A quickie.

As part of being a bit crazy I flew over to Las Vegas for TAM6: The Amaz!ng Meeting 6. As far as I can tell, there are no other Polish people here; everybody is either American or Canadian. I’ve met only two people from the UK and I’ve heard there’s somebody from Ireland, but I haven’t managed to find them yet.

TAM6 opens today. I’m blogging about it on my Polish blog. If you’re curious, you can try using Google Translate which has now Polish language support, although I might use weird language structures and obscure words (hey, that’s part of writing fun!). Your mileage may vary.

My current hosting provider, hosting365, is a traditional-style hosting service, where file upload is still done via FTP with passwords sent as clear text. They provide ssh access on demand, and it has to be manually approved by company’s staff. I don’t understand why don’t they provide shell by default. Maybe it’s part of being a traditional style hosting and trying to avoid the word “shell” or anything like it.

Shell they provide, but what about public key authentication? No, they don’t. As this is turned on by default in all Linux installations, they must have switched this option off. Why did they do that, remains a mystery as public key authentication is no less secure than password entry.

Let’s suppose I want to automate file upload. When using public key authentication, it’s enough to write something like:

scp foo.jpg mylogin@somehost.com:some/directory/images

This doesn’t work with hosting365. Since their server configuration enforces interactive authentication, scp asks for your password. In this session you can see how scp tries two keys (DSA and RSA) and reverts to keyboard interaction:

debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/maciej/.ssh/id_dsa
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Offering public key: /home/maciej/.ssh/id_rsa
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Trying private key: /home/maciej/.ssh/identity
debug1: Next authentication method: password
automatthias@web1.hosting365.ie's password:

scp doesn’t have a command-line option for password entry. This is reasonable, as ssh, scp’s core technology, has a non-interactive mechanism in place: public key authentication. If you can’t do public key authentication, it is right to ask you for the password.

I could solve that by using FTP (file transfer protocol) instead and send my passwords in clear text over the big bad Internet. I guess that most people would do that, and this is why I believe disabling public key authentication by hosting provider is a bad thing: it encourages people to risk exposure of their passwords on FTP.

It is however possible to automate the keyboard-interactive password entry, using Python and pexpect module. This script will do the job:

#!/usr/bin/python
import pexpect
import sys
fn = sys.argv[1]
dest = sys.argv[2]
# The password is kept in a separate file, with permissions 0600.
password = open("/some/directory/hosting365-password.txt").read().strip()
print "scp'ing %s to %s" % (fn, dest)
child = pexpect.spawn("scp %s %s" % (fn, dest))
child.expect("password:")
print "sending password"
child.sendline(password)
# Setting timeout to 15 minutes. If your upload needs more time,
# increase this value.
child.expect(pexpect.EOF, timeout = 15 * 60)
print "done."

Here, password is stores in cleartext on your hard disk. It’s important to make this file non-world-readable, and it’s also a good idea to place it on an encrypted filesystem (with, say, dm-crypt) or an encrypted directory (encfs).

Continuing my series of short tech notes for future generations.

The problem: ctrl key not working in VNC session. xev command doesn’t show any events coming after pressing ctrl key.

Cause: You’re using Gnome, aren’t you? Gnome has a feature that allows to locate the pointer: if you press and release ctrl key, it will show a small animation around your pointer. Unfortunately, it interferes with vncviewer.

Solution: Few websites, including BBC, offer a fix: System → Preferences → Mouse → Cursors tab…

Problem with the solution: Oh noes! Cursor tab is not there! I can’t change the setting!

Solution to the problem with the solution: Use gconf-editor to change the setting: Applications → System Tools → Configuration Editor. Press CTRL+F. Type: “pointer”. Tick “search also in key names” and press “Find”. Click /desktop/gnome/peripherals/mouse/locate_pointer. Untick the checkbox next to it, on the top right pane.

Randi shares some stories regarding his friend Arthur C. Clarke and makes a comparison of Stanley Kubrick to Steve Jobs.

Here’s an ebuild for Python mocker. Really cool mock module, which doesn’t come up high on Google.

I had this idea for some time now, but I never bothered to draw it. However… here’s my strip, titled “Correct Answers”:

…I did my strip in 10 minutes with bitstrips.com.

I don’t study any more since December 2006. I’ve completed my Masters, and… the game seemed to be over. But when a friend has recommended TTC courses to me, I started listening to them… and become addicted. I’ve completed Philosophy of Religion by James Hall, Great Ideas of Psychology by Daniel N. Robinson and Explaining Social Deviance by Paul Root Wolpe. I’m currently listening to Argumentation: The Study of Effective Reasoning by David Zarefsky. I have a few more courses to go through, so I won’t be out of lectures anytime soon.

