/*
 * This file is part of the KDE libraries
 * Copyright (c) 1999-2000 Waldo Bastian <bastian@kde.org>
 *           (c) 1999 Mario Weilguni <mweilguni@sime.com>
 *           (c) 2001 Lubos Lunak <l.lunak@kde.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include <config-kdeinit.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#if HAVE_SYS_SELECT_H
#include <sys/select.h>     // Needed on some systems.
#endif

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include "proctitle.h"
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>

#include <QtCore/QLibrary>
#include <QtCore/QString>
#include <QtCore/QFile>
#include <QtCore/QDate>
#include <QtCore/QDir>
#include <QtCore/QFileInfo>
#include <QtCore/QRegExp>
#include <QFont>
#include <kcrash.h>
#include <klibrary.h>
#include <kconfig.h>
#include <klocalizedstring.h>
#include <QDebug>
#include <qsavefile.h>

#ifdef Q_OS_LINUX
#include <sys/prctl.h>
#ifndef PR_SET_NAME
#define PR_SET_NAME 15
#endif
#endif

#ifdef Q_OS_MAC
#include <CoreFoundation/CFBundle.h>
#include <CoreFoundation/CFString.h>
#include <CoreFoundation/CFURL.h>
#endif

#include <kinit_version.h>

#include "klauncher_cmds.h"

#if HAVE_X11
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <fixx11h.h>
#include <kstartupinfo.h>
#endif
#include <qstandardpaths.h>

#ifdef Q_OS_UNIX
//TODO: make sure what libraries we want here...
static const char *extra_libs[] = {
    "libKIOCore.so.5",
    "libKParts.so.5",
//#ifdef __KDE_HAVE_GCC_VISIBILITY // Removed for KF5, we'll see.
    "libPlasma.so.5"
//#endif
};
#endif

// #define SKIP_PROCTITLE 1

namespace KCrash
{
extern KCRASH_EXPORT bool loadedByKdeinit;
}

extern char **environ;

#if HAVE_X11
static int X11fd = -1;
static Display *X11display = 0;
static int X11_startup_notify_fd = -1;
static Display *X11_startup_notify_display = 0;
#endif
#define MAX_SOCK_FILE 255
static char sock_file[MAX_SOCK_FILE];

static QByteArray displayEnvVarName()
{
    // Can't use QGuiApplication::platformName() here, there is no app instance.
#if HAVE_X11
    return "DISPLAY";
#elif defined(Q_OS_MACX)
    return "MAC_DISPLAY";
#elif defined(Q_OS_WIN)
    return "WIN_DISPLAY";
#endif
}

/* Group data */
static struct {
    int maxname;
    int fd[2];
    int launcher[2]; /* socket pair for launcher communication */
    int deadpipe[2]; /* pipe used to detect dead children */
    int initpipe[2];
    int wrapper; /* socket for wrapper communication */
    int accepted_fd; /* socket accepted and that must be closed in the child process */
    char result;
    int exit_status;
    pid_t fork;
    pid_t launcher_pid;
    pid_t kded_pid;
    int n;
    char **argv;
    int (*func)(int, char *[]);
    int (*launcher_func)(int);
    bool debug_wait;
    QByteArray errorMsg;
    bool launcher_ok;
    bool suicide;
} d;

struct child {
    pid_t pid;
    int sock; /* fd to write message when child is dead*/
    struct child *next;
};

static struct child *children;

#if HAVE_X11
extern "C" {
    int kdeinit_xio_errhandler(Display *);
    int kdeinit_x_errhandler(Display *, XErrorEvent *err);
}
#endif

#if KDEINIT_OOM_PROTECT
static int oom_pipe = -1;
#endif

/*
 * Clean up the file descriptor table by closing all file descriptors
 * that are still open.
 *
 * This function is called very early in the main() function, so that
 * we don't leak anything that was leaked to us.
 */
static void cleanup_fds()
{
    int maxfd = FD_SETSIZE;
    struct rlimit rl;
    if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
        maxfd = rl.rlim_max;
    }
    for (int fd = 3; fd < maxfd; ++fd) {
#if KDEINIT_OOM_PROTECT
        if (fd != oom_pipe)
#endif
            close(fd);
    }
}

/*
 * Close fd's which are only useful for the parent process.
 * Restore default signal handlers.
 */
static void close_fds()
{
    while (struct child *child = children) {
        close(child->sock);
        children = child->next;
        free(child);
    }

    if (d.deadpipe[0] != -1) {
        close(d.deadpipe[0]);
        d.deadpipe[0] = -1;
    }

    if (d.deadpipe[1] != -1) {
        close(d.deadpipe[1]);
        d.deadpipe[1] = -1;
    }

    if (d.initpipe[0] != -1) {
        close(d.initpipe[0]);
        d.initpipe[0] = -1;
    }

    if (d.initpipe[1] != -1) {
        close(d.initpipe[1]);
        d.initpipe[1] = -1;
    }

    if (d.launcher[0] != -1) {
        close(d.launcher[0]);
        d.launcher[0] = -1;
    }
    if (d.wrapper != -1) {
        close(d.wrapper);
        d.wrapper = -1;
    }
    if (d.accepted_fd != -1) {
        close(d.accepted_fd);
        d.accepted_fd = -1;
    }
#if HAVE_X11
    if (X11fd >= 0) {
        close(X11fd);
        X11fd = -1;
    }
    if (X11_startup_notify_fd >= 0 && X11_startup_notify_fd != X11fd) {
        close(X11_startup_notify_fd);
        X11_startup_notify_fd = -1;
    }
#endif

    signal(SIGCHLD, SIG_DFL);
    signal(SIGPIPE, SIG_DFL);
}

/* Notify wrapper program that the child it started has finished. */
static void child_died(pid_t exit_pid, int exit_status)
{
    struct child *child, **childptr = &children;

    while ((child = *childptr)) {
        if (child->pid == exit_pid) {
            /* Send a message with the return value of the child on the control socket */
            klauncher_header request_header;
            long request_data[2];
            request_header.cmd = LAUNCHER_CHILD_DIED;
            request_header.arg_length = sizeof(long) * 2;
            request_data[0] = exit_pid;
            request_data[1] = exit_status;
            write(child->sock, &request_header, sizeof(request_header));
            write(child->sock, request_data, request_header.arg_length);
            close(child->sock);

            *childptr = child->next;
            free(child);
            return;
        }

        childptr = &child->next;
    }
}

static void exitWithErrorMsg(const QString &errorMsg)
{
    fprintf(stderr, "%s\n", errorMsg.toLocal8Bit().data());
    QByteArray utf8ErrorMsg = errorMsg.toUtf8();
    d.result = 3; // Error with msg
    write(d.fd[1], &d.result, 1);
    int l = utf8ErrorMsg.length();
    write(d.fd[1], &l, sizeof(int));
    write(d.fd[1], utf8ErrorMsg.data(), l);
    close(d.fd[1]);
    exit(255);
}

static void setup_tty(const char *tty)
{
    if (tty == NULL || *tty == '\0') {
        return;
    }
    QFile f(QFile::decodeName(tty));
    f.open(QFileDevice::WriteOnly);
    int fd = f.handle();

    if (fd < 0) {
        perror("kdeinit5: could not open() tty");
        return;
    }
    if (dup2(fd, STDOUT_FILENO) < 0) {
        perror("kdeinit5: could not dup2() stdout tty");
    }
    if (dup2(fd, STDERR_FILENO) < 0) {
        perror("kdeinit5: could not dup2() stderr tty");
    }
    close(fd);
}

