Converting a String to Uppercase

This is a discussion on Converting a String to Uppercase within the C Programming forums, part of the General Programming Boards category; I've searched the forums, and implemented a lot of answers found here, but none of them seem to work entirely. ...

  1. #1
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    Converting a String to Uppercase

    I've searched the forums, and implemented a lot of answers found here, but none of them seem to work entirely.

    Here is the code in question:
    Code:
    #include <stdio.h>
    #include <strings.h>
    #include <string.h>
    #include <ctype.h>
    int main(int argc, char** argv)
    {
      char buf[10];
      scanf("%s", &buf);
    
      int i;
      for(i = 0; buf[i] != '\0'; i++) {
        if(buf[i] >= 'a' && buf[i] <= 'z')
          buf[i] = toupper(buf[i]);
      }
    
      printf("%s\n",buf);
    
    }
    When I run this and type "this is a test" the printout is "THIS". It only converts the first word of the string. I have tried different variations for the terminating condition of the for loop, but none of them seem to work.

    Other ways I've tried terminating the for loop:
    for( i = 0; buf[ i ]; i++ )
    for( i = 0; i < 10; i++ )

    Other way I tried changing the case of the char's:
    buf[ i ] -= 32;

    It seems to be changing the case of the char as it should, but it just stops working on the string after the first word.

    This is just a sample program, it is actually part of a project where I have a client program and a server program, and I'm sending a message to the server, where it is changed to all uppercase, then sent back to the client. This "toupper" part of the program is the only part not working. Which is why I'm working on it in a separate little test program.

  2. #2
    ATH0 quzah's Avatar
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    scanf is only reading the first "word" because that's what %s does.


    Quzah.
    Hope is the first step on the road to disappointment.

  3. #3
    CSharpener vart's Avatar
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    use fgets to read the whole line
    and islower to check the case
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  4. #4
    ATH0 quzah's Avatar
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    Better yet, don't even bother with a check, because toupper won't "up-case" things that can't be up-cased.


    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
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    scanf was the problem, thank you. Using fgets is now getting the whole line.

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