Print only unique lines from file not the duplicates

Question

I have a sorted words list, line by line file like so:

apple
apple
grapes
lime
orange
orange
pear
pear
peach
strawberry
strawberry

I only want to print out unique lines and drop duplicates:

grapes
peach
lime

How can I do this with sed, awk or perl?

cuonglm · Answer 1 · 2016-02-09T14:55:24.713

10

That's the job for uniq:

$ LC_ALL=C uniq -u file
grapes
lime
peach

If you want other tools, like perl:

perl -nle '$h{$_}++; END {print for grep { $h{$_} == 1 } %h}' <file

edited Feb 09 '16 at 14:55

answered Feb 09 '16 at 14:45

cuonglm

Why are you using -l ? Also the for after the print is not needed if you remove the -l, because you aren't pointlessly stripping newlines. – 123 Feb 09 '16 at 15:09
1

Let us continue this discussion in chat. – cuonglm Feb 09 '16 at 15:47

Firefly · Answer 2 · 2016-02-09T15:18:56.863

1

Try this AWK!

awk '{a[$0]++} END {for (x in a) if (a[x] == 1) print x}'

edited Feb 09 '16 at 15:18

answered Feb 09 '16 at 14:40

Firefly

1

No, that still leaves the duplicate words, I want to print the only uniq words contained in the file. – Feb 09 '16 at 14:50
@MIlle82 UPS!! I hadn't understood your question!! – Firefly Feb 09 '16 at 15:20

score 1 · Answer 3 · answered Feb 09 '16 at 15:00

1

awk '{arr[$1]++} END {for (i in arr) {if (arr[i]==1) {print i} }}' 1
grapes
lime
peach

answered Feb 09 '16 at 15:00

jai_s

3 Answers3