#if HAVE_X11 // Only X11 supports multiple desktops
// from kdecore/netwm.cpp
static int get_current_desktop(Display *disp)
{
    int desktop = 0; // no desktop by default
    Atom net_current_desktop = XInternAtom(disp, "_NET_CURRENT_DESKTOP", False);
    Atom type_ret;
    int format_ret;
    unsigned char *data_ret;
    unsigned long nitems_ret, unused;
    if (XGetWindowProperty(disp, DefaultRootWindow(disp), net_current_desktop,
                           0l, 1l, False, XA_CARDINAL, &type_ret, &format_ret, &nitems_ret, &unused, &data_ret)
            == Success) {
        if (type_ret == XA_CARDINAL && format_ret == 32 && nitems_ret == 1) {
            desktop = *((long *) data_ret) + 1;
        }
        if (data_ret) {
            XFree((char *) data_ret);
        }
    }
    return desktop;
}
#endif

// var has to be e.g. "DISPLAY=", i.e. with =
const char *get_env_var(const char *var, int envc, const char *envs)
{
    if (envc > 0) {
        // get the var from envs
        const char *env_l = envs;
        int ln = strlen(var);
        for (int i = 0;  i < envc; i++) {
            if (strncmp(env_l, var, ln) == 0) {
                return env_l + ln;
            }
            while (*env_l != 0) {
                env_l++;
            }
            env_l++;
        }
    }
    return NULL;
}

#if HAVE_X11
static void init_startup_info(KStartupInfoId &id, const QByteArray &bin,
                              int envc, const char *envs)
{
    QByteArray envname = displayEnvVarName() + "=";
    const char *dpy = get_env_var(envname.constData(), envc, envs);
    // this may be called in a child, so it can't use display open using X11display
    // also needed for multihead
    X11_startup_notify_display = XOpenDisplay(dpy);
    if (X11_startup_notify_display == NULL) {
        return;
    }
    X11_startup_notify_fd = XConnectionNumber(X11_startup_notify_display);
    KStartupInfoData data;
    int desktop = get_current_desktop(X11_startup_notify_display);
    data.setDesktop(desktop);
    data.setBin(QFile::decodeName(bin));
    KStartupInfo::sendChangeX(X11_startup_notify_display, id, data);
    XFlush(X11_startup_notify_display);
}

static void complete_startup_info(KStartupInfoId &id, pid_t pid)
{
    if (X11_startup_notify_display == NULL) {
        return;
    }
    if (pid == 0) { // failure
        KStartupInfo::sendFinishX(X11_startup_notify_display, id);
    } else {
        KStartupInfoData data;
        data.addPid(pid);
        data.setHostname();
        KStartupInfo::sendChangeX(X11_startup_notify_display, id, data);
    }
    XCloseDisplay(X11_startup_notify_display);
    X11_startup_notify_display = NULL;
    X11_startup_notify_fd = -1;
}
#endif

QByteArray execpath_avoid_loops(const QByteArray &exec, int envc, const char *envs, bool avoid_loops)
{
    QStringList paths;
    const QRegExp pathSepRegExp(QString::fromLatin1("[:\b]"));
    if (envc > 0) { /* use the passed environment */
        const char *path = get_env_var("PATH=", envc, envs);
        if (path != NULL) {
            paths = QFile::decodeName(path).split(pathSepRegExp);
        }
    } else {
        paths = QString::fromLocal8Bit(qgetenv("PATH")).split(pathSepRegExp, QString::KeepEmptyParts);
        paths.prepend(QFile::decodeName(CMAKE_INSTALL_PREFIX "/" LIBEXEC_INSTALL_DIR));
    }
    QString execpath = QStandardPaths::findExecutable(QFile::decodeName(exec), paths);
    if (avoid_loops && !execpath.isEmpty()) {
        const int pos = execpath.lastIndexOf(QLatin1Char('/'));
        const QString bin_path = execpath.left(pos);
        for (QStringList::Iterator it = paths.begin();
                it != paths.end();
                ++it) {
            if (*it == bin_path || *it == bin_path + QLatin1Char('/')) {
                paths.erase(it);
                break; // -->
            }
        }
        execpath = QStandardPaths::findExecutable(QFile::decodeName(exec), paths);
    }
    return QFile::encodeName(execpath);
}

#if KDEINIT_OOM_PROTECT
static void oom_protect_sighandler(int)
{
}

static void reset_oom_protect()
{
    if (oom_pipe <= 0) {
        return;
    }
    struct sigaction act, oldact;
    act.sa_handler = oom_protect_sighandler;
    act.sa_flags = 0;
    sigemptyset(&act.sa_mask);
    sigaction(SIGUSR1, &act, &oldact);
    sigset_t sigs, oldsigs;
    sigemptyset(&sigs);
    sigaddset(&sigs, SIGUSR1);
    sigprocmask(SIG_BLOCK, &sigs, &oldsigs);
    pid_t pid = getpid();
    if (write(oom_pipe, &pid, sizeof(pid_t)) > 0) {
        sigsuspend(&oldsigs);   // wait for the signal to come
    } else {
#ifndef NDEBUG
        fprintf(stderr, "Failed to reset OOM protection: %d\n", pid);
#endif
    }
    sigprocmask(SIG_SETMASK, &oldsigs, NULL);
    sigaction(SIGUSR1, &oldact, NULL);
    close(oom_pipe);
    oom_pipe = -1;
}
#else
static void reset_oom_protect()
{
}
#endif

static pid_t launch(int argc, const char *_name, const char *args,
                    const char *cwd = 0, int envc = 0, const char *envs = 0,
                    bool reset_env = false,
                    const char *tty = 0, bool avoid_loops = false,
                    const char *startup_id_str = "0")  // krazy:exclude=doublequote_chars
{
    QString lib;
    QByteArray name;
    QByteArray exec;
    QString libpath;
    QByteArray execpath;

    if (_name[0] != '/') {
        name = _name;
        lib = QFile::decodeName(name);
        exec = name;
        KLibrary klib(QLatin1String("libkdeinit5_") + lib);
        libpath = klib.fileName();
        if (libpath.isEmpty()) {
            KLibrary klib(lib);
            libpath = klib.fileName(); // this is really just a way to call findLibraryInternal
        }
        execpath = execpath_avoid_loops(exec, envc, envs, avoid_loops);
        if (libpath.isEmpty() && execpath.isEmpty()) {
            fprintf(stderr, "Didn't find \"%s\", neither as an executable nor as a plugin. Please check $PATH and $QT_PLUGIN_PATH.\n", name.constData());
        }
    } else {
        name = _name;
        lib = QFile::decodeName(name);
        name = name.mid(name.lastIndexOf('/') + 1);
        exec = _name;
        if (lib.endsWith(QLatin1String(".so"))) {
            libpath = lib;
        } else {
            // try to match an absolute path to an executable binary (either in bin/ or in libexec/)
            // to a kdeinit module in the same prefix
            if (lib.contains(QLatin1String(LIBEXEC_INSTALL_DIR))) {
                libpath = QString(lib).replace(QLatin1String(LIBEXEC_INSTALL_DIR),
                                               QLatin1String(LIB_INSTALL_DIR "/libkdeinit5_")) + QLatin1String(".so");
            } else if (lib.contains(QLatin1String("/bin/"))) {
                libpath = QString(lib).replace(QLatin1String("/bin/"),
                                               QLatin1String(LIB_INSTALL_DIR "/libkdeinit5_")) + QLatin1String(".so");
            }
            // Don't confuse the user with "Could not load libkdeinit5_foo.so" if it doesn't exist
            if (!QFile::exists(libpath)) {
                libpath.clear();
            }
            execpath = exec;
        }
    }
#ifndef NDEBUG
    fprintf(stderr, "kdeinit5: preparing to launch '%s'\n", libpath.isEmpty()
            ? execpath.constData() : libpath.toUtf8().constData());
#endif
    if (!args) {
        argc = 1;
    }

    if (0 > pipe(d.fd)) {
        perror("kdeinit5: pipe() failed");
        d.result = 3;
        d.errorMsg = i18n("Unable to start new process.\n"
                          "The system may have reached the maximum number of open files possible or the maximum number of open files that you are allowed to use has been reached.").toUtf8();
        d.fork = 0;
        return d.fork;
    }

