Printing part of a local variable

This is a discussion on Printing part of a local variable within the C Programming forums, part of the General Programming Boards category; Hello, I was wondering if there is a way to only get a certain part of text from a variable. ...

  1. #1
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    Printing part of a local variable

    Hello,

    I was wondering if there is a way to only get a certain part of text from a variable. For example if y = hello hey sup howdy, is there any easy way to choose and print one of those varialbes? Thanks!

  2. #2
    kiddo
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    i dint get u. can u elaborate on it.

  3. #3
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    ok,

    I have a varialbe that is the following:

    y = -1 hello hey sup -2 bye cya

    Is there a way that I can get it to print everything except everything after -2?

  4. #4
    and the hat of int overfl Salem's Avatar
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    Sure, you can use strstr() to find the bits of strings which interest you.

    Code:
    char test[] = "this is a message";
    char *p = strstr( test, "mess" );
    if ( p != NULL ) {
      len = p - test;
      printf( "%.*s\n", len, test );
    }
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
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    Thats almost what I need, Salem. But how would I want to include everything [I]after[I] "message"?

  6. #6
    and the hat of int overfl Salem's Avatar
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    printf("%s",p) ?
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  7. #7
    Frequently Quite Prolix dwks's Avatar
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    Probably more like
    Code:
    printf("%s", p+strlen("message "));
    dwk

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  8. #8
    Registered User cbastard's Avatar
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    Quote Originally Posted by dwks
    Probably more like
    Code:
    printf("%s", p+strlen("message "));
    may be this,just a matter of space .
    printf("%s", p+strlen("message"));

  9. #9
    Frequently Quite Prolix dwks's Avatar
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    No, since your way would print a space in front of p.
    dwk

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    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
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  10. #10
    Registered User cbastard's Avatar
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    c compiler ignores white spaces like , p.but strlen will give 1 more character for space in string.so i think ur will eat a character after message

  11. #11
    Frequently Quite Prolix dwks's Avatar
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    c compiler ignores white spaces . . .
    It does, but not in strings. Check a binary dump if you like (or use gcc -S).
    strlen will give 1 more character for space in string.so i think ur will eat a character after message
    Not if the message is
    Code:
    "this is the message and a long one at that"
    Then your code would produce a pointer to a string that looks like this:
    Code:
    " and a long one at that"
    Wheras mine would point to
    Code:
    "and a long one at that"
    Do you see?
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
    "The only real mistake is the one from which we learn nothing." -- John Powell


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