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Full Discussion: Shared static library
Top Forums UNIX for Dummies Questions & Answers Shared static library Post 302612825 by jim mcnamara on Monday 26th of March 2012 11:11:31 AM
Old 03-26-2012
There are static libraries - files usually in the /lib directory that end with .a.
There are shared libraries - files usually in the /lib directory that end with .so (or .sl), sometimes called dynamic libraries.

To link means 'Resolve external symbols or functions in your code like printf()'

By default, when you compile C code, you liink against a set of shared libraries.
You have to go out of your way to create an executable that is linked against a static library. Read your compiler documentation on how to do this.

There are a few valid uses for linking statically. Linking against shared libraries, also called dynamic linking, creates an executable that makes much better use of system resources, because eveybody else's executable file shares the same library with your code. MUCH less memory usage. That is why dynamic linking is better.

Got all that?

Next: LD_PRELOAD

This is an envrionment variable that anyone can set. If changes how the UNIX system looks for dynamic libraries. When you first run an executable, you have to find and open the dynamic libraries you linked against so all of the symbols like printf() will be there to use.

You use LD_PRELOAD to force the system to kind of auto-magically link against a library that was NOT one of the original linked libraries. So now the printf() function calls in your executable employ a different library with different code to execute printf.

There are limitations on LD_PRELOAD, to prevent bad guys from doing bad things, but that is beyond the scope of your question.
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LEARN ABOUT DEBIAN

sotextoutlineenabledelement

SoTextOutlineEnabledElement(3)					       Coin					    SoTextOutlineEnabledElement(3)

NAME

       SoTextOutlineEnabledElement -

       The SoTextOutlineEnabledElement class is yet to be documented.

       FIXME: write doc.

SYNOPSIS

       #include <Inventor/elements/SoTextOutlineEnabledElement.h>

       Inherits SoInt32Element.

   Public Member Functions
       virtual void init (SoState *state)
	   FIXME: write doc.
       virtual void push (SoState *state)
	   FIXME: write doc.
       virtual void pop (SoState *state, const SoElement *prevTopElement)
	   FIXME: write doc.

   Static Public Member Functions
       static SoType getClassTypeId (void)
       static int getClassStackIndex (void)
       static void * createInstance (void)
       static void initClass (void)
       static void set (SoState *const state, SoNode *const node, const SbBool enabled)
	   FIXME: write doc.
       static void set (SoState *const state, const SbBool enabled)
       static SbBool get (SoState *const state)
       static SbBool getDefault (void)

   Protected Member Functions
       virtual ~SoTextOutlineEnabledElement ()

   Additional Inherited Members
Detailed Description
       The SoTextOutlineEnabledElement class is yet to be documented.

       FIXME: write doc.

       Since:
	   Coin 1.0

	   TGS Inventor 2.4

Constructor &; Destructor Documentation
   SoTextOutlineEnabledElement::~SoTextOutlineEnabledElement (void) [protected],  [virtual]
       The destructor.

Member Function Documentation
   SoType SoTextOutlineEnabledElement::getClassTypeId (void) [static]
       This static method returns the class type.

       Reimplemented from SoInt32Element.

   int SoTextOutlineEnabledElement::getClassStackIndex (void) [static]
       This static method returns the state stack index for the class.

       Reimplemented from SoInt32Element.

   void * SoTextOutlineEnabledElement::createInstance (void) [static]
       This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

   void SoTextOutlineEnabledElement::initClass (void) [static]
       This static method initializes static data for the SoTextOutlinedEnabledElement class.

       Reimplemented from SoInt32Element.

   void SoTextOutlineEnabledElement::set (SoState *conststate, const SbBoolenabled) [static]
       FIXME: write doc.

   SbBool SoTextOutlineEnabledElement::get (SoState *conststate) [static]
       FIXME: write doc.

   SbBool SoTextOutlineEnabledElement::getDefault (void) [static]
       FIXME: write doc.

Author
       Generated automatically by Doxygen for Coin from the source code.

Version 3.1.3							  Wed May 23 2012				    SoTextOutlineEnabledElement(3)
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