Linux build (load) dynamic library static libraries and load sample methods _linux Shell

Generation of dynamic libraries:

1,/*mysum.c*/

Copy Code code as follows:

#include <stdio.h>
#include "src.h"

int sum (int a,int b)
{
return (A+B);
}

2,/*mysum.h*/

Copy Code code as follows:

#ifndef __src_h__
#define __src_h__

int sum (int a,int b);

#endif

3,/*main.c*/

Copy Code code as follows:

#include <stdio.h>

extern int sum (int a,int b);

/*

#include <stdio.h>

#include "mysum.h"

*/

int main ()
{
int a,b,c=0;
printf ("Input A and b:\n");
scanf ("%d%d", &a,&b);
c = SUM (A,B);
printf ("c =%d\n", c);
return 0;
}

4. Generate Dynamic Library

Copy Code code as follows:

Gcc-c-fpic mysum.c mysum.h//Generate MYSUM.O file

Gcc-shared-fpic-o libmysum.so MYSUM.O//Generate dynamic library file, the default naming method is lib+ name. So

5, dynamic library static loading

Copy Code code as follows:

Gcc-o main main.c-l.-lmysum-wall

Or

Gcc-o Main Main.c-lmysum-wall

6. When executing./main, an error is reported, prompting that the Libmysum.so shared library cannot be loaded.

7, the processing method has three:

Method One:

Copy a dynamic library to/lib or/usr/lib

such as: sudo cp libmysum.so/lib

Method Two:

Changing environment variables:

Ld_library_path= $PWD Export Ld_library_path

Method Three:

Specify the path to the shared library at compile time:

Gcc-o main1-wl,-rpath,.-L.-louyang MAIN.O