However, it turned out that watching them as videos doesn’t work well for me. When I’m at home, I have plenty of other things I’d like to do. But they work well in audio, as I can listen to them when commuting. I’m going to buy new courses in audio, but what about those ones I have already in DVD? Can I convert them into audio?

I’ve put together a shell script, which dumps all tracks from DVD and encodes them into mp3 format. It also normalizes volume, so the voice of the speaker has more or less constant volume, which is good when listening in noisy environment.

It was written on Linux, if you’re a Windows user, you can try running it under Cygwin.

• see it
• download it

It’s a state of mind.

Scammers are learning and adapting. Are we having a Christianity surge in the United States? Yes? Why not take advantage of that? Instead of people dead in a place crash, we now have a dying Christian convert. Here’s an example of new, religious context for the old 419 story.

DEAR BELOVED IN CHRIST,

CALVARY GREETINGS IN THE NAME OF OUR LORD JESUS CHRIST. I AM MRS. EVANGELIST REACHEL MIKE, A WIDOW TO LATE JOSEPH MIKE. I AM 56 YEARS OLD, I AM NOW A NEW CHRISTAIN CONVERT, SUFFERING FROM LONG TIME CANCER OF THE BREAST, FROM ALL INDICATION MY CONDITIONS IS REALLY DETERIORATING AND IT IS QUITE OBVIOUS THAT I WONT LIVE MORE THAN 3 MONTHS, ACCORDING TO MY DOCTORS, THIS IS BECAUSE THE CANCER STAGE HAS GOTTEN TO A VERY BAD STAGE. MY LATE HUSBAND KILLED DURING THE U.S.A RAID AGAINST TERRORISM IN AFGHANISTAN, AND DURING THE PERIOD OF OUR MARRIAGE WE COULDN’T PRODUCE ANY CHILD. MY LATE HUSBAND WAS VERY WEALTHY AND AFTER HIS DEATH, I INHERITED ALL HIS BUSINESS AND WEALTH THE DOCTORS HAS ADVISED ME THAT I MAY NOT LIVE FOR MORE THAN 3 MONTHS, SO I NOW DECIDED TO DIVIDE THE PART OF THIS WEALTH, TO CONTRIBUTE TO THE DEVELOPMENT OF THE CHURCH IN AFRICA, AMERICA, ASIA, AND EUROPE.

I AM WILLING TO DONATE THE SUM OF ($8.5, 000.000.00 M U.S.DOLLARS), TO THE LESS PRIVILEGED. SO I WILL LIKE YOU TO GET THIS FUND AND USE IT TO HELP THE POOR AND THE LESS PRIVILEGED ALL OVER THE WORLD.

I HONESTLY PRAY THAT THIS MONEY WHEN TRANSFERRED WILL BE SURE FOR THE SAID PURPOSE, BECAUSE I HAVE COME TO FIND OUT THAT WEALTH ACQUISITION WITHOUT CHRIST IS VANITY. MAY THE GRACE OF OUR LORD JESUS THE LOVE OF GOD AND THE FELLOWSHIP OF GOD BE WITH YOU AND YOUR FAMILY I AWAIT YOUR URGENT REPLY SOON ON MY PRIVET EMAIL ADD, (evangelistr…@yahoo.it).

YOURS IN CHRIST.

EVANGELIST REACHEL MIKE.

Thank God I’m an atheist.

I was struck by one sentence in the git-svn course.  It’s about the way a computer program displays its output. It’s about colors. Some people like to see code annotated with color, like this:

You can see, that keywords from the programming language are highlighted. Colors are a new channel of information transfer, highlighting code syntax allows us to use our natural ability of color recognition, to work with the code more efficiently.

Without colors, this code looks like this:

Sure, you can still read the code. But… is the word “class” is spelled correctly? Are all the quotes balanced?  You don’t know, unless you examine it quite carefully.  With syntax highlighting, you can determine that by looking: is it yellow or not?

However…

some people hate colors way more than the rest likes them

…and that’s the reason why color highlighting is turned off in git by default. I once heard a convincing argument against colors: that command “ls” with option “–color” calls function stat() on every file it lists, which under certain circumstances is a highly undesired thing; but this argument was then followed by “real UNIX doesn’t have colors” (is it a form of a “real programmer” thing?), which destroyed the whole impression. Yes, sometimes you might want to turn colors off…

But why turn the option off by default for the whole project? The majority has to give in because of loud minority?

In a democratic system, and I believe Free Software movement is about democracy, software should be optimized for the largest benefit of the whole, or at least the majority.

If I find myself among the minority and I can’t get the majority willfully convinced to my option (without hate speeches), I’m going to give in. And I expect the same from others.