Introducing iPhone 3G. With fast 3G wireless technology, GPS mapping, support for enterprise features like Microsoft Exchange, and the new App Store, iPhone 3G puts even more features at your fingertips. And like the original iPhone, it combines three products in one — a revolutionary phone, a widescreen iPod, and a breakthrough Internet device with rich HTML email and a desktop-class web browser. iPhone 3G. It redefines what a mobile phone can do — again.
Explore2fs is a GUI explorer tool for accessing ext2 and ext3 filesystems. It runs under all versions of Windows and can read almost any ext2 and ext3 filesystem.
A beta version of Virtual Volumes is now available. This is a technology preview for Explore2fs 2. Virtual Volumes also has the ability to read ReiserFS and many other filesystems.
| Program | Version | Content | Format | Platform | Download |
|---|
Windows 95, 98 & ME users should use explore2fs-1.06.zip. Everyone else should use explore2fs-1.08beta9.zip.
Supported versions of Windows:
Features:
Anyone who’s been following Linux kernel development for the past several months has heard about one exciting feature after another being merged into the still un-released 2.6 kernel. New features that noticeably affect user experience include Robert Love’s [interview] preemptible kernel work [story], Ingo Molnar’s [interview] O(1) Scheduler [story], Rik Van Riel’s [interview] reverse mapping VM [story], Nick Piggins’ [interview] Anticipatory I/O scheduler [story], and much, much more…
Having some spare time a few nights ago, I decided to give the latest kernel, 2.6.0-test4, a trial run on my aging 550Mhz PIII desktop computer, and the result was nothing short of spectacular. As the final 2.6.0 release approaches, it is important that an increasing number of users (aka testers) give this kernel a try, especially as currently it’s still a sexy task for developers to track down kernel bugs and stabalize their work. Once work starts on the 2.7 development tree, inevitably much talent will again be focusing on new features.
The purpose of this document is to provide some helpful tips to readers that currently compile their own 2.4 kernels, but haven’t yet made the leap to 2.6. This is still a development kernel, so you may run into problems, but overall stability and performance is quite impressive and I can’t recommend enough that you try it today.
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Beyond that, it’s also highly recommended that anyone new to the 2.6 kernel review Dave Jones’ post-halloween document (aka “2.5 - what to expect”).
Step 0: Make a backup of important data.
Before we get started, if you’re going to be running a development kernel be sure that you have a current backup of any important data. While I’ve not run into any problems while running 2.6.0-test4, there are still bugs…
Step 1: Obtain the current 2.6 kernel.
All official versions of the Linux kernel source code can be found at http://kernel.org/. It is highly encouraged that you find the fastest local mirror to spread out the load among willing kernel source hosts. Find the kernel.org mirror list here: http://kernel.org/mirrors/.
At the time of this writing, the current version of the 2.6 kernel is 2.6.0-test4, a development version. The next release will be -test5, then -test6, and so on, until Linux creator Linus Torvalds decides that it’s time to release 2.6.0, the first official release of the much-anticipated stable 2.6 tree.
Having downloaded the source, it’s also a very good idea to download the GnuPG signature and use it to verify the authenticity and validity of your new kernel source. For more information, go to: http://www.kernel.org/signature.html.
Step 2: Review the provided documentation.
At absolute minimum, you should at least review the top-level README, and the Changes file inside the Documentation directory, both distributed with the Linux kernel source code.
The top-level README refers to itself as being for the 2.5 development kernel, as 2.6.0-test is still part of the development phase. (2.6.0, without a -test extension, will be the first 2.6 kernel) You’ll find lots of good tips in this document regarding how to successfully compile a Linux kernel. The document begins:
“These are the release notes for Linux version 2.5. Read them carefully, as they tell you what this is all about, explain how to install the kernel, and what to do if something goes wrong.”
The Documentation/Changes file lists the new requirements of the 2.5 development kernel, providing a list of software that must be upgraded to work properly with the new kernel. It begins:
“This document is designed to provide a list of the minimum levels of software necessary to run the 2.5 kernels, as well as provide brief instructions regarding any other ‘Gotchas’ users may encounter when trying life on the Bleeding Edge.”
