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fscanf() and reading a file ,which has unknown line , line by line

This is a discussion on fscanf() and reading a file ,which has unknown line , line by line within the C Programming forums, part of the General Programming Boards category; hi guys a have a problem with my homework.I need to read a file line by line with fscanf() but ...

  1. #1
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    fscanf() and reading a file ,which has unknown line , line by line

    hi guys a have a problem with my homework.I need to read a file line by line with fscanf() but i couldnt do it . the content of the file is as shown:
    Madrid Rome 300
    Prague Paris 500
    Istanbul Rome 350
    Paris Rome 600
    .
    .
    .

    And i need to read line by line. how could i do it ? but i'm not allowed to use static arrays ?

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    I don't really know what you mean by line by line but maybe you can look every char unetil you find \n .
    Last edited by dekl; 06-06-2012 at 02:26 PM.

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    Quote Originally Posted by dekl View Post
    I don't really know what you mean by line by line but maybe you can look every char unetil you find \n .
    I've though i know but ı couldnt do it .

    here is my code
    Code:
    
    while (fscanf(ifp,"%s %s %d",city1,city2,distance) != EOF) {
      
    }
    printf("%s",city1);
      printf("\n");
      printf("%s",city2);
      printf("\n");
    but it gives me city1=600 and city2=Rome instead of madrid and rome .where ı am wrong ?

  4. #4
    Registered User hk_mp5kpdw's Avatar
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    What do you need to do with the data you read? Do you need to store it or do some type of processing on it?

    [edit]You probably need to use the address of operator (&) to store into the distance variable.[/edit]

    [edit2]You probably want the print commands to be inside the loop, not outside of it.[/edit2]
    Last edited by hk_mp5kpdw; 06-06-2012 at 02:32 PM.
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    I've tried to make shortest path algorithm and i need to read cities and distances between them from a file .

    and you are right ,I forgot the &
    Last edited by dayanike; 06-06-2012 at 02:35 PM.

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    Quote Originally Posted by hk_mp5kpdw View Post
    [edit2]You probably want the print commands to be inside the loop, not outside of it.[/edit2]
    Did you heed this advice? "Madrid" and "Rome" are stored during the first iteration of the "while" loop, but are overwritten during subsequent iterations. And nothing is printed until the loop is complete. This might also highlight where your data read gets fluky.

  7. #7
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    Well, for what its worth, you can try to finish the format argument with "\n" to read it line by line. It just tells the function to eat an End-of-Line character and then continue (if it is in a loop)...

    Don't you just hate homework. I am stuck at a similar thing, but with the actual file I/O...
    dekl likes this.

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