Re: removing duplicates

From: "John W. Krahn" <krahnj@xxxxxxxxx>
Jenda Krynicky wrote:
From: "John W. Krahn" <krahnj@xxxxxxxxx>
Rob Dixon wrote:
obdulio santana wrote:
May be this helps

perl -lne "print if ++$D{$_} == 1" address.txt
You may prefer the cuteness of

perl -lne "print unless $D{$_}++" address.txt
Or the shortness of:

perl -ne'$D{$_}++||print' address.txt

Actually this

perl -n'${$_}||=print'

works as well as long as the last line in the file either does end
with a newline or doesn't match any builtin variable whose default
value is already true.

One more keystroke down.

$ perl -c -n'$D{$_}++||print'
Unrecognized switch: -$D{$_}++||print (-h will show valid options).

Sorry, it should have been

perl -ne'${$_}||=print'

I'm using windows so I have to test it with doublequotes in place of
the singlequotes so I must have made a mistake changing them back.


From: "Chas. Owens" <chas.owens@xxxxxxxxx>
That is nasty. If I am reading that correctly you are using a
symbolic reference to create variables with the name of the line. > I can't remember, does Perl have a limit on the size of a variable > name?

Yes, you are reading it correctly. And since the line contains the
newline it can't match any builtin. Except possibly for the last line
in the file.

Does it have a limit on the size of a hash key?

If it does, then the limit is high enough I believe.

Jenda


===== Jenda@xxxxxxxxxxx === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
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