#if HAVE_X11
    KStartupInfoId startup_id;
    startup_id.initId(startup_id_str);
    if (!startup_id.none()) {
        init_startup_info(startup_id, name, envc, envs);
    }
#endif
    // find out this path before forking, doing it afterwards
    // crashes on some platforms, notably OSX
#ifdef Q_OS_MAC
    const QString bundlepath = QStandardPaths::findExecutable(QFile::decodeName(execpath));
#endif

    d.errorMsg = 0;
    d.fork = fork();
    switch (d.fork) {
    case -1:
        perror("kdeinit5: fork() failed");
        d.result = 3;
        d.errorMsg = i18n("Unable to create new process.\n"
                          "The system may have reached the maximum number of processes possible or the maximum number of processes that you are allowed to use has been reached.").toUtf8();
        close(d.fd[0]);
        close(d.fd[1]);
        d.fork = 0;
        break;
    case 0: {
        /** Child **/
        close(d.fd[0]);
        close_fds();
        reset_oom_protect();

        // Try to chdir, either to the requested directory or to the user's document path by default.
        // We ignore errors - if you write a desktop file with Exec=foo and Path=/doesnotexist,
        // we still want to execute `foo` even if the chdir() failed.
        if (cwd && *cwd) {
            (void)chdir(cwd);
        }

        if (reset_env) { // KWRAPPER/SHELL

            QList<QByteArray> unset_envs;
            for (int tmp_env_count = 0;
                    environ[tmp_env_count];
                    tmp_env_count++) {
                unset_envs.append(environ[ tmp_env_count ]);
            }
            foreach (const QByteArray &tmp, unset_envs) {
                int pos = tmp.indexOf('=');
                if (pos >= 0) {
                    unsetenv(tmp.left(pos).constData());
                }
            }
        }

        for (int i = 0;  i < envc; i++) {
            putenv((char *)envs);
            while (*envs != 0) {
                envs++;
            }
            envs++;
        }

#if HAVE_X11
        if (startup_id.none()) {
            KStartupInfo::resetStartupEnv();
        } else {
            startup_id.setupStartupEnv();
        }
#endif
        {
            int r;
            QByteArray procTitle;
            d.argv = (char **) malloc(sizeof(char *) * (argc + 1));
            d.argv[0] = (char *) _name;
#ifdef Q_OS_MAC
            QString argvexe = QStandardPaths::findExecutable(QString::fromLatin1(d.argv[0]));
            if (!argvexe.isEmpty()) {
                QByteArray cstr = argvexe.toLocal8Bit();
                // qDebug() << "kdeinit5: launch() setting argv: " << cstr.data();
                d.argv[0] = strdup(cstr.data());
            }
#endif
            for (int i = 1;  i < argc; i++) {
                d.argv[i] = (char *) args;
                procTitle += ' ';
                procTitle += (char *) args;
                while (*args != 0) {
                    args++;
                }
                args++;
            }
            d.argv[argc] = 0;

#ifndef SKIP_PROCTITLE
            /** Give the process a new name **/
#ifdef Q_OS_LINUX
            /* set the process name, so that killall works like intended */
            r = prctl(PR_SET_NAME, (unsigned long) name.data(), 0, 0, 0);
            if (r == 0) {
                proctitle_set("%s [kdeinit]%s", name.data(), procTitle.data() ? procTitle.data() : "");
            } else {
                proctitle_set("kdeinit5: %s%s", name.data(), procTitle.data() ? procTitle.data() : "");
            }
#else
            proctitle_set("kdeinit5: %s%s", name.data(), procTitle.data() ? procTitle.data() : "");
#endif
#endif
        }

        if (libpath.isEmpty() && execpath.isEmpty()) {
            QString errorMsg = i18n("Could not find '%1' executable.", QFile::decodeName(_name));
            exitWithErrorMsg(errorMsg);
        }

        if (!qgetenv("KDE_IS_PRELINKED").isEmpty() && !execpath.isEmpty()) {
            libpath.truncate(0);
        }

        QLibrary l(libpath);

        if (!libpath.isEmpty()) {
            if (!l.load() || !l.isLoaded()) {
                QString ltdlError(l.errorString());
                if (execpath.isEmpty()) {
                    // Error
                    QString errorMsg = i18n("Could not open library '%1'.\n%2", libpath, ltdlError);
                    exitWithErrorMsg(errorMsg);
                } else {
                    // Print warning
                    fprintf(stderr, "Could not open library %s: %s\n", qPrintable(lib),
                            qPrintable(ltdlError));
                }
            }
        }
        if (!l.isLoaded()) {
            d.result = 2; // Try execing
            write(d.fd[1], &d.result, 1);

            // We set the close on exec flag.
            // Closing of d.fd[1] indicates that the execvp succeeded!
            fcntl(d.fd[1], F_SETFD, FD_CLOEXEC);

            setup_tty(tty);

            QByteArray executable = execpath;
#ifdef Q_OS_MAC
            if (!bundlepath.isEmpty()) {
                executable = QFile::encodeName(bundlepath);
            }
#endif

            if (!executable.isEmpty()) {
                execvp(executable.constData(), d.argv);
            }

            d.result = 1; // Error
            write(d.fd[1], &d.result, 1);
            close(d.fd[1]);
            exit(255);
        }

        QFunctionPointer sym = l.resolve("kdeinitmain");
        if (!sym) {
            sym = l.resolve("kdemain");
            if (!sym) {
                QString ltdlError = l.errorString();
                fprintf(stderr, "Could not find kdemain: %s\n", qPrintable(ltdlError));
                QString errorMsg = i18n("Could not find 'kdemain' in '%1'.\n%2",
                                        libpath, ltdlError);
                exitWithErrorMsg(errorMsg);
            }
        }

        d.result = 0; // Success
        write(d.fd[1], &d.result, 1);
        close(d.fd[1]);

        d.func = (int (*)(int, char *[])) sym;
        if (d.debug_wait) {
            fprintf(stderr, "kdeinit5: Suspending process\n"
                    "kdeinit5: 'gdb kdeinit5 %d' to debug\n"
                    "kdeinit5: 'kill -SIGCONT %d' to continue\n",
                    getpid(), getpid());
            kill(getpid(), SIGSTOP);
        } else {
            setup_tty(tty);
        }

