小编Dek*_*ruk的帖子

我试图通过linux socket发送一些文件描述符,但它不起作用.我究竟做错了什么？一个人应该如何调试这样的东西？我尝试在可能的地方放置perror(),但他们声称一切正常.这是我写的:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <fcntl.h>

void wyslij(int socket, int fd)  // send fd by socket
{
    struct msghdr msg = {0};

    char buf[CMSG_SPACE(sizeof fd)];

    msg.msg_control = buf;
    msg.msg_controllen = sizeof buf;

    struct cmsghdr * cmsg = CMSG_FIRSTHDR(&msg);
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type = SCM_RIGHTS;
    cmsg->cmsg_len = CMSG_LEN(sizeof fd);

    *((int *) CMSG_DATA(cmsg)) = fd;

    msg.msg_controllen = cmsg->cmsg_len;  // why does example from man need it? isn't it redundant?

    sendmsg(socket, …

我的问题通过以下示例说明:

#include <set>

class A {};

int main()
{
    A a;
    A * p = &a;
    const A * cp = &a;

    std::set<A*> s;
    s.insert(p);
    s.find(cp);
}

编译以:

a.cpp: In function ‘int main()’:
a.cpp:13:18: error: invalid conversion from ‘const A*’ to ‘std::set<A*>::key_type {aka A*}’ [-fpermissive]
         s.find(cp);
                  ^
In file included from /usr/include/c++/4.9.1/set:61:0,
                 from a.cpp:1:
/usr/include/c++/4.9.1/bits/stl_set.h:701:7: note: initializing argument 1 of ‘std::set<_Key, _Compare, _Alloc>::iterator std::set<_Key, _Compare, _Alloc>::find(const key_type&) [with _Key = A*; _Compare = std::less<A*>; _Alloc = std::allocator<A*>; std::set<_Key, _Compare, _Alloc>::iterator …

我正在尝试构建我的kivy应用程序,但运行buildozer android debug --verbose我唯一得到的是:

[...]

Run prebuild
Call prebuild_hostpython
Call prebuild_python
Call prebuild_sdl
Call prebuild_pygame
Call prebuild_pyjnius
Call prebuild_android
Call prebuild_kivy
Run build
Skipped build_hostpython
Skipped build_python
Skipped build_sdl
Skipped build_pygame
Call build_pyjnius
Entering in ARM environment
Compiler found at /home/michal/.buildozer/android/platform/android-ndk-r9c/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc
/home/michal/Dokumenty/Projekty/Labirynt/.buildozer/android/platform/python-for-android/build/python-install/lib/python2.7/distutils/dist.py:267: UserWarning: Unknown distribution option: 'install_requires'
  warnings.warn(msg)
running build_ext
building 'jnius' extension
arm-linux-androideabi-gcc -DANDROID -mandroid -fomit-frame-pointer --sysroot /home/michal/.buildozer/android/platform/android-ndk-r9c/platforms/android-14/arch-arm -DNDEBUG -DANDROID -mandroid -fomit-frame-pointer --sysroot /home/michal/.buildozer/android/platform/android-ndk-r9c/platforms/android-14/arch-arm -fPIC -I/home/michal/Dokumenty/Projekty/Labirynt/.buildozer/android/platform/python-for-android/build/python-install/include/python2.7 -c jnius/jnius.c -o build/temp.linux-x86_64-2.7/jnius/jnius.o
jnius/jnius.c:1:2: error: #error Do not use this …