smart-os/xfce4.md
2022-08-19 08:57:22 +08:00

313 lines
21 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# xfce4 组件介绍
* [ Gtk+ ] 这些组件 gtk 最庞大
libffi
libmount
glib
pixman
freetype
harfbuzz
fontconfig
cairo
fribidi
pango
gdkpixbuf
libeproxy
graphene
wayland-protocols
gettext( libintl )
gtk+
* [ xfce ] 这些组件编译顺序也有要求
libwnck
xfce4-dev-tools
xlibxfce4util
xfconf
libxfce4ui
garcon
exo
xfce4-panel
thunar
xfce4-settings
xfce4-session
xfwm4
xfdesktop
thunar-volman
tumbler
xfce4-power-manager
xfce4-appfinder
# Cairo
cairo is a vector graphics library with cross-device output support
cairo能够做各种复杂的点线图案绘制、填充、文字渲染、图像变换、剪切、层混合等等操作。但是他没有涉及到用户交互如鼠标、touch、事件处理交互窗口这些统统没有他只有专一的绘图。他有surface可以理解为画布这个surface可以是基于内存image surface必选的surface也可以基于某种backend和操作系统或驱动接口对接使用过程是创建一个surface然后在surface里做各种绘图最后使用Painting类的functions时图像就显示在了surface上。当然surface也是一块image可以把image通过png源码有对接libpng库图像压缩输出png文件
# harfbuzz
HarfBuzz 是一个文本整形引擎。它主要支持OpenType但也 支持Apple Advanced Typography。HarfBuzz 用于 Android、Chrome、ChromeOS、Firefox、GNOME、GTK+、KDE、LibreOffice、OpenJDK、PlayStation、Qt、XeTeX 等地方。
# xfce 运行黑屏怎么办
比如黑屏,我们由屏幕想到可能是 xfdesktop 这个应用负责渲屏,黑屏可能是 xfdesktop 未能正确运行,这个就需要我们手工调试跟踪了,通常情况下我们会这么做:
```shell
# 设置屏幕,这个是 xfce 默认的值 10
export DISPLAY=:10
# 执行这个,正常执行理论上就不会黑屏,不能执行,可能是依赖库路径不对,版本不对,配置不对,逐步根据提示解决问题
xfdesktop
```
# xrdp 远程访问 linux 桌面流程分析( 重要
1. xrdp 服务依赖 xrdp-sesman 服务
我们可以通过 grep 全局查找 xrdp-sesman发现下面这句
```shell
./lib/systemd/system/xrdp.service:4:Requires=xrdp-sesman.service
```
因此 xrdp 启动时,肯定 xrdp-sesman 也相应启动,具体机制待研究(TODO)
2. 配置文件 /etc/xrdp/sesman.ini
```shell
[Globals]
ListenAddress=127.0.0.1
ListenPort=3350
```
3. 确认 xrdp 和 xrdp-sesman 服务
```shell
root@freeabc:/# netstat -anpt | grep xrdp
tcp6 0 0 :::3389 :::* LISTEN 6288/xrdp
tcp6 0 0 ::1:3350 :::* LISTEN 6259/xrdp-sesman
```
其中 xrdp 是 3389 对外提供服务, xrdp-sesman 是 3350 对 xrdp 提供服务xrdp 把请求转给 xrdp-sesman (经过 tcpdump 抓包确认是)
```shell
root@freeabc:/# tcpdump -s 0 -i lo port 3350 -v -n
tcpdump: listening on lo, link-type EN10MB (Ethernet), capture size 262144 bytes
01:37:24.538435 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 40) ::1.52600 > ::1.3350: Flags [S], cksum 0x0030 (incorrect -> 0x3f1d), seq 213438096, win 65476, options [mss 65476,sackOK,TS val 4262615841 ecr 0,nop,wscale 7], length 0
01:37:24.538457 IP6 (flowlabel 0xe10b3, hlim 64, next-header TCP (6) payload length: 40) ::1.3350 > ::1.52600: Flags [S.], cksum 0x0030 (incorrect -> 0xbea4), seq 3363004107, ack 213438097, win 65464, options [mss 65476,sackOK,TS val 4262615841 ecr 4262615841,nop,wscale 7], length 0
01:37:24.538472 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 32) ::1.52600 > ::1.3350: Flags [.], cksum 0x0028 (incorrect -> 0xe53a), ack 1, win 512, options [nop,nop,TS val 4262615841 ecr 4262615841], length 0
01:37:25.149700 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 109) ::1.52600 > ::1.3350: Flags [P.], cksum 0x0075 (incorrect -> 0x6a7f), seq 1:78, ack 1, win 512, options [nop,nop,TS val 4262616452 ecr 4262615841], length 77
01:37:25.149734 IP6 (flowlabel 0xe10b3, hlim 64, next-header TCP (6) payload length: 32) ::1.3350 > ::1.52600: Flags [.], cksum 0x0028 (incorrect -> 0xe028), ack 78, win 511, options [nop,nop,TS val 4262616452 ecr 4262616452], length 0
01:37:25.216918 IP6 (flowlabel 0xe10b3, hlim 64, next-header TCP (6) payload length: 62) ::1.3350 > ::1.52600: Flags [P.], cksum 0x0046 (incorrect -> 0xd13d), seq 1:31, ack 78, win 512, options [nop,nop,TS val 4262616519 ecr 4262616452], length 30
01:37:25.216969 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 32) ::1.52600 > ::1.3350: Flags [.], cksum 0x0028 (incorrect -> 0xdf83), ack 31, win 512, options [nop,nop,TS val 4262616519 ecr 4262616519], length 0
