long NSString to unique shorter string

Question

I have a long NSString like that;

[NSString stringWithFormat:@"st=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&max=10"];

It is too long and i should make it shorter. It must me unique with its original string. Any idea?

Thanks;

it is a url to get some data. and i'll use this parameter string to generate cache file. beacuse it is too long, ios do not let me to use it as a file name. — serhats, Aug 06 '12 at 10:10

score 2 · Accepted Answer · answered Aug 06 '12 at 11:45

2

this blog is a good solution of my question.

http://mobiledevelopertips.com/core-services/create-md5-hash-from-nsstring-nsdata-or-file.html

answered Aug 06 '12 at 11:45

serhats

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MD5 hashes created from a string are not guaranteed to be unique. – Shaun Budhram Oct 05 '13 at 00:51

score 1 · Answer 2 · answered Aug 06 '12 at 10:58

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If you don't want to retrieve the string later, you can hash it with, for example, SHA1 (have a look at Apple's CommonCrypto library).

answered Aug 06 '12 at 10:58

score 0 · Answer 3 · edited May 23 '17 at 12:12

I don't work with iphone or objective c, but this seems like you could use something like a hashmap or a dictionary - value being the shortened string (cache file name), or whatever, and key being your long url. I guess there's some data structure available in objective c/iOS for this purposes...
Also, have a look at this question.
It might not be a good idea to use really long strings for dictionary keys, it's usually the other way around: keys are short, value holds arbitrary data.

score 0 · Answer 4 · answered Aug 06 '12 at 11:33

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There are some wrapper classes used for shortening URLs like MKBitlyHelper.Using this class you can shorten your url and then use it further.You can get it from here http://blog.mugunthkumar.com/coding/bit-ly-wrapper-objective-c-iphone/

answered Aug 06 '12 at 11:33

AJS

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long NSString to unique shorter string

4 Answers4