# /usr/share/dbus-1/system-services/org.example.MyService.service
[D-BUS Service]
Name=org.example.MyService
Exec=/usr/bin/my-service
User=root
SystemdService=my-service.service

# /etc/systemd/system/my-service.service
[Unit]
Description=My D-Bus Service
After=network.target

[Service]
Type=dbus
BusName=org.example.MyService
ExecStart=/usr/bin/my-service
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

# /usr/share/dbus-1/system-services/org.example.MyService.service
[D-BUS Service]
Name=org.example.MyService
SystemdService=my-service.service

<!-- /usr/share/dbus-1/system.d/org.example.MyService.conf -->
<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <policy user="root">
    <allow own="org.example.MyService"/>
  </policy>
  <policy context="default">
    <allow send_destination="org.example.MyService"/>
  </policy>
</busconfig>

# 启用并启动服务
sudo systemctl daemon-reload
sudo systemctl enable my-service
sudo systemctl start my-service

# 验证状态
systemctl status my-service

# 测试 D-Bus 激活
# 先停止服务
sudo systemctl stop my-service

# 通过 D-Bus 调用会自动启动服务
busctl call org.example.MyService /org/example org.example.Interface Ping

[Service]
Type=dbus
BusName=org.example.MyService
ExecStart=/usr/bin/my-service

# 可选：设置总线名称获取超时
TimeoutSec=30

# 检查 BusName 是否已被获取
busctl list | grep org.example.MyService

# systemd 属性检查
systemctl show my-service -p BusName

# ~/.config/systemd/user/my-app.service
[Unit]
Description=My User D-Bus Service

[Service]
Type=dbus
BusName=org.example.MyApp
ExecStart=/usr/local/bin/my-app
Restart=on-failure

[Install]
WantedBy=default.target

# 启用用户服务
systemctl --user enable my-app

# 启动
systemctl --user start my-app

# 查看状态
systemctl --user status my-app

# 查看日志
journalctl --user -u my-app

# 用户服务的 Session Bus 激活文件
# ~/.local/share/dbus-1/services/org.example.MyApp.service

# ~/.local/share/dbus-1/services/org.example.MyApp.service
[D-BUS Service]
Name=org.example.MyApp
SystemdService=my-app.service

# /etc/systemd/system/my-db-service.socket
[Unit]
Description=My D-Bus Service Socket

[Socket]
ListenStream=/run/my-service.sock

[Install]
WantedBy=sockets.target

# /etc/systemd/system/my-db-service.service
[Unit]
Description=My D-Bus Service
Requires=my-db-service.socket

[Service]
Type=dbus
BusName=org.example.MyService
ExecStart=/usr/bin/my-service

# /usr/share/dbus-1/system-services/org.example.MyService.service
[D-BUS Service]
Name=org.example.MyService
SystemdService=my-service.service

#include <systemd/sd-daemon.h>
#include <stdio.h>

int main(void) {
    int n = sd_listen_fds(0);
    
    if (n > 0) {
        printf("从 systemd 接收了 %d 个套接字\n", n);
        int fd = SD_LISTEN_FDS_START;  // 第一个套接字的 fd
        
        // 使用 fd 进行通信
        // ...
    } else {
        printf("没有从 systemd 接收套接字\n");
    }
    
    return 0;
}

#include <systemd/sd-bus.h>
#include <stdio.h>

int main(void) {
    sd_bus *bus = NULL;
    sd_bus_error error = SD_BUS_ERROR_NULL;
    sd_bus_message *reply = NULL;
    int r;
    
    /* 连接到 System Bus */
    r = sd_bus_open_system(&bus);
    if (r < 0) {
        fprintf(stderr, "连接 System Bus 失败: %s\n", strerror(-r));
        return 1;
    }
    
    /* 调用方法 */
    r = sd_bus_call_method(
        bus,
        "org.freedesktop.systemd1",       /* dest */
        "/org/freedesktop/systemd1",      /* path */
        "org.freedesktop.systemd1.Manager", /* interface */
        "ListUnits",                       /* method */
        &error,
        &reply,
        ""                                 /* 签名 (无参数) */
    );
    
    if (r < 0) {
        fprintf(stderr, "调用失败: %s\n", error.message);
        sd_bus_error_free(&error);
        return 1;
    }
    
