The production and use of dynamic library under Linux

1, the production of dynamic link library

The dynamic link library has no main function compared to a normal program. Generate. So dynamic link library files with-shared and-fpic compilation parameters. When the program calls the library function

Just link to this library.

1) write dynamic library code

Define header file reader.h

#ifndef Reader_h_ #define Reader_h_int open (char *name); int Close (char *name); #endif // Reader_h_

Writing function Body reader.c

#include <stdio.h>int open (char *name) {    printf ("%s opened.\n  ", name);     return 0 ;} int Close (char *name) {    printf ("%s closed.\n")  , name);     return 0 ;}

2) Generate Dynamic Library files

gcc -shared-fpic reader.c-o libreader.so

2, the use of dynamic library

First step: Write the test code TESTLIB.C

" Reader.h " int Main () {    char readername["81Reader";    Open (readername);    Close (readername);        return 0 ;}

Step Two: Call the Dynamic library (-L indicates the path to the dynamic-link library)

gcc testlib.c-o testlib-l./-lreader

Step three: Test output

81Reader Opened.81reader closed.

The production and use of dynamic library under Linux