01:37:25.254713 IP6 (flowlabel 0xe10b3, hlim 64, next-header TCP (6) payload length: 32) ::1.3350 > ::1.52600: Flags [F.], cksum 0x0028 (incorrect -> 0xdf5c), seq 31, ack 78, win 512, options [nop,nop,TS val 4262616557 ecr 4262616519], length 0
01:37:25.297973 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 32) ::1.52600 > ::1.3350: Flags [.], cksum 0x0028 (incorrect -> 0xdf0b), ack 32, win 512, options [nop,nop,TS val 4262616600 ecr 4262616557], length 0
01:37:25.886713 IP6 (flowlabel 0xc281a, hlim 64, next-header TCP (6) payload length: 32) ::1.52600 > ::1.3350: Flags [F.], cksum 0x0028 (incorrect -> 0xdcbd), seq 78, ack 32, win 512, options [nop,nop,TS val 4262617189 ecr 4262616557], length 0
01:37:25.886737 IP6 (flowlabel 0xc429c, hlim 64, next-header TCP (6) payload length: 32) ::1.3350 > ::1.52600: Flags [.], cksum 0x0028 (incorrect -> 0xda45), ack 79, win 512, options [nop,nop,TS val 4262617189 ecr 4262617189], length 0
01:37:41.603074 IP6 (flowlabel 0x461f5, hlim 64, next-header TCP (6) payload length: 32) ::1.46136 > ::1.3350: Flags [F.], cksum 0x0028 (incorrect -> 0x23fc), seq 3577026672, ack 1112127163, win 512, options [nop,nop,TS val 4262632906 ecr 4262596309], length 0
01:37:41.603101 IP6 (flowlabel 0xeaed7, hlim 64, next-header TCP (6) payload length: 32) ::1.3350 > ::1.46136: Flags [.], cksum 0x0028 (incorrect -> 0x9506), ack 1, win 512, options [nop,nop,TS val 4262632906 ecr 4262632906], length 0
```
我们也可以利用 journalctl -xf 查看日志
```shell
Aug 18 01:45:02 freeabc xrdp[10507]: (10507)(139797313210176)[INFO ] Socket 12: AF_INET6 connection received from ::ffff:192.168.222.1 port 56030
Aug 18 01:45:02 freeabc xrdp[10507]: (10507)(139797313210176)[DEBUG] Closed socket 12 (AF_INET6 ::ffff:192.168.222.178 port 3389)
Aug 18 01:45:02 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Closed socket 11 (AF_INET6 :: port 3389)
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] Using default X.509 certificate: /etc/xrdp/cert.pem
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] Using default X.509 key file: /etc/xrdp/key.pem
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] TLSv1.2 enabled
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] TLSv1.1 enabled
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] TLSv1 enabled
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Security layer: requested 11, selected 1
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] connected client computer name: DESKTOP-9PAUEP4
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] TLS connection established from ::ffff:192.168.222.1 port 56030: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_000029bf_wm_login_mode_event_00000001
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] Cannot find keymap file /etc/xrdp/km-00000804.ini
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] Cannot find keymap file /etc/xrdp/km-00000804.ini
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] Loading keymap file /etc/xrdp/km-00000409.ini
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[WARN ] local keymap file for 0x00000804 found and doesn't match built in keymap, using local keymap file
Aug 18 01:45:03 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_wm_log_msg: connecting to sesman ip 127.0.0.1 port 3350
Aug 18 01:45:03 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[INFO ] A connection received from ::1 port 36482
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] xrdp_wm_log_msg: sesman connect ok
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_wm_log_msg: sending login info to session manager, please wait...