Step 3: Upgrade your system per the Changes file.
There are a number of utilities that you will have to upgrade for them to work properly with your new 2.6 kernel. Some of the utilities listed in ‘Changes’ you won’t have to worry about, as for example they may be specific to certain filesystems. However, you will at least need to meet the minimum version requirements for the following (see ‘Documentation/Changes’ for the latest requirements — they may have changed!):
Name: Minimum version: How to find version:
Gnu C Compiler 2.95.3 gcc --version
Gnu Make 3.78 make --version
binutils 2.12 ld -v
util-linux 2.10o fdformat --version
module-init-tools 0.9.9 depmod -V
procps
2.0.9 ps –version [procps 2.x] [procps 3.x]The following utilities are filesystem specific. If you’re running ext2 or ext3, be sure to update your e2fsprogs, if you’re running jfs, be sure to update jfsutils, etc…
Name: Minimum version: How to find version:
e2fsprogs 1.29 tune2fs
jfsutils 1.0.14 fsck.jfs -V
reiserfsprogs 3.6.3 reiserfsck -V 2>&1 | grep reiserfsprogs
xfsprogs 2.1.0 xfs_db -V
nfs-utils 1.0.5 showmount --version
And a handful of other utilities that you’ll want to update if you use them:
Name: Minimum version: How to find version:
pcmcia-cs 3.1.21 cardmgr -V
quota-tools 3.09 quota -V
PPP 2.4.0 ppd --version
isdn4k-utils 3.1pre1 isdnctrl 2>&1 | grep version
oprofile 0.5.3 oprofiled --version
If you’re going to be running ALSA for the first time, also be sure to visit http://www.alsa-project.org/ to grab the latest alsa-lib and alsa-utils.
Step 4: Configure your new kernel.
One of the first changes you’ll notice is the new build system [story]. The old Tk/Tcl ‘xconfig’ build method no longer exists, replaced by a new QT based ‘xconfig’. Non-QT fans will be happy to find that a GTK based ‘gconfig’ is also available for their use.
2.6 build methods include:
This appears to be identical to ‘config’ in the 2.4 kernel. As the most simplistic configuration method, it simply asks you about each configuration option, one at a time… Requires the ‘bash‘ shell.
This appears to be identical to ‘menuconfig’ in the 2.4 kernel. A simple curses based configuration method.
This new default graphical configuration system uses the QT libraries. I found it to be quite functional and easy to use.
This option is a clone of the new xconfig, however using the GTK libraries instead of the QT libraries. Unfortunately, in my brief testing I found it to be somewhat buggy. While running, it spews out the same error over and over, and crashed rather quickly. Here’s a log to show you what I’m talking about.When configuring your 2.6 kernel for the first time, keep in mind the following tips from the top-level README file that came with your Linux source:
ALSA:
For many people upgrading from 2.4 to 2.6, this will be your first time using the Advanced Linux Sound Architecture (ALSA) which has replaced OSS. Though it may be tempting to simply enable the deprecated OSS and go about your life as normal, it’s probably worth your time to get ALSA working. Thanks to ALSA’s OSS API Emulation, it’s really not that hard. When configuring your kernel, be sure to enable the OSS emulation options (SND_OSSEMUL, SND_MIXER_OSS and SND_PCM_OSS) Also be sure to enable the appropriate sound driver (in PCI devices) - I compiled mine directly into the kernel. Finally, be sure to download and install the latest alsa-lib and alsa-utils.
Step 5: Build your new kernel.
Actually building the kernel is one step easier than in 2.4, as you no longer have to type ‘make dep’. To build a new kernel, type ‘make bzImage’. If you’ve chosen to compile any modules, you’ll also need to ‘make modules’ and ‘make modules_install’. Or, you can string it all together like ‘make bzImage && make modules && make modules_install’.
When the build starts, you’ll notice that the default build process is much quieter than it was in 2.4, providing simple summaries as opposed to all the compiler output.
Step 6: Install your new kernel.
