count.c:
#include<stdio.h>
int count=100;
void set(int v){
?? ?count = v;
}
void get(){
?? ?printf("count:%d\n", count);
}
gcc -o count.so count.c -shared -fPIC
main.c:
#include <stdio.h>
#include <dlfcn.h>
void case1(){
?? ?void *handler = dlopen("./count.so", RTLD_LAZY);
?? ?if (handler == NULL){
?? ??? ?printf("ERROR:handler\n");
?? ??? ?return;
?? ?}
?? ?void (*get)() = (void (*)())dlsym(handler, "get");
?? ?void (*set)(int v) = (void (*)(int v))dlsym(handler, "set");
?? ?if (get == NULL){
?? ??? ?printf("ERROR:get\n");
?? ??? ?return;
?? ?}
?? ?if (set == NULL){
?? ??? ?printf("ERROR:set\n");
?? ??? ?return;
?? ?}
?? ?get();
?? ?set(666);
?? ?get();
?? ?//dlclose(handler);
?? ?return;
}
void case2(){
?? ?void *handler = dlopen("./count.so", RTLD_LAZY);
?? ?if (handler == NULL){
?? ??? ?printf("ERROR:handler\n");
?? ??? ?return;
?? ?}
?? ?void (*get)() = (void (*)())dlsym(handler, "get");
?? ?void (*set)(int v) = (void (*)(int v))dlsym(handler, "set");
?? ?if (get == NULL){
?? ??? ?printf("ERROR:get\n");
?? ??? ?return;
?? ?}
?? ?if (set == NULL){
?? ??? ?printf("ERROR:set\n");
?? ??? ?return;
?? ?}
?? ?get();
?? ?set(666);
?? ?get();
?? ?//dlclose(handler);
?? ?return;
}
void main(){
?? ?case1();
?? ?case2();
}
gcc main.c -ldl
./a.out
count:100
count:666
count:666
count:666
