Aho Corasick source code needed, please help

[Seth]

I am in need of source code for the Aho Corasick algorithm. I have
tried searching the web but can't seem to find any code.

Is there a good site for c code I can search?

Thanks in advance.

 

[osmium]

I am in need of source code for the Aho Corasick algorithm. I have
tried searching the web but can't seem to find any code.

Is there a good site for c code I can search?

There are useful hits, but not necessarily source code, for < aho corasick>
on Google.

 

[pete]

There are useful hits, but not necessarily source code,
for < aho corasick> on Google.

The correct way to search for code,
is to put the word "code" in your search.

http://www.google.com/search?hl=en&ie=ISO-8859-1&q=Aho+Corasick+algorithm+code

Aho Corasick algorithm code. Results 1 - 10 of about 1,100.
Search took 0.13 seconds.

http://compilers.iecc.com/comparch/article/94-06-032

 

[osmium]

The correct way to search for code,
is to put the word "code" in your search.

I wasn't *trying* to find code. The only reason I tried at all was because
I thought there might likely be a spelling error in Corasick.

 

[pete]

I wasn't *trying* to find code.

OP was.

 

[Seth]

OP was.

Thanks for the help, I checked out that code but it is all
copyrighted, which means they might as well have not even posted it as
it is useless.

Is there any source where I can get free, uncopyrighted code? Or
should I just buy a book and write the code myself? Or is that in
violation of the book's copyright?

I have read about 2 dozen papers on the subject of string matching.
Every paper is about how someone CLAIMS they can beat the AC
algorithm. No evidence is given. No proof. No source code. No
independent tests. No way for the reader to test. Just their
bragging, basically saying "mine is bigger than yours and you'll just
have to believe me."

A typical example is Mike Fisk and George Varghese and their paper
"Applying Fast String Matching to Intrusion Detection." They, of
course, claim they can beat AC, and even have some cute little graphs.
They offer no proof of this claim, of course, and no source code, no
way to test it, and no evidence they ever tested it themselves. But,
they claim they will release the code in a library. This paper was
written in 2001. Have they released the library yet? Nope. I
emailed them both, and they both ignored my request.

At best, they are useless wastes of my time that have contributed
nothing to the world of computer science other than empty brags. At
worst, they are liars.

I'm starting to think I should apply for a grant, spend the money in
Tahiti, and then write a paper claiming I can beat AC.

 

[Alan Balmer]

Thanks for the help, I checked out that code but it is all
copyrighted, which means they might as well have not even posted it as
it is useless.

Not necessarily. You can use the ideas expressed by the code, you just
have to find your own expression of those ideas. If you want to use
the code as written, or modify the code, contact the copyright holder.
They may make it available with a free license.

Is there any source where I can get free, uncopyrighted code?

No. All code is copyrighted automatically as soon as it's expressed in
tangible form (including yours;-). However, copyrighted code can be
free, depending on the wishes of the copyright holder.

Or
should I just buy a book and write the code myself? Or is that in
violation of the book's copyright?

If you use the ideas in the book and write the code yourself, there's
no violation. If you simply copy code from the book, there probably
is, depending on the terms set by the copyright holder.

 

[Mark McIntyre]

Is there any source where I can get free, uncopyrighted code?

thats 2 questions:

q1) where can I get uncopyrighted code?
a1) you can't - anything anyone writes down is copyrighted to them,
including this email, which is mostly copyrighted to me.

q2) where can I get free code?
a2) many authors make their code freely available. Its possible that
the authors you found do this too - check with them.

Or should I just buy a book and write the code myself?

that would be a better idea anyway.

Or is that in violation of the book's copyright?

if you copy enough of the book verbatim, you're breaching copyright.
"Fair use" permits you to copy reasonable extracts however.

 

[Keith Thompson]

On 4 Feb 2004 11:14:59 -0800, (e-mail address removed) (Seth) wrote: [...]

Is there any source where I can get free, uncopyrighted code?

No. All code is copyrighted automatically as soon as it's expressed in
tangible form (including yours;-). However, copyrighted code can be
free, depending on the wishes of the copyright holder.

The owner of a piece of code (or any copyrightable work) can
explicitly release it to the public domain. Such code is not covered
by copyright.

This is actually fairly rare; works don't become public domain unless
the author explicitly releases them or the copyright expires. I don't
think any C code has existed long enough for its copyright to expire.

There's a great deal of *free* code; it's covered by copyright and by
a license that explicitly allows certain uses.

One exception is Doug Gwyn's public domain Q8 library, available at
<http://www.lysator.liu.se/c/q8/>.

Disclaimer: I am not a lawyer, and this is not an appropriate forum
for discussing legal issues. I mention this only to clarify what's
already been said. Do not depend on the correctness of anything I say
about intellectual property law, other than this sentence.

 

[Mark McIntyre]

On 4 Feb 2004 11:14:59 -0800, (e-mail address removed) (Seth) wrote: [...]

Is there any source where I can get free, uncopyrighted code?

No. All code is copyrighted automatically as soon as it's expressed in
tangible form (including yours;-). However, copyrighted code can be
free, depending on the wishes of the copyright holder.

The owner of a piece of code (or any copyrightable work) can
explicitly release it to the public domain. Such code is not covered
by copyright.

I'm not sure thats quite right. You can release it to the PD, but you
still have copyright. Its an innate property of your own work.

This is actually fairly rare; works don't become public domain unless
the author explicitly releases them or the copyright expires. I don't
think any C code has existed long enough for its copyright to expire.

70 years after the author's death? Soonest would be ~2045 I guess...