Now that you’ve built your kernel, you need to copy it into place. For example, on x86 you’ll find it in ‘arch/i386/boot’. You’ll want to copy this file and your new System.map into /boot. For example:
# pwd
/usr/src/linux-2.6.0-test4
# mv arch/i386/boot/bzImage /boot/bzImage-2.6.0-test4
# mv System.map /boot/System.map-2.6.0-test4
# cd /boot
# rm System.map
# ln -s System.map-2.6.0-test4 System.map
I noticed that my new 2.6 kernel is bigger than the last 2.4 kernel I compiled with the same version of gcc, however it’s possible that I have more options enabled:
-rw-r--r-- 1 root root 1094390 Aug 12 20:30 bzImage-2.4.21-ck3 -rw-r--r-- 1 root root 1639129 Aug 27 22:06 bzImage-2.6.0-test4
Having copied your new kernel into place, now you need to configure your boot loader. You’re probably using grub [manual] or lilo [howto], refer to the appropriate documentation if you’re unsure how your boot loader works.
Step 7: It’s still not too late…
I’m not trying to scare you, but up to this point you’ve not done anything that could damage data on your hard drive. However, the next step involves booting the new kernel, so just to be safe one last time I’m going to recommend that you be sure you have a current backup of any important data that lives on your hard drive.
Step 8: Try your new kernel.
And now, the moment you’ve been waiting for.. It’s time to reboot your computer, and test your newly compiled 2.6 kernel. If you’ve done everything correctly, you’ll watch some friendly boot messages, and then be prompted to login. (If your booting to initstate=3, you’ll notice the new kernel immediately…)
If you installed ALSA for the first time, you can verify that your sound driver has properly loaded by typing ‘cat /proc/asound/cards’. For example:
$ cat /proc/asound/cards
0 [Live ]: EMU10K1 - Sound Blaster Live!
Sound Blaster Live! (rev.5) at 0x18e0, irq 11
If you see something like that, but sound still isn’t working, launch ‘alsamixer’ and be sure your device is turned up. I was confused at first in that turning up the ‘Master’ control wasn’t enough, I also had to turn up ‘PCM’ (/dev/dsp) for sound to start working.
Once you’ve tried out your new 2.6 kernel, I’d love if you’d post a comment here with your reflections. I’m also open to suggestions on how to make the above directions more useful.
If you run into problems with your new kernel, once again refer to the top-level ‘README’ that came with your kernel source which has a useful section titled “IF SOMETHING GOES WRONG”. Additionally, refer to the top-level ‘REPORTING-BUGS’ file if the need arises. Prior to posting problems to the high-traffic Linux kernel mailing list, be sure to search one or more of the many online lkml archives to see if someone else has already reported the problem, and better yet if someone else has already posted a fix. Last but not least, you may also try asking for help in the KernelTrap 2.6 kernel forum.
Additional tips/FAQs:
Thanks to a significant amount of reader feedback in the form of comments below and personal emails, I’m going to add a few random but hopeful useful tips to the end of this document. If you have additional tips, please feel free to send me an email. (If you’ve already sent a comment and I’ve note yet replied, please be patient…)
| Author : | dlb |
Description :
BricoPack Vista Inspirat is a free pack which modifies Windows XP system files in order to change its appearance and make it look like Windows Vista (the next operating system made by Microsoft).
Rewarded by a lot of magazine, Vista Inspirat BricoPack is the best way to change quickly and easily your Windows icons, logon and visual style.
Warning : the use of a BricoPack installed without following our instructions can make your system down. Before installing this BricoPack, please read the instructions page “about the BricoPacks”. You must not install this pack on Windows x64
I like the comment written by dlb about his own work… not so critical, but I have to say that it’s the truth!
The KDE Community is thrilled to announce the immediate availability of KDE 4.0. This significant release marks both the end of the long and intensive development cycle leading up to KDE 4.0 and the beginning of the KDE 4 era.
The KDE 4.0 desktop
The KDE 4 Libraries have seen major improvements in almost all areas. The Phonon multimedia framework provides platform independent multimedia support to all KDE applications, the Solid hardware integration framework makes interacting with (removable) devices easier and provides tools for better power management.
