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gcc saying --------->undefined reference to sqrt

This is a discussion on gcc saying --------->undefined reference to sqrt within the C Programming forums, part of the General Programming Boards category; Code: #include<stdio.h> #include<math.h> void algo(int); main() { algo(5); } void algo(int k) { printf("%f",sqrt(k)); }...

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    Lightbulb gcc saying --------->undefined reference to sqrt

    Code:
    #include<stdio.h>
    #include<math.h>
    void algo(int);
    main()
    {
            algo(5);
    }
    void algo(int k)
    {
            printf("%f",sqrt(k));
    }

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    Registered User manasij7479's Avatar
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    You need to link to the math library explicitly...
    by the
    -lm
    flag for ld.
    Manasij Mukherjee | gcc-4.8.2 @Arch Linux
    Slow and Steady wins the race... if and only if :
    1.None of the other participants are fast and steady.
    2.The fast and unsteady suddenly falls asleep while running !



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    If only there was a handy readily available reference for this..........
    Quote Originally Posted by anduril462 View Post
    Now, please, for the love of all things good and holy, think about what you're doing! Don't just run around willy-nilly, coding like a drunk two-year-old....
    Quote Originally Posted by quzah View Post
    ..... Just don't be surprised when I say you aren't using standard C anymore, and as such,are off in your own little universe that I will completely disregard.
    Warning: Some or all of my posted code may be non-standard and as such should not be used and in no case looked at.

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    Quote Originally Posted by AndrewHunter View Post
    If only there was a handy readily available reference for this..........
    I think you just volunteered to write said FAQ article. I can think of one or two others that I might start writing.

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    Registered User manasij7479's Avatar
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    Quote Originally Posted by anduril462 View Post
    I think you just volunteered to write said FAQ article. I can think of one or two others that I might start writing.
    Any C++ related topic that I could volunteer to help write one ?
    Manasij Mukherjee | gcc-4.8.2 @Arch Linux
    Slow and Steady wins the race... if and only if :
    1.None of the other participants are fast and steady.
    2.The fast and unsteady suddenly falls asleep while running !



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    Here's the To Do list from the FAQ page. The one(s) that I'm considering right now are the "using multiple files in C" and the related, possibly in the same article, explanation/use of the extern keyword. Take anything else on the list that needs doing, or just write one that you feel is needed based on your experience here.

    EDIT: It looks like the FAQs haven't been touched in a while, but I don't see that as a reason to not work on them.

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    Registered User manasij7479's Avatar
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    Quote Originally Posted by anduril462 View Post
    Here's the To Do list from the FAQ page. The one(s) that I'm considering right now are the "using multiple files in C" and the related, possibly in the same article, explanation/use of the extern keyword. Take anything else on the list that needs doing, or just write one that you feel is needed based on your experience here.

    EDIT: It looks like the FAQs haven't been touched in a while, but I don't see that as a reason to not work on them.
    The sections of that list which could've been interesting for me, are unfortunately empty or already have very good "standard" links to point in answers.
    Manasij Mukherjee | gcc-4.8.2 @Arch Linux
    Slow and Steady wins the race... if and only if :
    1.None of the other participants are fast and steady.
    2.The fast and unsteady suddenly falls asleep while running !



  8. #8
    ATH0 quzah's Avatar
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    There is a new function in C99 that finds the square root of a long.
    Code:
    #define I int
    I chooseYou = sqrtl( 0xDL );
    I might be ashamed of myself if I wasn't chuckling so much.


    Quzah.
    Last edited by quzah; 08-26-2011 at 04:08 PM. Reason: #define fail, too tired
    manasij7479 likes this.
    Hope is the first step on the road to disappointment.

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    Registered User manasij7479's Avatar
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    Quote Originally Posted by quzah View Post
    There is a new function in C99 that finds the square root of a long.
    Code:
    #define int I
    I chooseYou = sqrtl( 0xDL );
    I might be ashamed of myself if I wasn't chuckling so much.

    Quzah.
    ...SO sqrtl evolved *from* something !
    Manasij Mukherjee | gcc-4.8.2 @Arch Linux
    Slow and Steady wins the race... if and only if :
    1.None of the other participants are fast and steady.
    2.The fast and unsteady suddenly falls asleep while running !



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    Quote Originally Posted by quzah View Post
    There is a new function in C99 that finds the square root of a long.
    Code:
    #define int I
    I chooseYou = sqrtl( 0xDL );
    I might be ashamed of myself if I wasn't chuckling so much.


    Quzah.
    Stop chuckling and be ashamed! That code is all kinds of broken. Your define is backwards and sqrtl takes and returns a long double, not an int. That being said, I feel like there is some sort of joke I totally didn't get...

  11. #11
    Registered User manasij7479's Avatar
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    Quote Originally Posted by anduril462 View Post
    ... I feel like there is some sort of joke I totally didn't get...
    Yes..there is..
    Watch some cartoon to find out !
    Manasij Mukherjee | gcc-4.8.2 @Arch Linux
    Slow and Steady wins the race... if and only if :
    1.None of the other participants are fast and steady.
    2.The fast and unsteady suddenly falls asleep while running !



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    Ahh, Pokemon. It was after my time, and I don't have kids yet.

    In that case, very well played Quzah. Went right over my head, but I'm short, so it happens a lot.

  13. #13
    ATH0 quzah's Avatar
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    Quote Originally Posted by anduril462 View Post
    Stop chuckling and be ashamed! That code is all kinds of broken. Your define is backwards
    Must have been not fully awake on that one.
    Quote Originally Posted by anduril462 View Post
    and sqrtl takes and returns a long double, not an int.
    I didn't even know there really was a sqrtl (it's nonstandard). I was just making a joke.
    Quote Originally Posted by anduril462 View Post
    That being said, I feel like there is some sort of joke I totally didn't get...
    That's alright, I got the joke.


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

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