c++ - 使用 seasocks echo 服务器构建错误

Question

我正在尝试使用 C++ 中的 seasocks 构建一个简单的回显服务。我已经将 seasocks 编译并安装到/usr/local/* 中，看起来这些库包含得很好，但是我在启动服务器时遇到错误。

这是我正在使用的示例:

    #include "seasocks/PrintfLogger.h"
    #include "seasocks/Server.h"
    #include "seasocks/StringUtil.h"
    #include "seasocks/WebSocket.h"

    #include <cstring>
    #include <iostream>
    #include <memory>
    #include <set>
    #include <sstream>
    #include <string>

    /* Simple server that echo any text or binary WebSocket messages back. */

    using namespace seasocks;

    class EchoHandler: public WebSocket::Handler {
    public:
        virtual void onConnect(WebSocket* /*connection*/) {
        }

        virtual void onData(WebSocket* connection, const uint8_t* data, size_t length) {
        connection->send(data, length); // binary
        }

        virtual void onData(WebSocket* connection, const char* data) {
        connection->send(data); // text
        }

        virtual void onDisconnect(WebSocket* /*connection*/) {
        }
    };

    int main(int /*argc*/, const char* /*argv*/[]) {
        std::shared_ptr<Logger> logger(new PrintfLogger(Logger::Level::DEBUG));

        Server server(logger);
        std::shared_ptr<EchoHandler> handler(new EchoHandler());
        server.addWebSocketHandler("/", handler);
        server.serve("/dev/null", 8000);
        return 0;
    }

这些是我的构建错误:

    04:40:40 **** Build of configuration Debug for project HSServer ****
    make all 
    Building file: ../src/HSServer.cpp
    Invoking: GCC C++ Compiler
    g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/HSServer.d" -MT"src/HSServer.o" -o "src/HSServer.o" "../src/HSServer.cpp"
    Finished building: ../src/HSServer.cpp

    Building target: HSServer
    Invoking: GCC C++ Linker
    g++  -o "HSServer"  ./src/HSServer.o   
    ./src/HSServer.o: In function `main':
    /home/xnite/workspace/HSServer/Debug/../src/HSServer.cpp:37: undefined reference to `seasocks::Server::Server(std::shared_ptr<seasocks::Logger>)'
    /home/xnite/workspace/HSServer/Debug/../src/HSServer.cpp:39: undefined reference to `seasocks::Server::addWebSocketHandler(char const*, std::shared_ptr<seasocks::WebSocket::Handler>, bool)'
    /home/xnite/workspace/HSServer/Debug/../src/HSServer.cpp:40: undefined reference to `seasocks::Server::serve(char const*, int)'
    /home/xnite/workspace/HSServer/Debug/../src/HSServer.cpp:37: undefined reference to `seasocks::Server::~Server()'
    /home/xnite/workspace/HSServer/Debug/../src/HSServer.cpp:37: undefined reference to `seasocks::Server::~Server()'
    collect2: error: ld returned 1 exit status
    make: *** [makefile:47: HSServer] Error 1

    04:40:45 Build Finished (took 5s.239ms)

Answer 1

您必须链接库。例如 -

g++ -o myfile objfileA.o objfileB.o -lLibName

这里的 libName 是库的名称。对于 Linux 中的 ex - 对于库 libfoo.so，您只需编写 -lfoo。但在 Windows 中它将是 foo.lib。您可能必须使用 -L‹path_to_dir› 添加目录，并且在 -l 或 -L 之后没有任何空格来定位文件。

如果使用 IDE，请根据 IDE 在其他库目录下指定它。