If you use VMware Player or VMware workstation under Linux and you’re an alt-tab fan like me, you might end up with stuck modifier keys, so you can’t use keys like Ctrl, Alt or Shift outside of VMware. Xiao Feng has written a nice script to recover from this annoying condition without having to reboot, and I tought I’d share it with everyone out there:
#!/bin/sh
# Xiao Feng's "Recovering from stuck modifier keys caused by VMware"
# http://bitubique.com/tutorials/recovering-from-stuck-modifier-keys
/usr/bin/xmodmap - << fixme
clear shift
add shift = Shift_L Shift_R
clear lock
add lock = Caps_Lock
clear control
add control = Control_L Control_R
clear mod1
add mod1 = Alt_L Alt_R
clear mod2
add mod2 = Num_Lock
clear mod3
clear mod4
add mod4 = Super_L Super_R
clear mod5
add mod5 = Scroll_Lock
fixme
xset r on
xset m 3.5 4
xset b off
xset s off
Category: Tech
A brief note about Spamhaus Policy Block List
After getting in closer-than-usual acquaintance with my mail server logs I thought I’d share a brief note I found in the Spamhaus PBL FAQ:
The first thing to know is: THE PBL IS NOT A BLACKLIST.
Oh, and since you’re already there you may want to linger a bit in this warning:
WARNING! Some post-delivery filters use “full Received line traversal” or “deep parsing”, where the filter reads all the IPs in the Received lines. Legitimate users, correctly sending good mail out through their ISP’s smarthost, will have PBL-listed IPs show up in the first (lowest) Received header where their ISP picks it up. Such mail should not be blocked! So, you should tell your filters to stop comparing IPs against PBL at the IP which hands off to your mail server! That last hand-off IP is the one which PBL is designed to check. If you cannot configure your filters that way, then do not use PBL to filter your mail. Instead, you may wish to use sbl-xbl.spamhaus.org, but even that may have unacceptable “false positive” filtering, for example when a an exploited end-user machine sends legitimate mail out through the ISP smarthost, or when the dynamic assignment changes the IP to an uninfected machine. Do not use PBL or XBL if you do not understand the issues of “deep parsing”.
(Emphasis mine)
So if your top-of-the-line multi-thousand-dollar antispam appliance starts blocking all my email just because there’s a dynamic IP address somewhere in the header and there’s no freaking way to turn it off please go ask for a refund. And stop bouncing my messages.
Oh and by the way the default SpamAssassin configuration in Debian assigns a 0.905 score if the last hop is in PBL.
score RCVD_IN_PBL 0 0.509 0 0.905
...
header RCVD_IN_PBL eval:check_rbl('zen-lastexternal', 'zen.spamhaus.org.', '127.0.0.1[01]')
And yes, SpamAssassin does the right thing and checks only the *last* external address — I’ve seen the code:
package Mail::SpamAssassin::PerMsgStatus;
...
# If name is foo-lastexternal, check only the Received header just before
# it enters our internal networks; we can trust it and it's the one that
# passed mail between networks
So once again kudos to Open Source — and Common Sense.
DiskAid: access the files in your iPhone or iPod Touch
A few weeks ago I upgraded my wife’s iPod Touch to 2.1, and I just can’t believe that iTunes won’t let you backup your content even if it means a paid firmware upgrade. I would have used PodsBlitz to back it up, except that Apple decided that it would be a good idea to strip off the disk mode from the iPod Touch.
I decided that there was nothing to be done for the music files: I would have copy the files manually after the upgrade, hoping to replicate my wife’s original selection as closely as possible. But that iPod also has a few of my daugther’s favorite movies… I rightly believed we could have a problem there. I’ve been converting her favorite DVDs for a year, and I carelessly deleted the converted files from the PC a long time ago leaving two options: either invest a few afternoons re-converting those DVDs, or somehow get those files out of the iPod and restore them later.
After a few google searches I stumbled upon a couple of promising projects that some day may grant you unrestricted access to the media residing in your iPod Touch, but those just refused to work in my wife’s PC. A few more queries later I found DigiDNA DiskAid, a nice little utility that speaks the iPod’s obscure file transfer protocol over USB and that lets you copy files back and forth. It’s far from perfect — it wiill only show the physical filename instead of the “real”, tag-based one, and it only does alphabetical sorting, even when sorting by file size. This made hunting for those movie files kind of annoying — annoying but *possible*, which is a lot more that can be said for Apple’s tools.
uHOWTO: Use your N95 8G as a bluetooth modem under Linux with Telcel
For completeness, here’s a followup to my post about using a Nokia N95 as a bluetooth modem under Linux. This is a working wvdial configuration for use with Telcel in Mexico.
