formating file contents

[unmlobo]

I have a file that has data in the format below. Is there a way for me to have the system see that user2 is the same as the other user2 and delete one of them. I'm trying to weed out dups. I think this would be a sed or awk script which I'm not familar with. Thanks all!

user1 pts/23 Jan 29 14:24 (1.1.1.1)
user2 pts/23 Jan 29 08:52 (2.2.2.2)
user2 pts/23 Jan 29 08:52 (2.2.2.2)
user3 pts/20 Jan 29 13:08 (3.3.3.3)
user3 pts/20 Jan 29 13:08 (3.3.3.3)
user4 pts/34 Jan 29 13:39 (4.4.4.4)
user4 pts/34 Jan 29 13:39 (4.4.4.4)
user5 pts/4 Jan 29 09:57 (5.5.5.5)
user5 pts/4 Jan 29 09:57 (5.5.5.5)

 

[Salem]

sort -u file > newfile

would remove identical entries from a file.

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[unmlobo]

Thanks a million Salem!

 

[KenCunningham]

Also man uniq if the repeated lines are always adjacent.