strcmp, a problem with capital letters

This is a discussion on strcmp, a problem with capital letters within the C Programming forums, part of the General Programming Boards category; Hey all, I'm basically in the process of sorting words in a text file. As it currently stands everything is ...

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    strcmp, a problem with capital letters

    Hey all,

    I'm basically in the process of sorting words in a text file. As it currently stands everything is working, however it seems that words beginning with a capital letter are placed before lowercase letters, regardless of their position in the alphabet (I'm guessing this is because of the byte size).

    Was just wondering if there were any easy solutions available? I'm guessing the easiest alternative would be to make all the words lower or upper cases, but after searching google and trying strlwr and tolower, neither of the functions worked

    Any help welcome,
    Thanks.

  2. #2
    and the hat of wrongness Salem's Avatar
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    You might have a non-portable stricmp() or strcasecmp() or something along those lines.

    Or you have to write your own equivalent, using say tolower() on each char you compare.
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    if everything was working then you wouldnt have a problem right?

    are you only using 'strcmp' to compare the strings? do you realize that: 'A' < 'a'? refer to the ASCII table for more info on that.

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    Quote Originally Posted by Salem View Post
    You might have a non-portable stricmp() or strcasecmp() or something along those lines.
    hmm, I tried changing strcmp() to strcasecmp() and got the same output.
    Quote Originally Posted by Salen View Post
    Or you have to write your own equivalent, using say tolower() on each char you compare.
    I attempted to make my own but didn't get very far, heh. The tolower() I referred to was something I found whilst searching google.

    Quote Originally Posted by nadroj
    if everything was working then you wouldnt have a problem right?
    True
    Quote Originally Posted by nadroj
    are you only using 'strcmp' to compare the strings? do you realize that: 'A' < 'a'? refer to the ASCII table for more info on that.
    I'm currently using strcmp() yes. I'm aware that 'A' < 'a' with regards to binary, but was under the impression that strcmp() would compensate for the correction in general English (e.g 'B' > 'a').

    Is there a function that can permanently convert a string to lower case?

    -Update
    Apologies Salem, it seems that I hadn't fully changed my strcmp() to strcasecmp(). The program is now 'working as intended'.
    Many thanks
    Last edited by RichardH; 04-22-2007 at 01:07 PM.

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    C++ Witch laserlight's Avatar
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    No, but as Salem mentioned you can use tolower(), which works on characters, to write a function to convert strings to lowercase.
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    Quote Originally Posted by laserlight View Post
    No, but as Salem mentioned you can use tolower(), which works on characters, to write a function to convert strings to lowercase.
    ah, good to know for future reference, thanks

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    Registered User Noir's Avatar
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    I'm aware that 'A' < 'a' with regards to binary, but was under the impression that strcmp() would compensate for the correction in general English (e.g 'B' > 'a').
    strcmp() does a lexigraphical comparison, not an alphabetical comparison. If you want it to compensate, you have to write your own function that does it.
    Is there a function that can permanently convert a string to lower case?
    Yes, you can check your compiler for _strlwr or something like that. Most compilers will have a comparable function that converts a string to lower case. But according to people here, you have to write your own portable function because anything nonportable is evil and anyone who suggests using something nonportable is stupid. At least this time it's easy:
    Code:
    char *strLower( char *str ) {
      char *temp;
    
      for ( temp = str; *temp; temp++ ) {
        *temp = tolower( *temp );
      }
    
      return str;
    }

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    C++ Witch laserlight's Avatar
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    But according to people here, you have to write your own portable function because anything nonportable is evil and anyone who suggests using something nonportable is stupid.
    Well, you could wrap the unportable function such that it can be easily switched for something else when ported elsewhere.
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    Registered User Noir's Avatar
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    I could, but I get jumped on even if I write something portable that someone doesn't like. So I'll just hedge my bets and hope my style isn't nitpicked.

  10. #10
    ATH0 quzah's Avatar
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    You're just being whiny. The reason I try to use portable code is because then we don't have to worry about someone coming along later and saying "This doesn't work for me!", hopefully avoiding hundreds of threads on the exact same topic and problem.


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  11. #11
    Registered User Noir's Avatar
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    You're just being whiny.
    Yeah, I know. The way I see it, all I can do is have fun with it. You guys expect me to be perfect according to your standards, but your standards are impossible to predict and it's impossible to be perfect. So if I'm going to get flamed in public and in private no matter what I do, I'll at least enjoy myself.

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    ATH0 quzah's Avatar
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    I don't expect you to be anything. You worry too much. The fact is I just don't give a damn how you are. If I feel like commenting on something, I do. If I don't, I don't. But now we're way off track of this thread.


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