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] return value from xrdp_mm_connect 0
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[INFO ] ++ created session (access granted): username root, ip ::ffff:192.168.222.1:56030 - socket: 12
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[INFO ] starting Xorg session...
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[DEBUG] Closed socket 9 (AF_INET6 :: port 5911)
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[DEBUG] Closed socket 9 (AF_INET6 :: port 6011)
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[DEBUG] Closed socket 9 (AF_INET6 :: port 6211)
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[INFO ] calling auth_start_session from pid 10688
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] xrdp_wm_log_msg: login successful for display 11
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: pam_unix(xrdp-sesman:session): session opened for user root by (uid=0)
Aug 18 01:45:04 freeabc systemd-logind[1076]: New session c15 of user root.
-- Subject: A new session c15 has been created for user root
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
-- Documentation: https://www.freedesktop.org/wiki/Software/systemd/multiseat
--
-- A new session with the ID c15 has been created for the user root.
--
-- The leading process of the session is 10688.
Aug 18 01:45:04 freeabc systemd[1]: Started Session c15 of user root.
-- Subject: Unit session-c15.scope has finished start-up
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit session-c15.scope has finished starting up.
--
-- The start-up result is RESULT.
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] Closed socket 7 (AF_INET6 ::1 port 3350)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_wm_log_msg: started connecting
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] Closed socket 8 (AF_INET6 ::1 port 3350)
Aug 18 01:45:04 freeabc xrdp-sesman[10690]: (10690)(140145709626688)[INFO ] /usr/lib/xorg/Xorg :11 -auth .Xauthority -config xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[CORE ] waiting for window manager (pid 10689) to exit
Aug 18 01:45:04 freeabc systemd[1487]: Started GnuPG cryptographic agent and passphrase cache.
-- Subject: Unit UNIT has finished start-up
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit UNIT has finished starting up.
--
-- The start-up result is RESULT.
Aug 18 01:45:04 freeabc gpg-agent[10760]: gpg-agent (GnuPG) 2.2.4 starting in supervised mode.
Aug 18 01:45:04 freeabc gpg-agent[10760]: using fd 3 for ssh socket (/run/user/0/gnupg/S.gpg-agent.ssh)
Aug 18 01:45:04 freeabc gpg-agent[10760]: using fd 4 for extra socket (/run/user/0/gnupg/S.gpg-agent.extra)
Aug 18 01:45:04 freeabc gpg-agent[10760]: using fd 5 for std socket (/run/user/0/gnupg/S.gpg-agent)
Aug 18 01:45:04 freeabc gpg-agent[10760]: using fd 6 for browser socket (/run/user/0/gnupg/S.gpg-agent.browser)
Aug 18 01:45:04 freeabc gpg-agent[10760]: listening on: std=5 extra=4 browser=6 ssh=3
Aug 18 01:45:04 freeabc kernel: xfce4-session[10742]: segfault at 2c ip 0000556e4a4fe8c6 sp 00007ffedc54cd30 error 4 in xfce4-session[556e4a4d2000+45000]
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] lib_mod_log_peer: xrdp_pid=10687 connected to X11rdp_pid=10690 X11rdp_uid=0 X11rdp_gid=0 client_ip=::ffff:192.168.222.1 client_port=56030
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_wm_log_msg: connected ok
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_mm_connect_chansrv: chansrv connect successful
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Closed socket 20 (AF_INET6 ::1 port 36482)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] The following channel is allowed: rdpdr (0)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] The following channel is allowed: rdpsnd (1)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] The following channel is allowed: cliprdr (2)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[INFO ] The following channel is allowed: drdynvc (3)
