line, which says:

This has a significant advantage in space over reading the whole file in. You can find a proof of this method in The Art of Computer Programming, Volume 2, Section 3.4.2, by Donald E. Knuth.

Who am I to argue with Don Knuth?

head -$(($RANDOM % $(wc -l < file.txt) +1 )) file.txt | tail -1
2009-07-23 12:00:49
User: sharfah
Functions: head tail wc
-4

prints a random line

Know a better way?

If you can do better, submit your command here.

What others think

Huh, shuf is in coreutils, who knew? :-)

(also note that the $RANDOM ones have the bug that $RANDOM only ranges over 32k, /usr/share/dict/words here is 98k lines...)

Comment by eichin 384 weeks and 6 days ago

Your point of view

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