Saturday, January 30, 2010

tcsh Update

Maybe I don't need to worry about changing shells too soon, if only because tcsh is the default shell for UMBC's Linux cluster, GL.

UMBC shell menu


So it's not just me and the OSU of yesteryear, but also UMBC.

Friday, January 29, 2010

LinkedIn Not Worth it Anymore

LinkedIn has been of some value to me in terms of getting back in touch with former coworkers. But they've changed their authentication so that, instead of a login session lasting for the life of a browser process, it times out every day. So now I have to log in every single time I want to visit their site. It's ok with me that Amazon wants my password every time I place an order, but LinkedIn doesn't have my credit card numbers and so forth.

Am I going to delete my LinkedIn account? Not in the immediate future.

Am I going to bother to look at LinkedIn based on the "LinkedIn Network Updates" they send out every week or so? No--it's no longer worth my time.

Am I going to keep my profile up-to-date? Probably not.

Will I periodically visit LinkedIn when I think of a former colleague and wonder where he or she is? No, it's not worth the time.

Saturday, January 23, 2010

tcsh

In my last post I mentioned that I use tcsh. This was a very popular shell on the Ohio State Computer Science Department's Sun 4 and SLC network ca. 1990. It's a supported package under Ubuntu, so it's clearly not dead, at least not entirely. How widely used is it these days? Here's the result from Google Trends:


Google Trends Showing the Decline of tcsh


Clearly the trend is downward. It was about five times as popular as a search term in early 2004 as now. The US ranks eighth in search frequency, and English fifth among languages. I suspect there will come a day when I need to try out a new shell.

sftp "Received message too long 1114795883"

A new semester starts in a few days and it's time to move stuff to the server, but, alas, I couldn't log in to the server. More specifically, ssh worked fine, but sftp failed. And it didn't just fail from my Ubuntu desktop, but from my XP netbook. Clearly it was a problem on the server, but I decided to do a little googling before opening a ticket and suggesting to the IT staff that something was screwed up. Besides, if sftp was broken on a university-wide basis, they probably already knew about it.

Google led here, which had a link to a post from a guy whose last name meshes well with my profile picture.

The problem could be that my .cshrc on the server was generating output that sftp didn't know to deal with. Another blogger somewhere gave a hint regarding what this was, and indeed the decimal 1114795883 in the error message was 0x42726f6b, or, in ASCII: "Brok'. Yes, something was broken, and 4 bytes was all that fit into the integer error message.

So I had to figure out why GL (the server, gl.umbc.edu) was generating extra characters. My default shell is tcsh, so the problem was most likely in the init file, .cshrc. I decided not to look at the system-wide .cshrc initially. I tossed some detritus from my .cshrc, and again failed to log in.

There was still a suspicious line, '/usr/bin/mesg n', at the beginning of the file. Why wasn't this inside the conditional that distinguished between interactive shells and others? I moved it into the conditional, and suddenly I was able to log in.

I had to chuckle. I added that line last semester when a student decided that if we were logged in on GL at the same time, he could chat with me. No. But I was clearly careless when I disabled write.

Sunday, January 17, 2010

CyberMaryland Report

This is a Maryland state government report on cyber security, and worth a glance. There's a summary at http://tynt.com/3eQx, which also has a link to download the report as a PDF. Alternatively, one can use the execrable flash-based browsing interface at issu.com.

Tuesday, January 12, 2010

Rebooting Ubuntu

I miss the old, original behavior of ctrl-alt-del, rebooting the system. Once upon a time, kiddies, computers had front panels. Among the buttons on the front panel was a reset button. With the IBM PC and others of its early '80s ilk, the front panel was gone, and often there was no reset button, but there was the three finger salute.

At some point, Windows behavior was to invoke the task manager on a three finger salute rather than to do a system reset. Slackware and other early Linux distros did a reset, which effectively rebooted the system.

Why do I suddenly care? I'm running Ubuntu 9.10 on a 64-bit HP Pavilion desktop. Multiple times per week the system locks up, and ctrl-alt-del does nothing. The GNOME default is log out, but GNOME is locked up at this point. There's a configuration file, /etc/event.d/control-alt-delete, but so far as I can tell the contents of this file are irrelevant and have no effect on system behavior. So my recourse has been to hold the power button down long enough for an abrupt power down. I've been doing this, on average, multiple times per week, when really all I want to do is reboot.

I want my reset button.

Now it turns out that alt-sysreq-b does a reset. Now I just have to remember to try this the next time my system locks up.

Ubuntu: less impressive with every "upgrade."
Hewlett-Packard: less impressive on a year-by-year basis since the merger with Compaq. I guess I could start telling people I'm old enough to remember when HP sold quality products. I worked for a competitor in the telecom instruments segment, and HP was always considered a very worthy competitor. Their laser printers used to be good. Now it's all cheap junk.