dlopen

I have started using valgrind just one day ago as suggested by someone on SO itself .Its an amazing tool but today i got an issue with it.It gives the following error : definitely lost bytes but unable to tell the location of error. Here is the output of valgrind : udit@udit-Dabba ~ $ valgrind --leak-check=full sendip -v -p ipv6 -f file.txt -6s ::1 -p ah -as 0x20 -aq 0x40 -ak "yugal" -am xorauth.so -p udp -us 21 - ud 21 ::2 ==12885== Memcheck, a memory error detector ==12885== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al. ==12885== Using Valgrind-3.6.1 and LibVEX; rerun with

I am toying around with c++17 and plugins, and I have run into an error that I cannot get around. In the following MWE I can call a local function that takes a std::any , and everything works as expected when I try to read the contents. When I load this exact same function through a plugin (dlopen), it correctly sees the type on the any, but it cannot std::any_cast the contents. Any help would be greatly appreciated in figuring out what is causing this error. Here is my environment, MWE, and resulting error. >> g++ --version g++ (GCC) 7.1.1 20170526 (Red Hat 7.1.1-2) Copyright (C) 2017 Free

I have a C++ class that uses dlopen to load a library. As an exercise I was trying to dump all of the symbol names from the loaded library. I've used dlinfo to load the linkmap via RTDL_DI_LINKMAP : struct link_map { ElfW(Addr) l_addr; /* Base address shared object is loaded at. */ char *l_name; /* Absolute file name object was found in. */ ElfW(Dyn) *l_ld; /* Dynamic section of the shared object. */ struct link_map *l_next, *l_prev; /* Chain of loaded objects. */ }; This provides me a linked list of libraries that have been loaded by the dlopen call. I then thought that I could process the l

When using the dlfcn family like so: #include <stdio.h> #include <dlfcn.h> typedef int(*timefunc_t)(void*); int main() { timefunc_t fun; void* handle; handle = dlopen("libc.so.6", RTLD_LAZY); fun = (timefunc_t)dlsym(handle, "time"); printf("time=%d\n", fun(NULL)); dlclose(handle); return 0; } It causes a Memory leak: ==28803== Memcheck, a memory error detector ==28803== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al. ==28803== Using Valgrind-3.6.1 and LibVEX; rerun with -h for copyright info ==28803== Command: ./dl ==28803== time=1309249569 ==28803== ==28803== HEAP SUMMARY: =

目录 介绍 如何加载动态库 dlopen() 第一个参数: 被加载动态库的路径 第二个参数: flag表示函数符号的解析方式 dlopen 返回值 dlsym() 参数： 返回值 符号优先级 dlerror() dlclose() show code 内容学习自《 程序员的自我修养 链接装载与库》 如果只是想知道如何使用如何加载动态库和那4个函数的使用，可以直接从如何加载动态库开始看。 介绍 支持动态链接的系统往往都支持一种更加灵活的模块加载方式，叫做显式运行时链接（Explicit Run-time Linking），有时候也叫做运行时加载。也就是让程序自己在运行时控制加载指定的模块，并且可以在不需要该模块时将其卸载。从前面我们了解到的来看，如果动态链接器可以在运行时将共享模块装载进内存并且可以进行重定位等操作，那么这种运行时加载在理论上也是很容易实现的。而且一般的共享对象不需要进行任何修改就可以进行运行时装载，这种共享对象往往被叫做动态装载库（Dynamic Loading Library），其实本质上它跟一般的共享对象没什么区别，只是程序开发者使用它的角度不同。 这种运行时加载使得程序的模块组织变得很灵活，可以用来实现一些诸如插件、驱动等功能。当程序需要用到某个插件或者驱动的时候，才将相应的模块装载进来，而不需要从一开始就将他们全部装载进来，从而减少了程序启动时间和内存使用

Good evening, I'm currently working on a Plugin system in C++/Linux based on the Plux.net model. To keep it simple, I basicly declare a symbol (lets call it pluginInformation) with extern C (to unmangle) and my plugin manager look for that symbol in the pre configured imports (.so). The thing is that the main application declares the same symbol, not only that but any dependency it have may have the symbol aswell. (since in this pluginInformation, modules can publish plugs and/or slots). So when my PluginManager starts, it first try to find the symbol in the main program (passing NULL to