Thread: Help using header files in C

  1. #1
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    Help using header files in C

    Hello. I'm using gcc under linux and i'd like to know if they're any guides on the net to show how to use the functions within the header files so you can use them in your program without any errors and ensure you've understood what the function requires.

    Thanks

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    Essentially, the guideline is that you put a function prototype in the header file, along with any structure or type definitions that the code using the function may need.

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    Mats
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  3. #3
    and the Hat of Guessing tabstop's Avatar
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    Or if you mean the system functions, you type "man" and then the name of the function.

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    Quote Originally Posted by tabstop View Post
    Or if you mean the system functions, you type "man" and then the name of the function.
    Ok cool :-D. Are the manual pages very useful then when programming and are they reliable in the sense there're hundreds of files tell you how to use the linux functions in C?

  5. #5
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    man pages are definitely useful and meaningful, and generally reliable - the commonly used functions don't change much, so you they are unlikely to be out of date.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  6. #6
    spurious conceit MK27's Avatar
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    You should also download The GNU C Library Reference Manual since they are the ones who built gcc and your c library. It's often the same as the man pages but may contain more information and is easier to follow in its presentation.

    b/t/w to use string functions:

    Code:
    #include <string.h>
    etc.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  7. #7
    Registered User slingerland3g's Avatar
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    In addition to what has been mentioned. I would recommend reviewing how other programs have incorporated these ".h" files and see how they handled these prototype definitions. That would be a good start. Learn by example I always think.... Using .h files leads to more portable and "reuse" code techniques and ideal for creating or enhancing new ADT's. But creating new ADTs would be another subject once you get past how and when to make use of header files.

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