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] The allow channel list now initialized for this session
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[CORE ] window manager (pid 10689) did exit, cleaning up session
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[INFO ] calling auth_stop_session and auth_end from pid 10688
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: pam_unix(xrdp-sesman:session): session closed for user root
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] cleanup_sockets:
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Closed socket 22 (AF_UNIX)
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] cleanup_sockets: deleting /var/run/xrdp/sockdir/xrdp_chansrv_audio_out_socket_11
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Closed socket 12 (AF_INET6 ::ffff:192.168.222.178 port 3389)
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] cleanup_sockets: deleting /var/run/xrdp/sockdir/xrdp_chansrv_audio_in_socket_11
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] xrdp_mm_module_cleanup
Aug 18 01:45:04 freeabc xrdp[10687]: (10687)(139797313210176)[DEBUG] Closed socket 21 (AF_UNIX)
Aug 18 01:45:04 freeabc xrdp-sesman[10688]: (10688)(140145709626688)[DEBUG] cleanup_sockets: deleting /var/run/xrdp/sockdir/xrdpapi_11
Aug 18 01:45:04 freeabc xrdp-sesman[10471]: (10471)(140145709626688)[INFO ] ++ terminated session: username root, display :11.0, session_pid 10688, ip ::ffff:192.168.222.1:56030 - socket: 12
Aug 18 01:45:14 freeabc systemd-logind[1076]: Removed session c15.
-- Subject: Session c15 has been terminated
```
这个日志可以看到更清楚的流程,具体日志见上
我们看到这个没启动起来是 xfce4-session[10742]: segfault at 2c ip 0000556e4a4fe8c6 sp 00007ffedc54cd30 error 4 in xfce4-session[556e4a4d2000+45000] 有段错误
这个错误,我们可以单独运行 xfce4-session 查看原因
```shell
xfwm4-Message: 02:00:03.303: Another Window Manager (Xfwm4) is already running on screen :10.0
xfwm4-Message: 02:00:03.303: To replace the current window manager, try "--replace"
(xfwm4:11384): xfwm4-WARNING **: 02:00:03.303: Could not find a screen to manage, exiting
```
我们看到是另外一个 Xfwn4 已经启动在 screen :10.0 了,可以运行 xfwm4 --replace 替换一下
对用户的授权,我们通过日志可以观察到是通过文件 ~/.Xauthority
5. xrdp-sesman 会根据 sesman.ini 调用 /etc/xrdp/startwm.sh这个脚本最终会调用 /etc/X11/Xsession 这个脚本, Xsession 这个脚本大有文章
```shell
SYSSESSIONDIR=/etc/X11/Xsession.d
USERXSESSION=$HOME/.xsession ---> 看到没有这就是我们经常看到的很多文章推荐的 echo "xfce4-session" > ~/.xsession 的原因,设置 Xsession 的环境变量
...
SESSIONFILES=$(run-parts --list $SYSSESSIONDIR) ---> 最终会执行 /etc/X11/Xsession.d 下的脚本,我们所有的窗口会话实现,应该放到这个里面
if [ -n "$SESSIONFILES" ]; then
set +e
for SESSIONFILE in $SESSIONFILES; do
echo $SESSIONFILES >> /root/my.log
. $SESSIONFILE
done
set -e
fi
```
/etc/X11/Xsession.d/20dbus_xdg-runtime
/etc/X11/Xsession.d/20x11-common_process-args
/etc/X11/Xsession.d/30x11-common_xresources
/etc/X11/Xsession.d/35x11-common_xhost-local
/etc/X11/Xsession.d/40x11-common_xsessionrc
/etc/X11/Xsession.d/50x11-common_determine-startup
/etc/X11/Xsession.d/60x11-common_localhost
/etc/X11/Xsession.d/60x11-common_xdg_path
/etc/X11/Xsession.d/75dbus_dbus-launch
/etc/X11/Xsession.d/90gpg-agent
/etc/X11/Xsession.d/90qt-a11y
/etc/X11/Xsession.d/90x11-common_ssh-agent
/etc/X11/Xsession.d/95dbus_update-activation-env
/etc/X11/Xsession.d/99x11-common_start
参数 STARTUP 赋值
我们看到执行 /etc/X11/Xsession.d/50x11-common_determine-startup 时,会 STARTUP="$shell $STARTUPFILE" 其实就是 /bin/bash /root/.xsession , root就是 ~ 我们用 root 登录的。
参数 STARTUP 运行
我们跟踪执行 /etc/X11/Xsession.d/99x11-common_start/99x11-common_start 时exec $STARTUP 这个其实就是执行 xfce4-session 了,至此 xfce4-session 启动完成
xfce4-session 会读取 下面的文件,并执行里面的命令
https://manpages.ubuntu.com/manpages/xenial/man1/xfce4-session.1.html
xfce4-session reads its configuration from Xfconf. xfce4-session stores its session data into $XDG_CACHE_HOME/sessions/.
