[olug] sort -u vs uniq

Noel Leistad noel at metc.net
Mon Mar 13 10:23:13 CDT 2017

I'm trying to get a list of uniq IP addresses from a log file. I have a 
list of ALL IP addresses. Using sort -nu and sort -n | uniq give me 2 
different lists.

A stare and compare make me think that sort -nu  only considers the 
first 2 octets as significant. RTFM of the sort man page indicates sort 
honors LC_COLLATE.

<appear uninformed>
LC_COLLATE isn't in env, so I'm assuming it's set at build/compile time 
when building sort or in the c libraries someplace?
</appear uninformed -- hardly, stupid probably better tag... and not 

Could this be why the sort -u and uniq return differing output? I don't 
see anyplace to specify "how much" to consider significant when running 
sort. Anyone care to offer thoughts?



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