使用rdesktop远程连接Windows桌面

之前使用的是KDE下的krdc。该程序的Grab Keys功能存在bug，导致Alt+TAB大多数时候不能被捕捉，从而无法使用键盘切换窗口。不过，其全屏功能是正常的，在多显示器的情况下，全屏只在一个屏幕上有效。最终，还是换回到rdesktop。命令如下：

rdesktop -a 32 -u user_name  -g 1920x1030 -x 0x80 -r clipboard:PRIMARYCLIPBOARD 192.168.1.102

其中，各选项含意如下：

-a 32：使用32位color；
-u创：指定用户名；
-g 1920x1030：指定窗口大小。由于在多显示器情况下，rdesktop在全屏的时候会扩展到两个屏幕上，因此，不能使用-f全屏选项，而只能直接指定窗口大小。原本Home PC主显示器的分辨率为1920x1080，将高度设置为1030是由于底部工具栏的高度。然后，在KDE Special windows settings中将rdesktop的标题栏隐藏，则可以最终实现类似于全屏的效果；
-x 0x80：指定user experience level。在rdesktop的源码中有：#define RDP5_ENABLE_FONT_SMOOTHING 0x80。因此，将该值设为0x80，则可以显示出最好的字体效果。（原先设置的为lan，虽然使颜色深度加到了最大值32，但是字体显示没有ClearType效果）；
-r clipboard:PRIMARYCLIPBOARD：实现本机与远程主机间的剪贴板共享；
最后指定远程主机的IP地址。

创建了如下的脚本rdcwin，用于连接远程主机：

#!/bin/bash

if [ -z $1 ]; then
    echo "Default host 192.168.1.102 will be conneted!"
    host=192.168.1.102
else
    host=$1
fi

rdesktop -a 32 -u user_name -g 1920x1030 -x 0x80 -r clipboard:PRIMARYCLIPBOARD $host

更多细节可参考这里:

rdesktop: Connect to Windows 7 and Vista with ClearType font smoothing enabled

So Windows Vista finally allows to enable ClearType font smoothing for Remote Desktop / Terminal Services sessions. Update: Windows XP SP3 does too!

If you try to connect to a machine running Windows XP SP 3 or later using rdesktop, you won’t get smoothed font typing since at the time of this writing rdesktop does not officially offer an option to control this feature. However, here is a workaround:

rdesktop allows to specify the RDP5 experience via the -x experience switch.

One can either define one of three default experiences (modem, broadband, lan) or one can specify a raw hex value that is send to the server.

NOTE: You can skip over this rather technical part, if you’re not interested in the details. You’ll find the workaround below.

This hex value is actually a combination of defined bit flags. After some tinkering I found that the hex value 0×80 will enable font smoothing for the connection.

The file constants.h of the rdesktop sources contains these flags:

#define RDP5_DISABLE_NOTHING 0x00

#define RDP5_NO_WALLPAPER 0x01

#define RDP5_NO_FULLWINDOWDRAG 0x02

#define RDP5_NO_MENUANIMATIONS 0x04

#define RDP5_NO_THEMING 0x08

#define RDP5_NO_CURSOR_SHADOW 0x20

#define RDP5_NO_CURSORSETTINGS 0x40 /* disables cursor blinking */

So, naturally an additional flag constant can be defined like this:

#define RDP5_ENABLE_FONT_SMOOTHING 0x80

The file rdesktop.c would have to be extended preferably with an additional argument that controls the font smoothing.

If you want to use font smoothing with rdesktop now you have to combine the flags (bitwise OR, addition will do too) and specify the result via the -x switch.

Here is the workaround for the three defaults mentioned above:

rdesktop -x 0x8F mywinserver # equals the modem default + font smoothing

rdesktop -x 0x81 mywinserver # equals the broadband default + font smoothing

rdesktop -x 0x80 mywinserver # equals the LAN default + font smoothing