具体配置文件就是 /usr/local/etc/xdg/xfce4/xfconf/xfce-perchannel-xml/xfce4-session.xml
```xml
<?xml version="1.0" encoding="UTF-8"?>
<channel name="xfce4-session" version="1.0">
<property name="general" type="empty">
<property name="FailsafeSessionName" type="string" value="Failsafe"/>
<property name="LockCommand" type="string" value=""/>
</property>
<property name="sessions" type="empty">
<property name="Failsafe" type="empty">
<property name="IsFailsafe" type="bool" value="true"/>
<property name="Count" type="int" value="5"/>
<property name="Client0_Command" type="array">
<value type="string" value="xfwm4"/>
</property>
<property name="Client0_Priority" type="int" value="15"/>
<property name="Client0_PerScreen" type="bool" value="false"/>
<property name="Client1_Command" type="array">
<value type="string" value="xfsettingsd"/>
</property>
<property name="Client1_Priority" type="int" value="20"/>
<property name="Client1_PerScreen" type="bool" value="false"/>
<property name="Client2_Command" type="array">
<value type="string" value="xfce4-panel"/>
</property>
<property name="Client2_Priority" type="int" value="25"/>
<property name="Client2_PerScreen" type="bool" value="false"/>
<property name="Client3_Command" type="array">
<value type="string" value="Thunar"/>
<value type="string" value="--daemon"/>
</property>
<property name="Client3_Priority" type="int" value="30"/>
<property name="Client3_PerScreen" type="bool" value="false"/>
<property name="Client4_Command" type="array">
<value type="string" value="xfdesktop"/>
</property>
<property name="Client4_Priority" type="int" value="35"/>
<property name="Client4_PerScreen" type="bool" value="false"/>
</property>
</property>
</channel>
```
我们看到一个会话启动五个最基本的服务 xfwm4, xfsettingsd, xfce4-panel, Thunar, xfdesktop如果启动失败请依次排查这几个服务是否正常
如果只出状态栏和 Dock ,桌面出现黑屏,基本上是 xfdesktop 启动失败,可能依赖的库不满足,缺少什么库,这个需要具体问题具体分析了
# 常见问题解决方法
1. 解决 Fontconfig error: Cannot load default config file: No such file
cp /root/test/a/usr/local/etc/* /usr/local/etc/ -rf
2. 解决 Cannot read private key file /etc/xrdp/key.pem: Permission denied
```shell
adduser xrdp ssl-cert
reboot
```
3. 解决 libpango 库多版本的环境下,系统的低版本优先加载,导致 xfdesktop 不能正常启动的问题我们可以这么做
```shell
libdir=`pwd`"/a/usr"
echo "LD_LIBRARY_PATH=\"${libdir}/lib:${libdir}/local/lib:${libdir}/lib/x86_64-linux-gnu\" xfce4-session" > ~/.xsession
```
这样就可以优先加载我们编译的动态库了
4. xfce4-session 其实相应的配置也可以通过命令行工具查看
xfconf-query -c xfce4-session -p /sessions/Failsafe/Client3_Command
我们可以逐行查看每个属性,然后通过 ps -aef | grep xf* 查看相应的进程是否正确启动,如果没有启动,就会导致出现问题,然后单独手工启动那个进程,查看是什么原因导致不能正常启动的,解决问题就非常简单了。