GCC make static library and dynamic Library summary

making static libraries and dynamic libraries under Linux

Directory structure:

File contents:

Main.c
#include <stdio.h>
#include ". /include/add.h "
int main ()
{
    printf ("%d ", add (1,2));
____________________________________________
//add.c
#include ". /include/add.h '
int Add (int a, int  b)
{return
    a+b;   
}
______________________________________________
//add.h
int Add (int a, int  b)

Dynamic Library production (. So)

Gcc-shared-fpic-o lib/libadd.so SRC/ADD.C

or

Gcc-fpic-c src/add.c    
Gcc-shared-o libadd.so  

using shared libraries

GCC Src/main.c-llib-ladd-o Main                                                                                    

Run an error:

./main:error while loading shared libraries:libadd.so:cannot open Shared object file:no such file or directory

Solution Summary :
1. Add-wl and Rpath

2. Modify Ld_library_path

Export Ld_library_path=~/test/lib: $LD _library_path

3. Use Ldconfig

Put the library on the standard path
CP ~/test/lib/libadd.so/usr/lib
chmod 0775/usr/lib/libadd.so
/update cache
ldconfig
gcc Src/main.c-llib-ladd-o Main       

-fpic: Compiling a dynamic library must, output the code that does not depend on the location
-shared: Compile dynamic library must options
-wi: Pass some parameters to the linker static library production

Gcc-c src/add.c-o ADD.O           //Make obj file
ar-crv lib/libadd.a add.o          //Archive file
gcc src/main.c-llib-ladd-o ma In  //plus L (indicates link directory) L (indicates link library name)