 

[Keith Thompson]

On Thu, 05 Feb 2004 21:40:27 GMT, in comp.lang.c , Keith Thompson


I'm not sure thats quite right. You can release it to the PD, but you
still have copyright. Its an innate property of your own work.

I think it's right, but I could easily be mistaken. Blah blah
disclaimer blah blah.

 

[Martin Dickopp]

In the USA, yes. In most European countries, no. Not sure about the rest
of the world.

Correct.

I'm not sure thats quite right. You can release it to the PD, but you
still have copyright.

If you release a work in the public domain (assuming it's possible at
all in your jurisdiction), you give up your copyright by definition of
public domain. A work cannot simultaneously be copyrighted and in the
public domain.

Its an innate property of your own work.

In the USA, no: copyrights can be completely transfered or given up. The
European coypright tradition distiguishes between "author's rights" and
"usage rights." The latter can be transfered, sold, etc., but not the
former.

70 years after the author's death? Soonest would be ~2045 I guess...

Yes, but only in the unlikely case that this period of time (recently
extended to 90 years in the USA, retroactively covering all works that
were about to enter the public domain, BTW) will not be further extended
until then.

Martin

 

[Joona I Palaste]

In the USA, yes. In most European countries, no. Not sure about the rest
of the world.

You should see the discussion on the comp.sys.amiga.games group. People
claim that old Amiga games, no longer on the market, are abandonware,
and thus not covered by copyright. The fact that there is no such legal
status as "abandonware" does not deter them. Apparently they think that
because the concept "abandonware" has a name, it's legally recognised.

 

[osmium]

Yes, but only in the unlikely case that this period of time (recently
extended to 90 years in the USA, retroactively covering all works that
were about to enter the public domain, BTW) will not be further extended
until then.

AFAIK US copyright law is designed, and modified as necessary, so Mickey
Mouse will never lose its copyright. Mickey Mouse was born about 1928, so,
from here, it looks like anything published after 1928 will *never* lose its
copyright. Mickey Mouse seems to have a lot of friends in high places. But
one can lose copyright as a result of inattention or dying

Note that in the US there are at least three distinct sets of intellectual
property laws: trademarks, patents and copyright.

IANAL. Thank God!

 

[CBFalconer]

You should see the discussion on the comp.sys.amiga.games group.
People claim that old Amiga games, no longer on the market, are
abandonware, and thus not covered by copyright. The fact that
there is no such legal status as "abandonware" does not deter
them. Apparently they think that because the concept
"abandonware" has a name, it's legally recognised.

In practice, and until and if there is money to be made, they are
right. Once someone can make any money (net) all rights
automatically regain full force

There are people around making a living from this concept,
especially in the field of patents.

 

[Dan Pop]

On 4 Feb 2004 11:14:59 -0800, (e-mail address removed) (Seth) wrote: [...]
Is there any source where I can get free, uncopyrighted code?

No. All code is copyrighted automatically as soon as it's expressed in
tangible form (including yours;-). However, copyrighted code can be
free, depending on the wishes of the copyright holder.

The owner of a piece of code (or any copyrightable work) can
explicitly release it to the public domain. Such code is not covered
by copyright.

I'm not sure thats quite right. You can release it to the PD, but you
still have copyright. Its an innate property of your own work.

As usual, our resident idiot couldn't miss an opportunity to display his
ignorance.

Dan

 

[Alan Balmer]

On 4 Feb 2004 11:14:59 -0800, (e-mail address removed) (Seth) wrote: [...]

Is there any source where I can get free, uncopyrighted code?

No. All code is copyrighted automatically as soon as it's expressed in
tangible form (including yours;-). However, copyrighted code can be
free, depending on the wishes of the copyright holder.

The owner of a piece of code (or any copyrightable work) can
explicitly release it to the public domain. Such code is not covered
by copyright.

Correct, of course. As you say, it's rare - even people who want to
give away their software often want to control its use to some extent.

I was a bit surprised at the number of hits Google returns for "public
domain software." On investigation, many of the references turned out
not to be truly public domain, but quite a number are. Many of these
are academically produced, highly specialized programs.

 

[Mark McIntyre]

AFAIK US copyright law is designed, and modified as necessary, so Mickey
Mouse will never lose its copyright.

AFAIR copyright is actually governed by the hague convention. While
individual countries can introduce stricter laws, internationally I
can, 70 years after Walt's death, start making cartoons starring a
mouse called mickey.

 

[Joona I Palaste]

AFAIR copyright is actually governed by the hague convention. While
individual countries can introduce stricter laws, internationally I
can, 70 years after Walt's death, start making cartoons starring a
mouse called mickey.

The Disney corporation has been very dutiful in renewing its patents.
At least in the USA, "Mickey Mouse" will still belong to the Disney
corporation in 2400. That the same corporation made heaps of money
reusing children's faerytales whose own patents had expired makes this
quite ironic. Maybe those children's faerytales will soon be patented
by Disney and will require royalties to be expressed in any form?

 

[osmium]

The Disney corporation has been very dutiful in renewing its patents.
At least in the USA, "Mickey Mouse" will still belong to the Disney
corporation in 2400. That the same corporation made heaps of money
reusing children's faerytales whose own patents had expired makes this
quite ironic. Maybe those children's faerytales will soon be patented
by Disney and will require royalties to be expressed in any form?

And don't get me started on how Apple took the effort of Xerox Parc,
capitalized on that work and then sued Microsoft when *they* tried to use
the same ideas.

The Hague convention thing mentioned upstream seems to be based on the
notion that a 70 year old woman could have a child who in turns lives for 70
years. Seems unlikely to me, but even so, better than the US system, which
seems to be based on a carrot on a stick that is lengthened when necessary.