        exit(d.func(argc, d.argv));  /* Launch! */

        break;
    }
    default:
        /** Parent **/
        close(d.fd[1]);
        bool exec = false;
        for (;;) {
            d.n = read(d.fd[0], &d.result, 1);
            if (d.n == 1) {
                if (d.result == 2) {
#ifndef NDEBUG
                    //fprintf(stderr, "kdeinit5: no kdeinit module, trying exec....\n");
#endif
                    exec = true;
                    continue;
                }
                if (d.result == 3) {
                    int l = 0;
                    d.n = read(d.fd[0], &l, sizeof(int));
                    if (d.n == sizeof(int)) {
                        QByteArray tmp;
                        tmp.resize(l + 1);
                        d.n = read(d.fd[0], tmp.data(), l);
                        tmp[l] = 0;
                        if (d.n == l) {
                            d.errorMsg = tmp;
                        }
                    }
                }
                // Finished
                break;
            }
            if (d.n == -1) {
                if (errno == ECHILD) {  // a child died.
                    continue;
                }
                if (errno == EINTR || errno == EAGAIN) { // interrupted or more to read
                    continue;
                }
            }
            if (d.n == 0) {
                if (exec) {
                    d.result = 0;
                } else {
                    fprintf(stderr, "kdeinit5: (%s %s) Pipe closed unexpectedly", name.constData(), execpath.constData());
                    perror("kdeinit5: Pipe closed unexpectedly");
                    d.result = 1; // Error
                }
                break;
            }
            perror("kdeinit5: Error reading from pipe");
            d.result = 1; // Error
            break;
        }
        close(d.fd[0]);
    }
#if HAVE_X11
    if (!startup_id.none()) {
        if (d.fork && d.result == 0) { // launched successfully
            complete_startup_info(startup_id, d.fork);
        } else { // failure, cancel ASN
            complete_startup_info(startup_id, 0);
        }
    }
#endif
    return d.fork;
}

extern "C" {

    static void sig_child_handler(int)
    {
        /*
         * Write into the pipe of death.
         * This way we are sure that we return from the select()
         *
         * A signal itself causes select to return as well, but
         * this creates a race-condition in case the signal arrives
         * just before we enter the select.
         */
        char c = 0;
        write(d.deadpipe[1], &c, 1);
    }

}

static void init_signals()
{
    struct sigaction act;
    long options;

    if (pipe(d.deadpipe) != 0) {
        perror("kdeinit5: Aborting. Can not create pipe");
        exit(255);
    }

    options = fcntl(d.deadpipe[0], F_GETFL);
    if (options == -1) {
        perror("kdeinit5: Aborting. Can not make pipe non-blocking");
        exit(255);
    }

    if (fcntl(d.deadpipe[0], F_SETFL, options | O_NONBLOCK) == -1) {
        perror("kdeinit5: Aborting. Can not make pipe non-blocking");
        exit(255);
    }

    /*
     * A SIGCHLD handler is installed which sends a byte into the
     * pipe of death. This is to ensure that a dying child causes
     * an exit from select().
     */
    act.sa_handler = sig_child_handler;
    sigemptyset(&(act.sa_mask));
    sigaddset(&(act.sa_mask), SIGCHLD);
    sigprocmask(SIG_UNBLOCK, &(act.sa_mask), 0L);
    act.sa_flags = SA_NOCLDSTOP;

    // CC: take care of SunOS which automatically restarts interrupted system
    // calls (and thus does not have SA_RESTART)

#ifdef SA_RESTART
    act.sa_flags |= SA_RESTART;
#endif
    sigaction(SIGCHLD, &act, 0L);

    act.sa_handler = SIG_IGN;
    sigemptyset(&(act.sa_mask));
    sigaddset(&(act.sa_mask), SIGPIPE);
    sigprocmask(SIG_UNBLOCK, &(act.sa_mask), 0L);
    act.sa_flags = 0;
    sigaction(SIGPIPE, &act, 0L);
}

static void init_kdeinit_socket()
{
    struct sockaddr_un sa;
    kde_socklen_t socklen;
    long options;
    const QByteArray home_dir = qgetenv("HOME");
    int max_tries = 10;
    if (home_dir.isEmpty()) {
        fprintf(stderr, "kdeinit5: Aborting. $HOME not set!");
        exit(255);
    }
    if (chdir(home_dir.constData()) != 0) {
        fprintf(stderr, "kdeinit5: Aborting. Couldn't enter '%s'!", home_dir.constData());
        exit(255);
    }

    {
        QByteArray path = home_dir;
        QByteArray readOnly = qgetenv("KDE_HOME_READONLY");
        if (access(path.data(), R_OK | W_OK)) {
            if (errno == ENOENT) {
                fprintf(stderr, "kdeinit5: Aborting. $HOME directory (%s) does not exist.\n", path.data());
                exit(255);
            } else if (readOnly.isEmpty()) {
                fprintf(stderr, "kdeinit5: Aborting. No write access to $HOME directory (%s).\n", path.data());
                exit(255);
            }
        }
#if 0 // obsolete in kde4. Should we check writing to another file instead?
        path = qgetenv("ICEAUTHORITY");
        if (path.isEmpty()) {
            path = home_dir;
            path += "/.ICEauthority";
        }
        if (access(path.data(), R_OK | W_OK) && (errno != ENOENT)) {
            fprintf(stderr, "kdeinit5: Aborting. No write access to '%s'.\n", path.data());
            exit(255);
        }
#endif
    }

    /** Test if socket file is already present
     *  note that access() resolves symlinks, and so we check the actual
     *  socket file if it exists
     */
    if (access(sock_file, W_OK) == 0) {
        int s;
        struct sockaddr_un server;

//     fprintf(stderr, "kdeinit5: Warning, socket_file already exists!\n");
        /*
         * create the socket stream
         */
        s = socket(PF_UNIX, SOCK_STREAM, 0);
        if (s < 0) {
            perror("socket() failed");
            exit(255);
        }
        server.sun_family = AF_UNIX;
        strcpy(server.sun_path, sock_file);
        socklen = sizeof(server);

        if (connect(s, (struct sockaddr *)&server, socklen) == 0) {
            fprintf(stderr, "kdeinit5: Shutting down running client.\n");
            klauncher_header request_header;
            request_header.cmd = LAUNCHER_TERMINATE_KDEINIT;
            request_header.arg_length = 0;
            write(s, &request_header, sizeof(request_header));
            sleep(1); // Give it some time
        }
        close(s);
    }

    /** Delete any stale socket file (and symlink) **/
    unlink(sock_file);

    /** create socket **/
    d.wrapper = socket(PF_UNIX, SOCK_STREAM, 0);
    if (d.wrapper < 0) {
        perror("kdeinit5: Aborting. socket() failed");
        exit(255);
    }

    options = fcntl(d.wrapper, F_GETFL);
    if (options == -1) {
        perror("kdeinit5: Aborting. Can not make socket non-blocking");
        close(d.wrapper);
        exit(255);
    }

    if (fcntl(d.wrapper, F_SETFL, options | O_NONBLOCK) == -1) {
        perror("kdeinit5: Aborting. Can not make socket non-blocking");
        close(d.wrapper);
        exit(255);
    }

    while (1) {
        /** bind it **/
        socklen = sizeof(sa);
        memset(&sa, 0, socklen);
        sa.sun_family = AF_UNIX;
        strcpy(sa.sun_path, sock_file);
        if (bind(d.wrapper, (struct sockaddr *)&sa, socklen) != 0) {
            if (max_tries == 0) {
                perror("kdeinit5: Aborting. bind() failed");
                fprintf(stderr, "Could not bind to socket '%s'\n", sock_file);
                close(d.wrapper);
                exit(255);
            }
            max_tries--;
        } else {
            break;
        }
    }

    /** set permissions **/
    if (chmod(sock_file, 0600) != 0) {
        perror("kdeinit5: Aborting. Can not set permissions on socket");
        fprintf(stderr, "Wrong permissions of socket '%s'\n", sock_file);
        unlink(sock_file);
        close(d.wrapper);
        exit(255);
    }

    if (listen(d.wrapper, SOMAXCONN) < 0) {
        perror("kdeinit5: Aborting. listen() failed");
        unlink(sock_file);
        close(d.wrapper);
        exit(255);
    }
}

