How to "Exit" full screen in rdesktop

When you hit ctrl+alt+enter in the RDP session, it should exit the full screen mode... But something in Compiz causes a problem.

System > Prefrences > Advanced Desktop Effects Settings Utility > Workarounds > uncheck Legacy Fullscreen Support

That should do it…

The powerful session manager: Screen

After my supervisor bought this fancy new desktop computer for me, while I am still waiting for the release of Ubuntu 9.04, the first thing I did is installing Microsoft Windows on it. Such a shame thing to do...

Well, I have my reasons though. One thing I assumed that I can "only" do on Windows is Remote Desktop Protocol. VNC is as slow as a snail, ssh -X is really fun except for one thing: it is still a ssh session, which means everything stops if the connection is closed, or, when I just want to shut down my own lap-top. So my requirement is really simple. I want something that is really fast (command line OK), and can still running when I close the current session. Thus, I can setup a program at work, go back home, login to see if everything works fine, modify a little bit if necessary, shut down my lap-top and go to sleep, leaving the server to finish my work.

Is that too much to ask for Linux? No! I realized I just missed one really powerful thing, which has been there (obviously) for a LONG time. It is called "screen". It is just a window manager like xterm, but you can detach from it and reattach anytime you want.

Two really helpful How-Tos:
http://www.rackaid.com/resources/linux-tutorials/general-tutorials/using-screen/
http://www.linuxforums.org/applications/the_screen_program.html

To start a session: type "screen".
inside the session, Ctrl-A ? to see a list of short cuts.
Ctrl-A c for a new window, and Ctrl-A n or Ctrl-A p to switch between opened windows. Ctrl-A K will kill the current window (and the running program).
Ctrl-A d to detach, and then you will find yourself back to the shell, with all your program running in a screen session.

Type screen -ls, you will see all the screen sessions running, and by type:
screen -r SESSION_NAME
You will get back to that session.

Thus, I can just ssh to that server, open a screen with a bunch of Matlab, detach, close that ssh, go back home, re-login and see the output during the process. Yea!

Python Looping小技巧

Python下面的循环有很多看起来花哨其实很实用的技巧。首当其冲的就是enumerate()，花哨到用语言很难讲清楚...小例子如下：

for i, v in enumerate(['tic', 'tac', 'toe']):
print i, v

0 tic
1 tac
2 toe

在编程的时候大家经常要用到的情况，就是控制循环的index同时是用来访问某一个数组的。比如用Matlab实现：

arr = {'tic', 'tac', 'toe'};

for i = 1:length(arr)
fprintf('%d %s', i, arr{i});
end

相比之下，大家就知道我为什么说enumerate()实在是很fancy的一个东西。

但enumerate()和我们一直理解的循环有一个很重要的区别，那就是循环的进行不是靠i的值控制的，而是靠enumerate来控制的。咱们写循环的时候一个常见的错误就是循环套循环的时候经常用一样的变量“i”来控制，这样就会出很诡异很诡异的问题，debug都不容易找到。但是在Python下面：

for i, season in enumerate(['Spring', 'Summer', 'Fall', 'Winter']):
print i, season
for i, day in enumerate(['Wed', 'Thu', 'Fri', 'Sat']):
print i, day

0 Spring
0 Wed
1 Thu
2 Fri
3 Sat
1 Summer
0 Wed
1 Thu
2 Fri
3 Sat
2 Fall
0 Wed
1 Thu
2 Fri
3 Sat
3 Winter
0 Wed
1 Thu
2 Fri
3 Sat

虽然我在两层循环用了一样的i，但Python根本不鸟这个，只管用enumerate()生成(index, arr[index])对，生成完之后循环结束。如果我用matlab这样写：

S = {'Spring', 'Summer', 'Fall', 'Winter'};
D = {'Wed', 'Thu', 'Fri', 'Sat'};

for i = 1:length(S)
disp(S{i});
for i = 1:length(D)
disp(D{i});
end
end

大家都知道什么后果了吧...

Enumerate还有一个非常Fancy的例子：

fp = open("file", "r")
for i, line in enumerate(fp):
print "line number: " + lineno + ": " + line.rstrip()

可以一行一行把一个文件读出来，而且很省内存，只要你的内存能装下那一行就行了。在需要把一个超大文本文件里的数据读出来处理的时候，这个例子非常有用。

最后再帖一个enumerate之外控制循环的例子，也是相当fancy的：

questions = ['name', 'quest', 'favorite color']
answers = ['lancelot', 'the holy grail', 'blue']
for q, a in zip(questions, answers):
print 'What is your ' + q + '?', 'It is ' + a + '.'

What is your name? It is lancelot.
What is your quest? It is the holy grail.
What is your favorite color? It is blue.