Remember to enter your SIM’s PIN in pin-telcel, and refer to my previous post for complete instructions.
[Dialer pin-telcel]
Modem = /dev/rfcomm0
Baud = 460800
Init1 =AT+Cpin=XXXX
[Dialer telcel]
Phone = *99***1#
Username = telcel
Password = telcel
Stupid Mode = 1
Dial Command = ATDT
Check Def Route = on
Dial Attempts = 3
Modem = /dev/rfcomm0
Baud = 460800
Init2 = ATZ
Init3 = ATQ0 V1 E0 S0=0 &C1 &D2 +FCLASS=0
Init4 = AT+CGDCONT=1,"IP","internet.itelcel.com"
ISDN = 0
Modem Type = Analog Modem
To use it, enter
# wvdial vodafone-pin
# wvdial vodafone
Enjoy!
HOWTO: Use your Nokia N95 Cellphone as a Bluetooth modem for Linux
Did you know that you can use your data-enabled N95 to get a thethered Internet connection from Linux? The access mode and speed will depend on your actual coberture, and as usual YMMV, but I’ve been using this setup for a few months and it works fine.
$ sudo -s
# apt-get install bluetooth bluez-pin bluez-utils kdebluetooth wvdial
Now in user mode use KBlueMon to find out the Bluetooth address of your device and write it down.
Then go ahead and initiate an OBEX file transfer to make sure that you can actually link to your phone and to establish a trust relationship. In your phone add the Laptop to your trusted device list, so it won’t nag you whenever you establish a link.
Now edit /etc/bluetooth/rfcomm.conf :
rfcomm0 {
bind yes;
device 00:21:09:XX:XX:XX;
channel 2;
}
Replace your own device address after “device”.
Now edit /etc/wvdial to add these two entries:
[Dialer pin-vodafone]
Modem = /dev/rfcomm0
Baud = 460800
Init1 =AT+Cpin=XXXX
[Dialer vodafone]
Phone = *99***1#
Username = vodafone
Password = vodafone
Stupid Mode = 1
Dial Command = ATDT
Check Def Route = on
Dial Attempts = 3
Modem = /dev/rfcomm0
Baud = 460800
Init2 = ATZ
Init3 = ATQ0 V1 E0 S0=0 &C1 &D2 +FCLASS=0
Init4 = AT+CGDCONT=1,"IP","ac.vodafone.es"
ISDN = 0
Modem Type = Analog Modem
You can give them any name you want. I have defined several providers, to avoid confusions and to use the provider at hand. Replace the “XXXX” in Init1 with your SIM’s PIN.
Now to use them restart the Bluetooth subsystem:
# /etc/init.d/bluetooth restart
And use wvdial to dial out:
# wvdial vodafone-pin
# wvdial vodafone
You should get an Internet link, complete with an IP, a default route and a couple of DNS servers. If it doesn’t, reboot your phone liberally.
Please note that this might get expensive quite quickly unless you get a data plan from your provider. Go ahead and make their day.
Enjoy!
Farewell to Arthur C. Clarke
I just found out -thorugh an email from Thinkgeek, of all ways- that Arthur C. Clarke has passed away.
2001 was a mesmerizing experience for me when I first saw it. I think I was about 8 years old then. A few years later I got to read 2010, 2061, 3001, the Rama series, and many, many of his stories and novels. One of my dearest possessions is a volume of his collected works that I got as a birthday gift from my brother.
I admire Arthur’s foresight and his use of technology to collaborate with people in the other side of the earth, through fax first and through email later. I remember my surprise when I read in a magazine that he was an avid user of PC computer program that allowed him I to explore the surface of Mars from the comfort of his desktop. Moreover, I was frankly amazed when I learned in high school that he was not only a prolific science fiction writer: I found out that he actually devised the use of satellites in geosynchronous orbit to relay radio signals, thus launching the global, instant-communications era that we live in today. As a member of a geographically-distributed family, I can’t be more grateful.
And in regards to his extraordinary vision, bouncing a radio signal off a satellite in high orbit might have seemed like a fantasy for most laypeople back in the 40s, just like the concept of a space elevator -another Clarke invention- might seem outrageously outlandish to the vast majority of people today. But I trust that we might live to see one in our lifetime. While fact checking these sad news, I found a video with Arthur C. Clarke’s reflections on his 90th birthday. I am not ashamed to say that tears come to my eyes listening to his words.
My heart mourns the loss of an extraordinary science fiction writer, but my mind celebrates the life of an extraordinary scientist.
Farewell, Sir!