/*
 * Read 'len' bytes from 'sock' into buffer.
 * returns 0 on success, -1 on failure.
 */
static int read_socket(int sock, char *buffer, int len)
{
    ssize_t result;
    int bytes_left = len;
    while (bytes_left > 0) {
        result = read(sock, buffer, bytes_left);
        if (result > 0) {
            buffer += result;
            bytes_left -= result;
        } else if (result == 0) {
            return -1;
        } else if ((result == -1) && (errno != EINTR) && (errno != EAGAIN)) {
            return -1;
        }
    }
    return 0;
}

static void start_klauncher()
{
    if (socketpair(AF_UNIX, SOCK_STREAM, 0, d.launcher) < 0) {
        perror("kdeinit5: socketpair() failed");
        exit(255);
    }
    char args[32];
    strcpy(args, "--fd=");
    sprintf(args + 5, "%d", d.launcher[1]);
    d.launcher_pid = launch(2, "klauncher", args);
    close(d.launcher[1]);
#ifndef NDEBUG
    fprintf(stderr, "kdeinit5: Launched KLauncher, pid = %ld, result = %d\n",
            (long) d.launcher_pid, d.result);
#endif
}

static void launcher_died()
{
    if (!d.launcher_ok) {
        /* This is bad. */
        fprintf(stderr, "kdeinit5: Communication error with launcher. Exiting!\n");
        ::exit(255);
        return;
    }

    // KLauncher died... restart
#ifndef NDEBUG
    fprintf(stderr, "kdeinit5: KLauncher died unexpectedly.\n");
#endif
    // Make sure it's really dead.
    if (d.launcher_pid) {
        kill(d.launcher_pid, SIGKILL);
        sleep(1); // Give it some time
    }

    d.launcher_ok = false;
    d.launcher_pid = 0;
    close(d.launcher[0]);
    d.launcher[0] = -1;

    start_klauncher();
}

static bool handle_launcher_request(int sock, const char *who)
{
    (void)who; // for NDEBUG

    klauncher_header request_header;
    char *request_data = 0L;
    int result = read_socket(sock, (char *) &request_header, sizeof(request_header));
    if (result != 0) {
        return false;
    }

    if (request_header.arg_length != 0) {
        request_data = (char *) malloc(request_header.arg_length);

        result = read_socket(sock, request_data, request_header.arg_length);
        if (result != 0) {
            free(request_data);
            return false;
        }
    }

    //qDebug() << "Got cmd" << request_header.cmd << commandToString(request_header.cmd);
    if (request_header.cmd == LAUNCHER_OK) {
        d.launcher_ok = true;
    } else if (request_header.arg_length &&
               ((request_header.cmd == LAUNCHER_EXEC) ||
                (request_header.cmd == LAUNCHER_EXT_EXEC) ||
                (request_header.cmd == LAUNCHER_SHELL) ||
                (request_header.cmd == LAUNCHER_KWRAPPER) ||
                (request_header.cmd == LAUNCHER_EXEC_NEW))) {
        pid_t pid;
        klauncher_header response_header;
        long response_data;
        long l;
        memcpy(&l, request_data, sizeof(long));
        int argc = l;
        const char *name = request_data + sizeof(long);
        const char *args = name + strlen(name) + 1;
        const char *cwd = 0;
        int envc = 0;
        const char *envs = 0;
        const char *tty = 0;
        int avoid_loops = 0;
        const char *startup_id_str = "0"; // krazy:exclude=doublequote_chars

#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: Got %s '%s' from %s.\n",
                commandToString(request_header.cmd),
                name, who);
#endif

        const char *arg_n = args;
        for (int i = 1; i < argc; i++) {
            arg_n = arg_n + strlen(arg_n) + 1;
        }

        if (request_header.cmd == LAUNCHER_SHELL || request_header.cmd == LAUNCHER_KWRAPPER) {
            // Shell or kwrapper
            cwd = arg_n; arg_n += strlen(cwd) + 1;
        }
        if (request_header.cmd == LAUNCHER_SHELL || request_header.cmd == LAUNCHER_KWRAPPER
                || request_header.cmd == LAUNCHER_EXT_EXEC || request_header.cmd == LAUNCHER_EXEC_NEW) {
            memcpy(&l, arg_n, sizeof(long));
            envc = l;
            arg_n += sizeof(long);
            envs = arg_n;
            for (int i = 0; i < envc; i++) {
                arg_n = arg_n + strlen(arg_n) + 1;
            }
            if (request_header.cmd == LAUNCHER_KWRAPPER) {
                tty = arg_n;
                arg_n += strlen(tty) + 1;
            }
        }

        if (request_header.cmd == LAUNCHER_SHELL || request_header.cmd == LAUNCHER_KWRAPPER
                || request_header.cmd == LAUNCHER_EXT_EXEC || request_header.cmd == LAUNCHER_EXEC_NEW) {
            memcpy(&l, arg_n, sizeof(long));
            avoid_loops = l;
            arg_n += sizeof(long);
        }

        if (request_header.cmd == LAUNCHER_SHELL || request_header.cmd == LAUNCHER_KWRAPPER
                || request_header.cmd == LAUNCHER_EXT_EXEC) {
            startup_id_str = arg_n;
            arg_n += strlen(startup_id_str) + 1;
        }

        if ((request_header.arg_length > (arg_n - request_data)) &&
                (request_header.cmd == LAUNCHER_EXT_EXEC || request_header.cmd == LAUNCHER_EXEC_NEW)) {
            // Optional cwd
            cwd = arg_n; arg_n += strlen(cwd) + 1;
        }

        if ((arg_n - request_data) != request_header.arg_length) {
#ifndef NDEBUG
            fprintf(stderr, "kdeinit5: EXEC request has invalid format.\n");
#endif
            free(request_data);
            d.debug_wait = false;
            return true; // sure?
        }

        // support for the old a bit broken way of setting DISPLAY for multihead
        QByteArray olddisplay = qgetenv(displayEnvVarName().constData());
        QByteArray kdedisplay = qgetenv("KDE_DISPLAY");
        bool reset_display = (! olddisplay.isEmpty() &&
                              ! kdedisplay.isEmpty() &&
                              olddisplay != kdedisplay);

        if (reset_display) {
            qputenv(displayEnvVarName().constData(), kdedisplay);
        }

        pid = launch(argc, name, args, cwd, envc, envs,
                     request_header.cmd == LAUNCHER_SHELL || request_header.cmd == LAUNCHER_KWRAPPER,
                     tty, avoid_loops, startup_id_str);

        if (reset_display) {
            unsetenv("KDE_DISPLAY");
            qputenv(displayEnvVarName().constData(), olddisplay);
        }

        if (pid && (d.result == 0)) {
            response_header.cmd = LAUNCHER_OK;
            response_header.arg_length = sizeof(response_data);
            response_data = pid;
            write(sock, &response_header, sizeof(response_header));
            write(sock, &response_data, response_header.arg_length);

            /* add new child to list */
            struct child *child = (struct child *) malloc(sizeof(struct child));
            child->pid = pid;
            child->sock = dup(sock);
            child->next = children;
            children = child;
        } else {
            int l = d.errorMsg.length();
            if (l) {
                l++;    // Include trailing null.
            }
            response_header.cmd = LAUNCHER_ERROR;
            response_header.arg_length = l;
            write(sock, &response_header, sizeof(response_header));
            if (l) {
                write(sock, d.errorMsg.data(), l);
            }
        }
        d.debug_wait = false;
    } else if (request_header.arg_length && request_header.cmd == LAUNCHER_SETENV) {
        const char *env_name;
        const char *env_value;
        env_name = request_data;
        env_value = env_name + strlen(env_name) + 1;

