Hello anyone knows how to write a funtion to genereate a tiny url with
letters and numbers only. Something almost always unique. THanks.
letters and numbers only. Something almost always unique. THanks.
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Re: hash from long url to short url
"joe" <jcharth@gmail. comwrote in message
news:af9ad0f2-7db0-476f-b14f-6697b9f2cf27@m2 3g2000hsc.googl egroups.com...It's inherently impossible to collapse 36^N unique URLs to 36^(N/4) uniqueHello anyone knows how to write a funtion to genereate a tiny url with
letters and numbers only. Something almost always unique. THanks.
>
tiny urls.
However there's a hash function on my websites. It's in one of the free
chapters under Basic Algorithms. I recommend that you split the string into
2, and generate 2 unsigned longs. The chance of a collision is so low as to
be negligible. Then use the modulus operation to reduce to alpahanumeric.
--
Free games and programming goodies.
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Re: hash from long url to short url
Malcolm McLean wrote:
news:af9ad0f2-7db0-476f-b14f-6697b9f2cf27@m2 3g2000hsc.googl egroups.com...>
"joe" <jcharth@gmail. comwrote in message
>Also a Google search seems to show up a lot of TinyURL generators thoughIt's inherently impossible to collapse 36^N unique URLs to 36^(N/4)>Hello anyone knows how to write a funtion to genereate a tiny url
>with letters and numbers only. Something almost always unique.
>THanks.
>>
unique tiny urls.
However there's a hash function on my websites. It's in one of the
free chapters under Basic Algorithms. I recommend that you split the
string into 2, and generate 2 unsigned longs. The chance of a
collision is so low as to be negligible. Then use the modulus
operation to reduce to alpahanumeric.
not, AFAICS, in C. Maybe the OP can study the code and rewrite it in C.
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Re: hash from long url to short url
"Malcolm McLean" <regniztar@btin ternet.comwrite s:
I have a feeling this is a bad idea[1]. The Bernstein hash function"joe" <jcharth@gmail. comwrote in message
news:af9ad0f2-7db0-476f-b14f-6697b9f2cf27@m2 3g2000hsc.googl egroups.com...It's inherently impossible to collapse 36^N unique URLs to 36^(N/4)>Hello anyone knows how to write a funtion to genereate a tiny url with
>letters and numbers only. Something almost always unique. THanks.
>>
unique tiny urls.
However there's a hash function on my websites. It's in one of the
free chapters under Basic Algorithms. I recommend that you split the
string into 2, and generate 2 unsigned longs. The chance of a
collision is so low as to be negligible.
(which is the one on your) site uses unsigned long but will work just
as well with any unsigned integer type. If the OP has access to
longer integers, it seems safer to simply use a longer integer that
than generate two hashes from two parts of the string.
[1] I have no formal argument in support of this, just the feeling
that, since URLs often have similar parts you are wasting the hash
function's mixing ability if you split the string. Anyway, even if
there is no reason to worry here, why take the risk -- unless, of
course, you don't have longer integer types.
--
Ben.
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Re: hash from long url to short url
"Ben Bacarisse" <ben.usenet@bsb .me.ukwrote in messageYou might well be right. If two URLs share the same introduction, which isI have a feeling this is a bad idea[1]. The Bernstein hash function
(which is the one on your) site uses unsigned long but will work just
as well with any unsigned integer type. If the OP has access to
longer integers, it seems safer to simply use a longer integer that
than generate two hashes from two parts of the string.
>
[1] I have no formal argument in support of this, just the feeling
that, since URLs often have similar parts you are wasting the hash
function's mixing ability if you split the string. Anyway, even if
there is no reason to worry here, why take the risk -- unless, of
course, you don't have longer integer types.
>
extremely plausible, then effectively you are wasting a long.
--
Free games and programming goodies.
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Re: hash from long url to short url
joe wrote:Yes. No. You're welcome.>
Hello anyone knows how to write a funtion to genereate a tiny url with
letters and numbers only. Something almost always unique. THanks.
--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home .att.net>
Try the download section.
--
Posted via a free Usenet account from http://www.teranews.com
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Re: hash from long url to short url
May be i could get the char value of each letter multiply it by the
position in the string and come up with a number. Just an idea.
On Feb 22, 2:31 pm, CBFalconer <cbfalco...@yah oo.comwrote:joe wrote:
>>Hello anyone knows how to write a funtion to genereate a tiny url with
letters and numbers only. Something almost always unique. THanks.
Yes. No. You're welcome.
>
--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home .att.net>
Try the download section.
>
--
Posted via a free Usenet account fromhttp://www.teranews.co mComment
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Re: hash from long url to short url
Malcolm McLean wrote, On 22/02/08 15:23:There is also a significant possibility of two URLs sharing a>
"Ben Bacarisse" <ben.usenet@bsb .me.ukwrote in messageYou might well be right. If two URLs share the same introduction, which>I have a feeling this is a bad idea[1]. The Bernstein hash function
>(which is the one on your) site uses unsigned long but will work just
>as well with any unsigned integer type. If the OP has access to
>longer integers, it seems safer to simply use a longer integer that
>than generate two hashes from two parts of the string.
>>
>[1] I have no formal argument in support of this, just the feeling
>that, since URLs often have similar parts you are wasting the hash
>function's mixing ability if you split the string. Anyway, even if
>there is no reason to worry here, why take the risk -- unless, of
>course, you don't have longer integer types.
>>
is extremely plausible, then effectively you are wasting a long.
significant tail. E.g.
--
Flash Gordon
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Re: hash from long url to short url - TPA
joe wrote:
Please don't top-post. Your replies belong following or interspersedMay be i could get the char value of each letter multiply it by the
position in the string and come up with a number. Just an idea.
with properly trimmed quotes. See the majority of other posts in the
newsgroup, or:
<http://www.caliburn.nl/topposting.html >
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Re: hash from long url to short url
joe <jcharth@gmail. comwrites:
Hello anyone knows how to write a funtion to genereate a tiny url with
letters and numbers only. Something almost always unique. THanks.[Top posting corrected]. That is one way, but there has been a lot ofMay be i could get the char value of each letter multiply it by the
position in the string and come up with a number. Just an idea.
study of how to turn a string into a number and your method has no
particular advantage over others that have been found to be useful.
The advice you've had to use a known hash function is good advice.
--
Ben.
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Re: hash from long url to short url - TPA
"Default User" <defaultuserbr@ yahoo.comwrites :
CBFalconer and Default User actively contributing to CLC in their ownjoe wrote:
>>>May be i could get the char value of each letter multiply it by the
>position in the string and come up with a number. Just an idea.
Please don't top-post. Your replies belong following or interspersed
with properly trimmed quotes. See the majority of other posts in the
newsgroup, or:
<http://www.caliburn.nl/topposting.html >
inimitable manner again. Nice.
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Re: hash from long url to short url - TPA
On 23 Feb 2008 at 20:37, Richard wrote:Yes - with "contributo rs" like these, who needs trolls?"Default User" <defaultuserbr@ yahoo.comwrites :
>>>joe wrote:
>>>>>>May be i could get the char value of each letter multiply it by the
>>position in the string and come up with a number. Just an idea.
>Please don't top-post. Your replies belong following or interspersed
>with properly trimmed quotes. See the majority of other posts in the
>newsgroup, or:
><http://www.caliburn.nl/topposting.html >
CBFalconer and Default User actively contributing to CLC in their own
inimitable manner again. Nice.
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