The KDE 4 Desktop has gained some major new capabilities. The Plasma desktop shell offers a new desktop interface, including panel, menu and widgets on the desktop as well as a dashboard function. KWin, the KDE Window manager, now supports advanced graphical effects to ease interaction with your windows.
Lots of KDE Applications have seen improvements as well. Visual updates through vector-based artwork, changes in the underlying libraries, user interface enhancements, new features, even new applications — you name it, KDE 4.0 has it. Okular, the new document viewer and Dolphin, the new file manager are only two applications that leverage KDE 4.0’s new technologies.
The Oxygen Artwork team provides a breath of fresh air on the desktop. Nearly all the user-visible parts of the KDE desktop and applications have been given a facelift. Beauty and consistency are two of the basic concepts behind Oxygen.
Learn more about KDE’s new desktop interface in the KDE 4.0 Visual Guide.
Some applications are introduced in more detail in the KDE 4.0 Visual Guide.
Filemanager, System Settings and Menu in action
KDE’s TechBase knowledge library has more information about the KDE libraries.
The KDE 4.0 Visual Guide provides a quick overview of various new and improved KDE 4.0 technologies. Illustrated with many screenshots, it walks you through the different parts of KDE 4.0 and shows some of the exciting new technologies and improvements for the user. New features of the desktop get you started, applications such as System Settings, Okular the document viewer and Dolphin the file manager are introduced. Educational applications are shown as well as Games.
For those interested in getting packages to test and contribute, several distributions have notified us that they will have KDE 4.0 packages available at or soon after the release. The complete and current list can be found on the KDE 4.0 Info Page, where you can also find links to the source code, information about compiling, security and other issues.
The following distributions have notified us of the availability of packages or Live CDs for KDE 4.0:
KDE 4.0 is the innovative Free Software desktop containing lots of applications for every day use as well as for specific purposes. Plasma is a new desktop shell developed for KDE 4, providing an intuitive interface to interact with the desktop and applications. The Konqueror web browser integrates the web with the desktop. The Dolphin file manager, the Okular document reader and the System Settings control center complete the basic desktop set.
KDE is built on the KDE Libraries which provide easy access to resources on the network by means of KIO and advanced visual capabilities through Qt4. Phonon and Solid, which are also part of the KDE Libraries add a multimedia framework and better hardware integration to all KDE applications.
KDE is an international technology team that creates free and open source software for desktop and portable computing. Among KDE’s products are a modern desktop system for Linux and UNIX platforms, comprehensive office productivity and groupware suites and hundreds of software titles in many categories including Internet and web applications, multimedia, entertainment, educational, graphics and software development. KDE software is translated into more than 60 languages and is built with ease of use and modern accessibility principles in mind. KDE4’s full-featured applications run natively on Linux, BSD, Solaris, Windows and Mac OS X.
Trademark Notices. KDE® and the K Desktop Environment® logo are registered trademarks of KDE e.V. Linux is a registered trademark of Linus Torvalds. UNIX is a registered trademark of The Open Group in the United States and other countries. All other trademarks and copyrights referred to in this announcement are the property of their respective owners.
http://www.kde.org/
Open Office 2.4 has a host of incremental changes with many new features and enhancements such as improvements in user interface, database, etc. We compared it with MS Office and also give you a hands-on tour
The word processor, i.e. Writer now includes an easier way to write in multiple languages other than the default language. Earlier, whenever you used multiple languages to write a document, it was very difficult to switch from one language to the other and to tell Writer which spell checker to use. Now you have three easy ways to run spell check on your doc. Just right click on the wrongly spelt word, go to ‘Select language for selection’ and select the language you want. Here, unlike earlier days when you had to select the word or the para and navigate all the way to the Font tab under Format > Character option, you can now simply switch amongst languages. Backreference has also been introduced in the ‘Replace with option,’ a useful feature that was earlier available only with the Search option. For example, you can change the data written in mm-dd-yyyy format to yyyy-dd-mm across the whole document. You can also select rectangular area of text in your document, similar to the ‘Alt’ + Click selection in MS Word.