#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: Got SETENV '%s=%s' from %s.\n", env_name, env_value, who);
#endif

        if (request_header.arg_length !=
                (int)(strlen(env_name) + strlen(env_value) + 2)) {
#ifndef NDEBUG
            fprintf(stderr, "kdeinit5: SETENV request has invalid format.\n");
#endif
            free(request_data);
            return true; // sure?
        }
        qputenv(env_name, env_value);
    } else if (request_header.cmd == LAUNCHER_TERMINATE_KDE) {
#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: terminate KDE.\n");
#endif
#if HAVE_X11
        kdeinit_xio_errhandler(0L);
#endif
    } else if (request_header.cmd == LAUNCHER_TERMINATE_KDEINIT) {
#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: Got termination request (PID %ld).\n", (long) getpid());
#endif
        if (d.launcher_pid) {
            kill(d.launcher_pid, SIGTERM);
            d.launcher_pid = 0;
            close(d.launcher[0]);
            d.launcher[0] = -1;
        }
        unlink(sock_file);
        if (children) {
            close(d.wrapper);
            d.wrapper = -1;
#ifndef NDEBUG
            fprintf(stderr, "kdeinit5: Closed sockets, but not exiting until all children terminate.\n");
#endif
        } else {
            raise(SIGTERM);
        }
    } else if (request_header.cmd == LAUNCHER_DEBUG_WAIT) {
#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: Debug wait activated.\n");
#endif
        d.debug_wait = true;
    }
    if (request_data) {
        free(request_data);
    }
    return true;
}

static void handle_requests(pid_t waitForPid)
{
    int max_sock = d.deadpipe[0];
    if (d.wrapper > max_sock) {
        max_sock = d.wrapper;
    }
    if (d.launcher[0] > max_sock) {
        max_sock = d.launcher[0];
    }
#if HAVE_X11
    if (X11fd > max_sock) {
        max_sock = X11fd;
    }
#endif
    max_sock++;

    while (1) {
        fd_set rd_set;
        fd_set wr_set;
        fd_set e_set;
        int result;
        pid_t exit_pid;
        int exit_status;
        char c;

        /* Flush the pipe of death */
        while (read(d.deadpipe[0], &c, 1) == 1) {
        }

        /* Handle dying children */
        do {
            exit_pid = waitpid(-1, &exit_status, WNOHANG);
            if (exit_pid > 0) {
#ifndef NDEBUG
                fprintf(stderr, "kdeinit5: PID %ld terminated.\n", (long) exit_pid);
#endif
                if (waitForPid && (exit_pid == waitForPid)) {
                    return;
                }

                if (WIFEXITED(exit_status)) { // fix process return value
                    exit_status = WEXITSTATUS(exit_status);
                } else if (WIFSIGNALED(exit_status)) {
                    exit_status = 128 + WTERMSIG(exit_status);
                }
                child_died(exit_pid, exit_status);

                if (d.wrapper < 0 && !children) {
#ifndef NDEBUG
                    fprintf(stderr, "kdeinit5: Last child terminated, exiting (PID %ld).\n",
                            (long) getpid());
#endif
                    raise(SIGTERM);
                }
            }
        } while (exit_pid > 0);

        FD_ZERO(&rd_set);
        FD_ZERO(&wr_set);
        FD_ZERO(&e_set);

        if (d.launcher[0] >= 0) {
            FD_SET(d.launcher[0], &rd_set);
        }
        if (d.wrapper >= 0) {
            FD_SET(d.wrapper, &rd_set);
        }
        FD_SET(d.deadpipe[0], &rd_set);
#if HAVE_X11
        if (X11fd >= 0) {
            FD_SET(X11fd, &rd_set);
        }
#endif

        result = select(max_sock, &rd_set, &wr_set, &e_set, 0);
        if (result < 0) {
            if (errno == EINTR || errno == EAGAIN) {
                continue;
            }
            perror("kdeinit5: Aborting. select() failed");
            return;
        }

        /* Handle wrapper request */
        if (d.wrapper >= 0 && FD_ISSET(d.wrapper, &rd_set)) {
            struct sockaddr_un client;
            kde_socklen_t sClient = sizeof(client);
            int sock = accept(d.wrapper, (struct sockaddr *)&client, &sClient);
            if (sock >= 0) {
                d.accepted_fd = sock;
                handle_launcher_request(sock, "wrapper");
                close(sock);
                d.accepted_fd = -1;
            }
        }

        /* Handle launcher request */
        if (d.launcher[0] >= 0 && FD_ISSET(d.launcher[0], &rd_set)) {
            if (!handle_launcher_request(d.launcher[0], "launcher")) {
                launcher_died();
            }
            if (waitForPid == d.launcher_pid) {
                return;
            }
        }

#if HAVE_X11
        /* Look for incoming X11 events */
        if (X11fd >= 0 && FD_ISSET(X11fd, &rd_set)) {
            if (X11display != 0) {
                XEvent event_return;
                while (XPending(X11display)) {
                    XNextEvent(X11display, &event_return);
                }
            }
        }
#endif
    }
}

static void kdeinit_library_path()
{

    const QStringList ltdl_library_path =
        QFile::decodeName(qgetenv("LTDL_LIBRARY_PATH")).split(QLatin1Char(':'), QString::SkipEmptyParts);
#ifdef Q_OS_DARWIN
    const QByteArray ldlibpath = qgetenv("DYLD_LIBRARY_PATH");
#else
    const QByteArray ldlibpath = qgetenv("LD_LIBRARY_PATH");
#endif
    const QStringList ld_library_path =
        QFile::decodeName(ldlibpath).split(QLatin1Char(':'), QString::SkipEmptyParts);

#if 0 // unused

    QByteArray extra_path;
    const QStringList candidates = s_instance->dirs()->resourceDirs("lib");
    for (QStringList::ConstIterator it = candidates.begin();
            it != candidates.end();
            ++it) {
        QString d = *it;
        if (ltdl_library_path.contains(d)) {
            continue;
        }
        if (ld_library_path.contains(d)) {
            continue;
        }
        if (d[d.length() - 1] == QLatin1Char('/')) {
            d.truncate(d.length() - 1);
            if (ltdl_library_path.contains(d)) {
                continue;
            }
            if (ld_library_path.contains(d)) {
                continue;
            }
        }
        if ((d == QLatin1String("/lib")) || (d == QLatin1String("/usr/lib"))) {
            continue;
        }

        QByteArray dir = QFile::encodeName(d);

        if (access(dir, R_OK)) {
            continue;
        }

        if (!extra_path.isEmpty()) {
            extra_path += ':';
        }
        extra_path += dir;
    }
#endif

//   if (!extra_path.isEmpty())
//      lt_dlsetsearchpath(extra_path.data());

    QByteArray display = qgetenv(displayEnvVarName().constData());
    if (display.isEmpty()) {
#if HAVE_X11 // qt5: see displayEnvVarName()
        fprintf(stderr, "kdeinit5: Aborting. $%s is not set. \n", displayEnvVarName().constData());
        exit(255);
#endif
    }
    int i;
    if ((i = display.lastIndexOf('.')) > display.lastIndexOf(':') && i >= 0) {
        display.truncate(i);
    }

    display.replace(':', '_');
#ifdef __APPLE__
    display.replace('/', '_');
#endif
    // WARNING, if you change the socket name, adjust kwrapper too
    const QString socketFileName = QString::fromLatin1("kdeinit5_%1").arg(QLatin1String(display));
    QByteArray socketName = QFile::encodeName(QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation) + QLatin1Char('/') + socketFileName);
    if (socketName.length() >= MAX_SOCK_FILE) {
        fprintf(stderr, "kdeinit5: Aborting. Socket name will be too long:\n");
        fprintf(stderr, "         '%s'\n", socketName.data());
        exit(255);
    }
    strcpy(sock_file, socketName.data());
}

