Best of Technical Support

Red Hat without a Network Card?

Is it possible to run my Red Hat 8.0 system without a network card?

—
Prasanna


softpras@rediffmail.com

Sure, it's possible, and you don't have to do anything. Any normal Linux system configures lo (the loopback interface) automatically. It's even possible to run without that (as embedded Linux systems sometimes do). However, you shouldn't have to do anything special. Simply install your distribution and refrain from entering any network settings.

—
Jim Dennis


jimd@starshine.org

Incompatible Web Site?

I recently used Konqueror 2.2.2 to visit a credit-card Web site (URL withheld to protect the guilty) to check my account. The site said I needed to upgrade to at least Netscape 4.0 or Microsoft Internet Explorer 4.0 in order to use the 128-bit-strong encryption their site used. I know that Konqueror 2.2.2 is a much later version than 4.0 of either of the browsers they mentioned. I checked the various browser settings, and sure enough, SSL2 and 3 both were enabled, with encryptions going as high as 168 bits. Almost every encryption standard was enabled in my settings; the exceptions being FZA-FZA-CBC-SHA, FZA-NULL-SHA, NULL-MD5 and NULL-SHA—they all say “0 of 0 bits”. Finally, I changed the user agent setting to broadcast that it was Netscape or MSIE, and magically, I stopped getting the error messages. Now when I fill in the forms, such as the login screen, my input is ignored and the form simply refreshes. I have enabled JavaScript, Java and cookies. Nothing works. Am I doing something wrong or is the site nonstandard? If I look in my settings under certificates, it says I have a certificate from the Web site. I can verify that certificate, but it does not say what type of encryption they use or give me any other useful information.

—
John Handis


mrintensity@worldnet.att.net

I'll bet the Web site uses the user agent string to help identify what it thinks is a valid browser version. Try Mozilla. If that doesn't work complain to the Web site.

—
Christopher Wingert


cwingert@qualcomm.com

Too many Web developers code to a particular implementation (target platform) rather than to the standard protocols and APIs (application programming interfaces). This is exacerbated considerably by JavaScript. Writing any piece of nontrivial JavaScript so it can run correctly on several different Web browsers is daunting. I encourage all Web site developers to start with the simplest implementation of the core requirements. Add bells and whistles in JavaScript, but always allow the user to get at core functions without it. My suggestions: complain to your bank and try using Mozilla 1.x or Netscape 6.

—
Jim Dennis


jimd@starshine.org

There is a silver lining, however. You may not be aware of this, but the default Apple browser, Safari, is based on the KHTML rendering engine from the KDE Project. This, obviously, is the same engine that Konqueror uses. Also, now that Microsoft discontinued development on the Macintosh version of Internet Explorer, Web developers who code for Windows and Mac only will be coding for you too.

—
Ben Ford


ben@kalifornia.com

It's Hot in Here

I am using an ASUS motherboard. Under Microsoft Windows 98, a program called asusprobe reports that the CPU temperature is about 47°C/116°F and the motherboard temperature is about 31°C/87°F. These may change slightly but are pretty steady. How do I find these temperatures under Linux?

—
Michael Mather


mmather@eol.ca

Most commodity motherboards that provide this information are built around the LM78 series of chips that communicate over the i2c 2-wire bus. The SMBus is a particular implementation of i2c. The drivers and utilities for accessing this information under Linux are in the lm-sensors package. You can learn more about that project from secure.netroedge.com/~lm78. The i2c and lm-sensors drivers are included with mainstream kernel sources and are compiled into all mainstream Linux distributions like Red Hat, Debian and SuSE. Perusing the FAQ reveals that different motherboards report differing numbers for temperature and voltage; you can adjust those settings by editing the /etc/sensors.conf file. Debian installed a sample sensors.conf file that's about 20 pages long. Also, the FAQ specifically mentions ASUS P2B motherboards in relation to odd temperature readings—if that's your motherboard, read the FAQ at the above URL. Incidentally, a number of packages use this lm-sensors interface, dæmons that store histories of readings for statistical analysis and graphing, GUI widgets that run in KDE, GNOME or Window Maker panels and so on. At the very least you probably should use the sensors command that will read the settings from your /etc/sensors.conf to adjust the raw readings it gets from the drivers.

—
Jim Dennis


jimd@starshine.org

Quick Download of Many Images

Suppose there's a site called www.foo.org/technical/pics. How can I download only the pictures—let's say the only extension is .jpg—from a Web site using wget?

—
Kunthar


kunthar@gmx.net

Here's an example:

wget -r -l1 --no-parent -A "*.jpg" \
http://www.server.com/dir/

This recursively (-r) downloads all the *.jpg files from the dir directory on the www.server.com Web server up to one level depth. Do a man wget for more of this great utility's options.

—
Felipe Barousse Boué


fbarousse@piensa.com