    /* 解析回复 */
    const char *name, *description, *load_state, *active_state;
    uint32_t pid;
    
    r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "(ssssssouso)");
    if (r >= 0) {
        printf("systemd 单元列表:\n");
        while ((r = sd_bus_message_read(reply, "(ssssssouso)",
                &name, &description, &load_state, &active_state,
                NULL, NULL, NULL, &pid, NULL, NULL)) > 0) {
            printf("  %-40s %-15s %s\n", name, active_state, description);
        }
        sd_bus_message_exit_container(reply);
    }
    
    sd_bus_message_unref(reply);
    sd_bus_unref(bus);
    return 0;
}

gcc -o sd-bus-example sd-bus-example.c -lsystemd

/* 读取 systemd 的 Version 属性 */
sd_bus_message *reply;
sd_bus_error error = SD_BUS_ERROR_NULL;

r = sd_bus_call_method(
    bus,
    "org.freedesktop.systemd1",
    "/org/freedesktop/systemd1",
    "org.freedesktop.DBus.Properties",
    "Get",
    &error,
    &reply,
    "ss",
    "org.freedesktop.systemd1.Manager",
    "Version"
);

if (r >= 0) {
    const char *version;
    sd_bus_message_enter_container(reply, SD_BUS_TYPE_VARIANT, "s");
    sd_bus_message_read(reply, "s", &version);
    printf("systemd 版本: %s\n", version);
    sd_bus_message_exit_container(reply);
    sd_bus_message_unref(reply);
}

#include <systemd/sd-bus.h>
#include <systemd/sd-event.h>

static int on_unit_new(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
    const char *id, *path;
    sd_bus_message_read(m, "so", &id, &path);
    printf("新单元: %s (%s)\n", id, path);
    return 0;
}

int main(void) {
    sd_bus *bus = NULL;
    sd_event *event = NULL;
    
    sd_bus_open_system(&bus);
    sd_event_default(&event);
    
    sd_bus_attach_event(bus, event, 0);
    
    /* 订阅 UnitNew 信号 */
    sd_bus_match_signal(
        bus,
        NULL,
        "org.freedesktop.systemd1",
        "/org/freedesktop/systemd1",
        "org.freedesktop.systemd1.Manager",
        "UnitNew",
        on_unit_new,
        NULL
    );
    
    /* 运行事件循环 */
    sd_event_run(event, (uint64_t)-1);
    
    sd_bus_unref(bus);
    sd_event_unref(event);
    return 0;
}

gcc -o sd-bus-signals sd-bus-signals.c -lsystemd

# 查看 systemd 版本
busctl get-property org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  Version

# 列出所有单元
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  ListUnits

# 获取特定单元状态
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  GetUnit \
  s "dbus.service"

# 启动服务
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  StartUnit \
  ss "my-service.service" "replace"

# 停止服务
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  StopUnit \
  ss "my-service.service" "replace"

# 重启服务
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  RestartUnit \
  ss "my-service.service" "replace"

# 查看单元属性
busctl call org.freedesktop.systemd1 \
  /org/freedesktop/systemd1 \
  org.freedesktop.systemd1.Manager \
  GetUnit \
  s "dbus.service"

# 获取单元的所有属性
busctl get-property org.freedesktop.systemd1 \
  /org/freedesktop/systemd1/unit/dbus_2eservice \
  org.freedesktop.systemd1.Unit \
  --all

#!/usr/bin/env python3
"""通过 D-Bus 管理 systemd 服务"""

import dbus

bus = dbus.SystemBus()

# 获取 systemd 代理
systemd = bus.get_object(
    'org.freedesktop.systemd1',
    '/org/freedesktop/systemd1'
)
manager = dbus.Interface(systemd, 'org.freedesktop.systemd1.Manager')

# 列出活跃服务
units = manager.ListUnits()
print("活跃服务:")
for name, desc, load, active, sub, job_type, job_path, job_id, job_obj_path, follows in units:
    if active == 'active' and sub == 'running':
        print(f"  ✅ {name}: {desc}")

# 启动服务
try:
    job_path = manager.StartUnit('nginx.service', 'replace')
    print(f"启动作业: {job_path}")
except dbus.exceptions.DBusException as e:
    print(f"启动失败: {e}")

# 获取服务状态
props = dbus.Interface(systemd, 'org.freedesktop.DBus.Properties')
unit_path = manager.GetUnit('dbus.service')
unit = bus.get_object('org.freedesktop.systemd1', unit_path)
unit_props = dbus.Interface(unit, 'org.freedesktop.DBus.Properties')

active_state = unit_props.Get('org.freedesktop.systemd1.Unit', 'ActiveState')
print(f"\ndbus.service 状态: {active_state}")

# 查看当前会话
busctl call org.freedesktop.login1 \
  /org/freedesktop/login1 \
  org.freedesktop.login1.Manager \
  ListSessions

# 锁屏
busctl call org.freedesktop.login1 \
  /org/freedesktop/login1 \
  org.freedesktop.login1.Manager \
  LockSession \
  s "auto"

# 查询能力
busctl call org.freedesktop.login1 \
  /org/freedesktop/login1 \
  org.freedesktop.login1.Manager \
  CanPowerOff

# 注销当前会话
busctl call org.freedesktop.login1 \
  /org/freedesktop/login1 \
  org.freedesktop.login1.Manager \
  TerminateSession \
  s "auto"