#if HAVE_X11
int kdeinit_xio_errhandler(Display *disp)
{
    // disp is 0L when KDE shuts down. We don't want those warnings then.

    if (disp) {
        qWarning("kdeinit5: Fatal IO error: client killed");
    }

    if (sock_file[0]) {
        /** Delete any stale socket file **/
        unlink(sock_file);
    }

    // Don't kill our children in suicide mode, they may still be in use
    if (d.suicide) {
        if (d.launcher_pid) {
            kill(d.launcher_pid, SIGTERM);
        }
        if (d.kded_pid) {
            kill(d.kded_pid, SIGTERM);
        }
        exit(0);
    }

    if (disp) {
        qWarning("kdeinit5: sending SIGHUP to children.");
    }

    /* this should remove all children we started */
    signal(SIGHUP, SIG_IGN);
    kill(0, SIGHUP);

    sleep(2);

    if (disp) {
        qWarning("kdeinit5: sending SIGTERM to children.");
    }

    /* and if they don't listen to us, this should work */
    signal(SIGTERM, SIG_IGN);
    kill(0, SIGTERM);

    if (disp) {
        qWarning("kdeinit5: Exit.");
    }

    exit(0);
    return 0;
}

int kdeinit_x_errhandler(Display *dpy, XErrorEvent *err)
{
#ifndef NDEBUG
    char errstr[256];
    // kdeinit almost doesn't use X, and therefore there shouldn't be any X error
    XGetErrorText(dpy, err->error_code, errstr, 256);
    fprintf(stderr, "kdeinit5(%d) : KDE detected X Error: %s %d\n"
            "         Major opcode: %d\n"
            "         Minor opcode: %d\n"
            "         Resource id:  0x%lx\n",
            getpid(), errstr, err->error_code, err->request_code, err->minor_code, err->resourceid);

#else
    Q_UNUSED(dpy);
    Q_UNUSED(err);
#endif
    return 0;
}
#endif

#if HAVE_X11
// needs to be done sooner than initXconnection() because of also opening
// another X connection for startup notification purposes
static void setupX()
{
    XSetIOErrorHandler(kdeinit_xio_errhandler);
    XSetErrorHandler(kdeinit_x_errhandler);
    /*
        Handle the tricky case of running via kdesu/su/sudo/etc. There the usual case
        is that kdesu (etc.) creates a file with xauth information, sets XAUTHORITY,
        runs the command and removes the xauth file after the command finishes. However,
        dbus and kdeinit daemon currently don't clean up properly and keeping running.
        Which means that running a KDE app via kdesu the second time talks to kdeinit
        with obsolete xauth information, which makes it unable to connect to X or launch
        any X11 applications.
        Even fixing the cleanup probably wouldn't be sufficient, since it'd be possible to
        launch one kdesu session, another one, exit the first one and the app from the second
        session would be using kdeinit from the first one.
        So the trick here is to duplicate the xauth file to another file in KDE's tmp
        location, make the file have a consistent name so that future sessions will use it
        as well, point XAUTHORITY there and never remove the file (except for possible
        tmp cleanup).
    */
    if (!qgetenv("XAUTHORITY").isEmpty()) {
        QByteArray display = qgetenv(displayEnvVarName().constData());
        int i;
        if ((i = display.lastIndexOf('.')) > display.lastIndexOf(':') && i >= 0) {
            display.truncate(i);
        }
        display.replace(':', '_');
#ifdef __APPLE__
        display.replace('/', '_');
#endif
        QString xauth = QDir::tempPath() + QLatin1String("/xauth-")
                        + QString::number(getuid()) + QLatin1String("-") + QString::fromLocal8Bit(display);
        QSaveFile xauthfile(xauth);
        QFile xauthfrom(QFile::decodeName(qgetenv("XAUTHORITY")));
        if (!xauthfrom.open(QFile::ReadOnly) || !xauthfile.open(QFile::WriteOnly)
                || xauthfile.write(xauthfrom.readAll()) != xauthfrom.size() || !xauthfile.commit()) {
            // error
        } else {
            qputenv("XAUTHORITY", QFile::encodeName(xauth));
        }
    }
}

// Borrowed from kdebase/kaudio/kaudioserver.cpp
static int initXconnection()
{
    X11display = XOpenDisplay(NULL);
    if (X11display != 0) {
        XCreateSimpleWindow(X11display, DefaultRootWindow(X11display), 0, 0, 1, 1, \
                            0,
                            BlackPixelOfScreen(DefaultScreenOfDisplay(X11display)),
                            BlackPixelOfScreen(DefaultScreenOfDisplay(X11display)));
#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: opened connection to %s\n", DisplayString(X11display));
#endif
        int fd = XConnectionNumber(X11display);
        int on = 1;
        (void) setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char *) &on, (int) sizeof(on));
        return fd;
    } else
        fprintf(stderr, "kdeinit5: Can not connect to the X Server.\n" \
                "kdeinit5: Might not terminate at end of session.\n");

    return -1;
}
#endif

// Find a shared lib in the lib dir, e.g. libkio.so.
// Completely unrelated to plugins.
static QString findSharedLib(const QString &lib)
{
    QString path = QFile::decodeName(CMAKE_INSTALL_PREFIX "/" LIB_INSTALL_DIR "/") + lib;
    if (QFile::exists(path)) {
        return path;
    }
    // We could also look in LD_LIBRARY_PATH, but really, who installs the main libs in different prefixes?
    return QString();
}

#ifdef Q_OS_MAC
/**
 Calling CoreFoundation APIs (which is unavoidable in Qt/Mac) has always had issues
 on Mac OS X, but as of 10.5 is explicitly disallowed with an exception.  As a
 result, in the case where we would normally fork and then dlopen code, or continue
 to run other code, we must now fork-and-exec.

 See "CoreFoundation and fork()" at http://developer.apple.com/releasenotes/CoreFoundation/CoreFoundation.html
*/
// Copied from kkernel_mac.cpp
void
mac_fork_and_reexec_self()
{
    int argc = *_NSGetArgc();
    char **argv = *_NSGetArgv();
    char *newargv[argc + 2];
    char progname[PATH_MAX];
    uint32_t buflen = PATH_MAX;
    _NSGetExecutablePath(progname, &buflen);
    bool found_psn = false;

    for (int i = 0; i < argc; i++) {
        newargv[i] = argv[i];
    }

    newargv[argc] = "--nofork";
    newargv[argc + 1] = NULL;

    int x_fork_result = fork();
    switch (x_fork_result) {

    case -1:
#ifndef NDEBUG
        fprintf(stderr, "Mac OS X workaround fork() failed!\n");
#endif
        ::_exit(255);
        break;

    case 0:
        // Child
        execvp(progname, newargv);
        break;

    default:
        // Parent
        _exit(0);
        break;

    }
}
#endif

extern "C" {

    static void secondary_child_handler(int)
    {
        waitpid(-1, 0, WNOHANG);
    }

