small uniq trick

[Christos Ricudis]

Otan exete ena pelwrio arxeio ths morfhs

a
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kai 8elete na kanete kati san

cat lala.koko | sort | uniq

sas symferei perissotero na kanete

cat lala.koko | uniq | sort | uniq

H prwth uniq 8a kopsei ta repetitions sto arxiko arxeio, elafrynontas 
kata poly to baros ths sort prin to teliko uniq.

test runs (nai, giwrgo, einai epaneilhmmena runs) :

$ time cat datafile | cut -f2- -d: | uniq | sort | uniq > /dev/null

real    0m1.164s
user    0m0.712s
sys     0m0.429s

$ time cat worstcase | cut -f2- -d: |  sort | uniq > /dev/null

real    0m2.522s
user    0m1.672s
sys     0m0.782s