Now you can export Draw and Impress page directly to PDFs and create bookmarks as per the name of the page, which will help easy navigation through pages. For example in Impress you can create slide names as bookmarks. Plus, new transition effects have been added. These include Flipping Tiles, Outside Turning Cube, Turning Helix, Rochade, etc.
The comparison
There are some differences between MS Office and OpenOffice. Here we make a comparison. The programmes in ‘MS Office Student and Home, (SAH) and OpenOffice are almost the same. But there are some uncommon applications between them, such as MS OneNote in MS Office SAH 2007 and Database (like MS Access) in OpenOffice. Again, MS Access 2007 is not included in MS Office student and home 2007 office suite. While OpenOffice is available for almost all platforms, like, Windows, Linux and Solaris, MS Office is available on Windows only.
MS Office 2007 uses less memory than OpenOffice 2.4. However, there is hardly any time difference between the two to load up (less than 1 sec).
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Memory consumption of OpenOffice apps is higher than MS Office. However, there wasn’t much difference in the loading times of both |
MS Word Vs OpenOffice Writer
Ribbons in MS Office 2007 provide easy navigation across different menu items. OpenOffice Writer supports the DOCX format of latest MS Word but you need to download ‘ODF converter-integrator’ to read/write a DOCX file. File compatibility issues exist between the two Office suites. We prepared a Word document with graphs; drew a bar chart, type ‘Clustered Pyramid,’ tables and a box, and when we opened the document in OpenOffice the bar chart and the box didn’t appear. But there were no changes as far as texts and tables are concerned.
We saved a file in DOC format in Writer and tried to open it in MS Word, it opened as it was. OpenOffice supports DOC format but MS Word 2007 does not support the ODF format, Plus ‘SmartArt’ of MS Office 2007 is not supported by Writer.
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A document in MS Office 2007 is created with a Word Art and a table and is opened in OO. The table got left aligned and the Word Art didn’t appear at all. The text remained as it is. |
MS Excel Vs OpenOffice Calc
Compatibility issues are also there when it comes to Excel and Calc. We created a table in MS Excel with one Bar chart and one Pie chart. The table and the charts opened perfectly fine, but the layout of both graphs changed a bit. Then we saved the file in XLS file format and reopened the file in MS Excel 2007. Both graph didn’t show up in MS Excel 2007, the chart area was blank. After that, we created a spreadsheet in MS Excel 2007, and opened it Calc. The spreadsheet opened fine.
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The compatibility issue is clearly visible in the above screenshot. The cone bar chart appears as 3D bar chart, and sliced pie chart appears as solid pie chart in OO, while the table remains the same |
MS PowerPoint Vs OpenOffice Impress
PowerPoint and Impress are also not without the compatibility issues. We created a slide with arrows, similes, text and 3D images, and applied slide design to it. We opened the presentation in Impress, everything appeared fine except the similes which didn’t appear at all. Then we inserted a bar chart in our presentation, and saved in PPT format. While opening the presentation in PowerPoint, everything appeared fine, including the bar chart.
From a cost alone perspective, Open Office is of course a better choice because you get so many features for free. But if you’re working in an environment where you have to share files with a lot of external people (which you most probably are), then your choice depends upon what everyone else is using. That’s because there are incompatibilities between the two, as we just saw.
To make this setup, you should have running Hotspot server on the router. Let us consider configuration steps for HotSpot and User Manager routers, in order to use User Manager for HotSpot users
/ ip hotspot profile set hsprof1 use-radius=yes
/ radius add service=hotspot address=y.y.y.y secret=123456
’secret’ is equal to User Manager router secret. ‘y.y.y.y’ is the User Manager router address. By default this is 127.0.0.1. If using a remotely located Router (perhaps via a VPN) then the IP address entered is the IP address of that remote Router. The router could be a Radius Server, or another ROS with User Manager installed.
It means that if you have configuration in ‘/ ip hotspot user print’, users will be able to authenticate in HotSpot using these data. Delete users configuration from ‘/ ip hotspot print’ to stop using local HotSpot database for authentication. To move batch of local HotSpot users to the User Manager database use export/import . Use text editor program to create appropriate file to import local users to the User Manager database.
