LinuxQuestions.org - How to create shared objects and how are they useful

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How to create shared objects and how are they useful

hi all,
i want to create a .so of myfile.c,
then dynamically while program is running,
i want this .so to be linked or unlinked as per needs.
Is there any way do to this.
Please help me as soon as possible.
thanks in advance.

this forum is primarrly for saying hi,
thsi woudl be better suited in the programming forum

Moved: This thread is more suitable in Programming and has been moved accordingly to help your thread/question get the exposure it deserves.

Look at
http://tldp.org/HOWTO/Program-Library-HOWTO/

Especially the section on dlopen and dlclose

Is the question also included 'how to create dynamic link library'? If so, this is answer.
To create share library or dynamic link library do as follow.
I also include description taking from 'man gcc' for time-saving too.

Create ddl:

Code:

#gcc -c -fPIC mydev.c -o mydev.o

#gcc -shared libmydev.so mydev.o

Create executable file (linking with ddl)

Code:

#gcc mynewdev.c libmydev.so

Then when you take your program to run on other machines make sure you copy *.so file to /lib/ or /usr/lib too.

Ref

Quote:

-fPIC
If supported for the target machine, emit position-independent
code, suitable for dynamic linking and avoiding any limit on the
size of the global offset table. This option makes a difference
on the m68k and the SPARC.

Position-independent code requires special support, and therefore
works only on certain machines.

I think you already know how to create static library but I will included to this post for another may find it useful.

Create static link library:

Code:

#gcc -c mydev.c -o mydev.o

#ar rcs libmydev.a mydev.o

Create executable file (linking with static):

Code:

#gcc -static mynewdev.c -lmydev