Re: bug report - uniq

[Eric Blake]

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According to Jiusheng Chen on 12/16/2007 11:13 PM:
> Hello,
> 
> Can someone explain why the following happens?
> 
> address@hidden:~/DE_COUNT/loser_percentage_analysis/mysql_outputs$ uniq 
> test_uniq
> 106996516444209225
> 1
> 106996516444209225
> 1

Not a bug.  Reread 'uniq --help', in particular, the bit about:

| Discard all but one of successive identical lines from INPUT (or
| standard input), writing to OUTPUT (or standard output).

If your file is not sorted beforehand, then uniq is not going to sort it
either.  You may be interested in 'sort -u'.

As an aside, I'm wondering if the --help output for uniq should be a bit
more explicit about this property; contrast it with the output for join,
which states:
|Important: FILE1 and FILE2 must be sorted on the join fields.
|E.g., use `sort -k 1b,1' if `join' has no options.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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