/ tool user-manager customer add login="MikroTik" password="qwerty" permissions=owner
/ tool user-manager router add subscriber=MikroTik ip-address=x.x.x.x shared-secret=123456
‘x.x.x.x’ is the address of the HotSpot router, ’shared-secret’ should match on both User Manager and HotSpot routers. Adding ‘x.x.x.x’ as a router allows Radius requests from ‘x.x.x.x’ to be passed to the Radius Server built into User Manager. Therefore if you have any remote ROS Hotspots that require access to this Radius Server, then all their IP addresses must be added to this list.
/ tool user-manager user add username=demo password=demo subscriber=MikroTik
We discuss only basic configuration example, detailed information about ‘user’ menu configuration.
/ ip hotspot active print Flags: R - radius, B - blocked # USER ADDRESS UPTIME SESSION-TIME-LEFT IDLE-TIMEOUT 0 R 00:01:29:2... 192.168.100.2 1m29s
‘R’ means that client uses User Manager server for AAA services.
About chmodChanges the permission of a file.
chmod [OPTION]… MODE[,MODE]… FILE…
chmod [OPTION]… OCTAL-MODE FILE…
chmod [OPTION]… –reference=RFILE FILE…
| -c, –changes | like verbose but report only when a change is made |
| –no-preserve-root | do not treat `/’ specially (the default) |
| –preserve-root | fail to operate recursively on `/’ |
| -f, –silent, –quiet | suppress most error messages |
| -v, verbose | output a diagnostic for every file processed |
| –reference=RFILE | use RFILE’s mode instead of MODE values |
| -R, –recursive | change files and directories recursively |
| –help | display this help and exit |
| –version | output version information and exit |
Permissions
u - User who owns the file.
g - Group that owns the file.
o - Other.
a - All.
r - Read the file.
w - Write or edit the file.
x - Execute or run the file as a program.
Numeric Permissions:
CHMOD can also to attributed by using Numeric Permissions:
400 read by owner
040 read by group
004 read by anybody (other)
200 write by owner
020 write by group
002 write by anybody
100 execute by owner
010 execute by group
001 execute by anybody
The above numeric permissions can be added to set a certain permission, for example, a common HTML file on a Unix server to be only viewed over the Internet would be:
chmod 644 file.htm
This gives the file read/write by the owner and only read by everyone else (-rw-r–r–).
Files such as scripts that need to be executed need more permissions. Below is another example of a common permission given to scripts.
chmod 755 file.cgi
This would be the following 400+040+004+200+020+100+010+001 = 775 where you are giving all the rights but the capability for anyone to edit your file.cgi (-rwxr-xr-x).
Finally, another common CHMOD permission is 666, as shown below, which is read and write by everyone.
chmod 666 file.txt
Below is an example of how a file may be listed when typing ( ls -l ) at the prompt as well as information on how to interpret it.
-rw-rw-r– 1 hope 123 Feb 03 15:36 file.txt
| - | rw | rw- | r– | 1 | hope | 123 | Feb 03 15:36 | file.txt |
| File | owner | group | everyone else | links | owner | size | mod date | file name |
chmod [-fR] mode pathname …
chmod changes the access permissions or modes of the specified files or directories. Modes determine who can read, change or execute a file.
You can specify the mode value on the command line in either symbolic form or as an octal value.
A symbolic mode has the form
[who] op permission [op permission ...]
The who value is any combination of the following:
g sets group permissions. o sets other permissions. a sets all permissions; this is the default.
On Windows file systems, there are no group or other permissions. Therefore, they always match the individual permissions.
The op part of a symbolic mode is an operator that tells chmod to turn the permissions on or off. The possible values are:
- turns off a permission. = turns on the specified permissions and turns off all others.
The permission part of a symbolic mode is any combination of the following:
You can specify multiple symbolic modes if you separate them with commas.
Absolute modes are octal numbers specifying the complete list of attributes for the files; you specify attributes by OR’ing together these bits.