Prodigy Infinitum, SMTP through port 25, botnets and such
After pulling my hair for a couple of days I just realized that my DSL provider is blocking all outgoing connections to port 25 with an ICMP Unreachable packet, which translates as a totally bogus “no route to host” message (An ICMP RST would be more kosher, BTW). The only explanation that comes to my mind is that Telmex has finally realized that it has become one of the largest botnet hosts in the world and decided to do something about it. This is a terrible inconvenience for me, because I run a backup MX at my home office and all the email I write while I’m at home is relayed through it. And now it believes that it has been cut out from the Internet, and is suffering from Internet withdrawal syndrome. Oh, and all attempts to use an external relay -like my primary MTA or the office’s- through port 25 fail as well, so I have had to set up an elaborate workaround *just to send email*.
*Argh!* I hate to pay up for those ignorant Windows home users.
Add to that the fact that i get 800KBps tops in a 2GBps line, and recurrent reports of arbitrary bandwidth capping and Infinitum stops looking like a good alternative for home broadband. I’ll have to look for a cost-effective alternative, but after experiencing 20MBps/20EUR in Europe I’m afraid that I’ve been spoiled for life.
In the meantime, if you were expecting a mail from me in the last five days or so, I’m sorry to say that it is either on its way or lost forever.
Anyway… Merry Christmas!
Update 20080104: AJ Gibson points out in a comment that Telmex is willing to remove the block from your account if you are willing to jump through a few hoops. Just go to http://www.telmex.com/mx/asistencia/correoelectronico/faq_puerto_25.html and follow the instructions there. I registered yesterday and today I can connect back to external SMTP servers again. As mentioned in the comments, YMMV.
Bourne Shell Server Pages
Easy. Portable. Buzzword-compliant. Ingenuous. Elegant. Right-out wicked cool: Bourne Shell Server Pages. As I write this I’m looking for a excuse to use this revolutionary technology in my next project!
Behold the simplicity of ASP and the power of sh:
<html>
<body>
<h1><$ echo "Hello, world!" $></h1>
</body>
</html>
Interface21: please take note. I expect a Spring.sh implementation before the year ends. ;-)
[tags]bourneShell, asp, jsp[/tags]
About typos in technical manuals
The product you are in charge of maintaining has been in active use for a decade. The manual is several megabytes long, and there’s an army of programmers, consultants and technical writers that make a living off it. As you might guess, it’s not an inexpensive product.
One of the routine tasks for that product -let’s say, “create a new UCM project”- is throughtly documented for the GUI use case, but the manual makes absolutely no mention of the CLI-based procedure. You go through the whole procedure armed with the aforementioned documentation and lots and lots of patience, second-guessing the developers and the technical writers every step of the way, but getting the work done with varying amounts of effort and frustration.
Then, in a key command, you hit a wall. The program complains:
Created project "gpa3_project". cleartool: Error: Unknown policy name "POLICY_DELIVER_NCO_SELACTS" specified. cleartool: Error: Cannot set all the policy pvars on project "gpa3_project". Project "gpa3_project" is now ClearQuest-enabled and linked to ClearQuest database "COFCQ".
Now “POLICY_DELIVER_NCO_SELACTS” returns *exactly* one match in Google, and it points to the aforementioned documentation. It’s “POLICY_DELIVER_NCO_SELACTS” all over.
After a lot of frustration,
strings /opt/rational/clearcase/linux_x86/shlib/libatriasum.so|grep -i policy_|sort
shows that “POLICY_DELIVER_NCO_SELACTS” is a typo. They really meant “POLICY_DELIVER_NCO_SELACT” instead. No final “S”, you see! And this happened SOME TIME IN THE LAST TEN FREAKING YEARS.
The list of things I’d like to do to the project managers, documentors, and technical writers of this particular product suite is too graphic even for the Internet.
And most importantly — how do they get away with these levels of incompetence?
Whitespace Matters
Mark Jason Dominus just released SuperPython 0.91, “a Perl source filter for the SuperPython language, allowing SuperPython code to be embedded into Perl programs”.
In terms of language, it goes way beyond python itself to give proper semantics to whitespace. For instance, here is the Hello World program written in SuperPython:
#!/usr/bin/perl
use SuperPython;
Ain’t it neat? Naturally, the result is
$ ./hello.spy Hello, world.
just as would be expected.
If you want to try this program yourself you might be surprised to find out that copy+paste won’t work, but that’s a small price to pay in exchange or the benefits of the richness of syntax and expresiveness of the language, and anyway you may download the source code for hello.spy right here.
Mark is very optimist in contributing the new features of SuperPython back to python itself, and has kindly offered to work closely with the Python community to see this happen.
Congrats Mark, and keep up the good work!
[tags]code, perl, python, computer languages[/tags]