}

int main(int argc, char **argv, char **envp)
{
#ifndef _WIN32_WCE
    setlocale(LC_ALL, "");
    setlocale(LC_NUMERIC, "C");
#endif

    pid_t pid;
    bool do_fork = true;
    int launch_klauncher = 1;
    // KDE5 TODO: make this 0 by default, so that a random kde app doesn't start kded5 upfront,
    // but on demand when a service needs it. In startkde, however, use +kded5 or --kded.
    // (+kded5 might not work because it doesn't fork on startup anymore)
    int launch_kded = 1;
    int keep_running = 1;
    d.suicide = false;

    /** Save arguments first... **/
    char **safe_argv = (char **) malloc(sizeof(char *) * argc);
    for (int i = 0; i < argc; i++) {
        safe_argv[i] = strcpy((char *)malloc(strlen(argv[i]) + 1), argv[i]);
        if (strcmp(safe_argv[i], "--no-klauncher") == 0) {
            launch_klauncher = 0;
        }
        if (strcmp(safe_argv[i], "--no-kded") == 0) {
            launch_kded = 0;
        }
#ifdef Q_OS_MAC
        // make it nofork to match KUniqueApplication, technically command-line incompatible
        if (strcmp(safe_argv[i], "--nofork") == 0)
#else
        if (strcmp(safe_argv[i], "--no-fork") == 0)
#endif
            do_fork = false;
        if (strcmp(safe_argv[i], "--suicide") == 0) {
            d.suicide = true;
        }
        if (strcmp(safe_argv[i], "--exit") == 0) {
            keep_running = 0;
        }
        if (strcmp(safe_argv[i], "--version") == 0) {
            printf("Qt: %s\n", qVersion());
            printf("KDE: %s\n", KINIT_VERSION_STRING);
            exit(0);
        }
#if KDEINIT_OOM_PROTECT
        if (strcmp(safe_argv[i], "--oom-pipe") == 0 && i + 1 < argc) {
            oom_pipe = atol(argv[i + 1]);
        }
#endif
        if (strcmp(safe_argv[i], "--help") == 0) {
            printf("Usage: kdeinit5 [options]\n");
#ifdef Q_OS_MAC
            printf("    --nofork          Do not fork\n");
#else
            printf("    --no-fork         Do not fork\n");
#endif
            // printf("    --no-klauncher    Do not start klauncher\n");
            printf("    --no-kded         Do not start kded\n");
            printf("    --suicide         Terminate when no KDE applications are left running\n");
            printf("    --version         Show version information\n");
            // printf("    --exit            Terminate when kded has run\n");
            exit(0);
        }
    }

    cleanup_fds();

    // Redirect stdout to stderr. We have no reason to use stdout anyway.
    // This minimizes our impact on commands used in pipes.
    (void)dup2(2, 1);

    if (do_fork) {
#ifdef Q_OS_MAC
        mac_fork_and_reexec_self();
#else
        if (pipe(d.initpipe) != 0) {
            perror("kdeinit5: pipe failed");
            return 1;
        }

        // Fork here and let parent process exit.
        // Parent process may only exit after all required services have been
        // launched. (dcopserver/klauncher and services which start with '+')
        signal(SIGCHLD, secondary_child_handler);
        if (fork() > 0) { // Go into background
            close(d.initpipe[1]);
            d.initpipe[1] = -1;
            // wait till init is complete
            char c;
            while (read(d.initpipe[0], &c, 1) < 0)
                ;
            // then exit;
            close(d.initpipe[0]);
            d.initpipe[0] = -1;
            return 0;
        }
        close(d.initpipe[0]);
        d.initpipe[0] = -1;
#endif
    }

    /** Make process group leader (for shutting down children later) **/
    if (keep_running) {
        setsid();
    }

    /** Prepare to change process name **/
#ifndef SKIP_PROCTITLE
    proctitle_init(argc, argv, envp);
#endif

    kdeinit_library_path();
    // don't change envvars before proctitle_init()
    unsetenv("LD_BIND_NOW");
    unsetenv("DYLD_BIND_AT_LAUNCH");
    KCrash::loadedByKdeinit = true;

    d.maxname = strlen(argv[0]);
    d.launcher_pid = 0;
    d.kded_pid = 0;
    d.wrapper = -1;
    d.accepted_fd = -1;
    d.debug_wait = false;
    d.launcher_ok = false;
    children = NULL;
    init_signals();
#if HAVE_X11
    setupX();
#endif

    if (keep_running) {
        /*
         * Create ~/.kde/tmp-<hostname>/kdeinit5-<display> socket for incoming wrapper
         * requests.
         */
        init_kdeinit_socket();
    }
#ifdef Q_OS_UNIX
    if (!d.suicide && qgetenv("KDE_IS_PRELINKED").isEmpty()) {
        const int extrasCount = sizeof(extra_libs) / sizeof(extra_libs[0]);
        for (int i = 0; i < extrasCount; i++) {
            const QString extra = findSharedLib(QString::fromLatin1(extra_libs[i]));
            if (!extra.isEmpty()) {
                QLibrary l(extra);
                l.setLoadHints(QLibrary::ExportExternalSymbolsHint);
                (void)l.load();
            }
#ifndef NDEBUG
            else {
                fprintf(stderr, "%s was not found.\n", extra_libs[i]);
            }
#endif

        }
    }
#endif
    if (launch_klauncher) {
        start_klauncher();
        handle_requests(d.launcher_pid); // Wait for klauncher to be ready
    }

#if HAVE_X11
    X11fd = initXconnection();
#endif

    {
        QFont::initialize();
#if HAVE_X11
        if (XSupportsLocale()) {
            // Similar to QApplication::create_xim()
            // but we need to use our own display
            XOpenIM(X11display, 0, 0, 0);
        }
#endif
    }

    if (launch_kded) {
        qputenv("KDED_STARTED_BY_KDEINIT", "1");
        pid = launch(1, KDED_EXENAME, 0);
        unsetenv("KDED_STARTED_BY_KDEINIT");
#ifndef NDEBUG
        fprintf(stderr, "kdeinit5: Launched KDED, pid = %ld result = %d\n", (long) pid, d.result);
#endif
        d.kded_pid = pid;
        // kded5 doesn't fork on startup anymore, so just move on.
        //handle_requests(pid);
    }

    for (int i = 1; i < argc; i++) {
        if (safe_argv[i][0] == '+') {
            pid = launch(1, safe_argv[i] + 1, 0);
#ifndef NDEBUG
            fprintf(stderr, "kdeinit5: Launched '%s', pid = %ld result = %d\n", safe_argv[i] + 1, (long) pid, d.result);
#endif
            handle_requests(pid);
        } else if (safe_argv[i][0] == '-'
#if KDEINIT_OOM_PROTECT
                   || isdigit(safe_argv[i][0])
#endif
                  ) {
            // Ignore
        } else {
            pid = launch(1, safe_argv[i], 0);
#ifndef NDEBUG
            fprintf(stderr, "kdeinit5: Launched '%s', pid = %ld result = %d\n", safe_argv[i], (long) pid, d.result);
#endif
        }
    }

    /** Free arguments **/
    for (int i = 0; i < argc; i++) {
        free(safe_argv[i]);
    }
    free(safe_argv);

#ifndef SKIP_PROCTITLE
    proctitle_set("kdeinit5 Running...");
#endif

    if (!keep_running) {
        return 0;
    }

    if (d.initpipe[1] != -1) {
        char c = 0;
        write(d.initpipe[1], &c, 1); // Kdeinit is started.
        close(d.initpipe[1]);
        d.initpipe[1] = -1;
    }

    handle_requests(0);

    return 0;
}