01000000 temporary file 02000000 compressed file 04000000 sparse file 4000 Hidden file (setuid bit) 2000 System file (setgid bit) 1000 Archive bit (sticky bit) 0400 Individual read 0200 Individual write 0100 Individual execute (or list directory) 0040 Group read 0020 Group write 0010 Group execute 0004 Other read 0002 Other write 0001 Other execute
This list shows the first three bits with their meanings on Windows systems and with their meanings on UNIX and POSIX-compliant systems in parentheses. The MKS version of chmod tries to handle options in a way that parallels the POSIX approach. In the following list, each line shows a group of calls that are equivalent.
chmod 0000 chmod o=s chmod 2000 chmod g=s chmod =s chmod 4000 chmod u=s chmod =h chmod 6000 chmod a=s chmod ug=s chmod =hs
To get a read-only file on Windows systems, you must turn off all three write permission bits; if any of the three is on, Windows considers the file to be writable.
On Windows systems, the lc and ls commands both indicate the mode settings of files. The Windows dir command does not show these attributes, and the attrib command may only work with the read-only attribute, depending on the version of your operating system.
chmod -w nowrite
makes file nowrite read-only.
chmod +hrs sysfile
sets the hidden, read-only, and system attributes for sysfile.
chmod a=rwx file
turns on read, write, and execute permissions, and turns off the hidden, archive, and system attributes. This is equivalent to
chmod 0777 file
On Windows NT/2000/XP/2003/Vista, the command
chmod -R +c d:/
compresses the D: drive.
Possible exit status values are:
chmod is provided as both an external utility and a built-in MKS KornShell utility.
POSIX.2. x/OPEN Portability Guide 4.0. Windows 2000. Windows XP. Windows Server 2003. Windows Vista.
Different systems interpret some mode bits in different ways.
The -f option as well as the a, c, h, and t permissions are extensions to the POSIX standard.
MKS Toolkit for Power Users
MKS Toolkit for System Administrators
MKS Toolkit for Developers
MKS Toolkit for Interoperability
MKS Toolkit for Professional Developers
MKS Toolkit for Enterprise Developers
MKS Toolkit for Enterprise Developers 64-Bit Edition
Need to integrate your Windows and Linux machines over a network? One tool that may help is VNC, a frame-buffer-based client/server application that lets you display desktops on remote networked machines, and which runs on all kinds of platforms, including Linux, Unix, Macs, Windows, and mainframes.
Most Linux distributions include some form of VNC. If you need to download, there are several versions to choose from, including RealVNC, TightVNC, and KDE’s Desktop Sharing, the VNC desktop server and client built into KDE.
VNC runs on all types of hardware, including laptops. I’m currently running SUSE Linux 8.2 on my puny 300MHz Pentium II no-name Taiwanese clone laptop. The VNC server that I used was SUSE’s 3.3.3r2-463 version, which came bundled on the CDs.
Before you can begin using VNC, you must set a password on the server side. You can do this and other VNC server-related tasks easily from the command line. As a regular user, in an xterm, type vncpasswd, followed by the password and the obligatory re-type. The password will be the same across multiple instances of the VNC server.
Starting the server is easy, too. In an xterm, as a regular user, type:
vncserverThe server will start and print something like:
fig New 'X' desktop is curley:2
Starting applications specified in /home/rreilly/.vnc/xstartup
Log file is /home/rreilly/.vnc/curley:2.log
This means that there is a new desktop available to VNC clients on the client machine with a display number of 2. You need this information to connect from the client. You can also express the machine and display number as an IP address, such as 192.168.2.24:2. (You can get the server IP by logging in as root and typing ifconfig.)
Vncserver can also be used with command-line options. For example:
vncserver -geometry 800x600 -depth 16 :4This command starts the server and sets the screen size to 800×600 pixels with a color depth of 16 on display number 4. You can also use more complicated options, such as setting the TCP port or turning off sharing.
You can set the default desktop look and feel by editing the xstartup file in your home .vnc directory.
With the VNC server up and running, let’s turn our attention to the VNC client side.
VNC on a Windows machine
As a demonstration of how slim VNC is on system resources, I pressed a vintage 200MHz Pentium Windows 98 machine into use as a VNC client. Obviously, screen refreshes would be better with higher-powered hardware. Many factors can affect performance, including server size, network bandwidth, and the applications running.
There are at least a couple of VNC clients that you can run on Windows: TightVNC and RealVNC. I tested both and saw no real difference between the two, except for cosmetics. TightVNC has two versions, Fast Compression and Best Compression. The Best Compression had horrendously slow repaint times. RealVNC lacks a compression option. So as not to be redundant, I’ll just describe the TightVNC operation.
When you start the client software, a little window appears and asks you for the server name. After you enter it and click OK, a password box appears for you to fill in.
When I’d entered my server’s IP address and password, I was greeted with a full screen view of my laptop’s desktop, as seen in Figure 1. I clicked around and even started up the Konqueror Web browser in full-screen mode. Slashdot took a few seconds to load, but it was very readable and reasonably snappy.
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To test multiple client connections to the VNC server, I started up the KDE Connection Sharing program on another laptop running Mepis Linux. The startup procedure on Linux was similar to starting the VNC client on Windows.
So there I was using a Linux desktop (running on my SUSE laptop) while seated at a Windows 98 machine, and at the same time my Mepis laptop simultaneously tracked my every movement of the mouse on its LCD screen.
You can click on the icon in the upper left corner of the VNC client window to bring up the program’s menu. You’ll find connection options, connection info, and the option to switch to full-screen mode. The best screen repaints seem to be with Hextile on and Allow CopyRect encoding turned off, under the connection options tab.
Similarly, with RealVNC, I turned off auto select on the colour/encoding tab and punched the Hextile radio button, to make the repaints a little faster. For really vivid colors you should use the full button in the color level section.
Browsing with VNC
If you like the VNC server and client software, you might also be interested in using VNC through a browser (Mozilla or Internet Explorer) to access a Linux desktop from a Windows machine.
Start up your browser, type in the URL of your VNC server and the port number, and away it goes, as long as you have Java loaded. If you don’t, the browser will ask you if you want to get the plug-in. Say yes and follow the directions to get it loaded.
The port number is a little tricky. The default is 5800. To use the :2 desktop from the server simply add the 2 to the 5800 number. So, my complete URL was:
http://192.168.2.24:5802/
As you would expect, Java took a minute or two to start, and then up popped the password box.
Again, I opened the Options tab (located on a little panel at the top of the browser window). Encoding was set to Hextile. I also changed use copyrect to no and raw pixel drawing to fast.
Performance after the initial page loading was very good, with vivid colors. Figure 2 shows Konqueror running on the Linux laptop, inside the Mozilla browser on the Windows 98 machine.
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Troubleshooting VNC
The main problems I’ve had with VNC are bad network connections. It’s easy to chase your tail trying to figure out what’s wrong if you are just getting started with the programs.
Always check to see that your VNC server is running. You can run ps -ax and look for a VNC-type line. Look for a line like this:
12920 pts/6 S 1:03 Xvnc :2 -desktop X -httpd /usr/share/vnc/classes -auth /home/rreilly/.Xauthority -geometry 1020×768
The next thing to check is to ping the server from the client machine. I used:
ping 192.168.2.24A response with a round trip time in the 8 to 12 ms. range is great. Of course, if you don’t get any round trip data, there is a problem with your network connectivity.
Wrap-up
VNC is a practical way to work on your Linux machine while you are on a Windows box. For more of an overview of VNC, see Russell Pavlicek’s “VNC: Virtually there and back again” article. Pavlicek talks about the different versions and their features.
If you want to see VNC in action, the Melbourne Linux User Group usually runs a VNC server, along with streaming audio and IRC sessions, during its meetings, so remote members can see what’s being discussed during a presentation. Find their IRC channel and they can help you get connected.
An interesting VNC-related program is vncrecord, which records all the keystrokes you make while doing work on the desktop.
Go try the VNC server and clients for yourself. They are easy to set up and are powerful tools for the mobile IT professional.
Rob Reilly is a consultant, writer, and commentator who advises clients on business and technology projects. His Linux, portable computing, and public speaking skills-related articles regularly appear in various high-end Linux and business media outlets.
By Rob Reilly