Install prelink, configure it via/etc/prelink.conf so that it covers the directories where KDE lives, then run it. KDE apps should start much, much quicker.
I don't think this has anything to do with swap, because if you open an app, close it, then open it again, it should be in RAM cache, so any startup time is down to:
1. Run-time linking - which takes ages for C++ apps without prelink, due to the huge number of symbols. 2. The app doing its own initialisation.
I think prelink should help for Mozilla too, as it's written mostly in C++ AFAIK.
One point I haven't seen raised yet is that this is very useful where you send your app out to customers with MSDE (cut-down SQL Server) and a ready-to-use database in the bundle.
Having the whole thing encrypted stops competitors taking your 'business logic' (in your stored procedures) home for bedtime reading. If you keep some stuff unavailable until they buy licenses for it, you can stop them seeing how to 'switch it on' , too.
1 bowl, medium size 1 pack of cornflour (presumably cornstarch is the US word for cornflour) 1 source of water
Put approximately 'some' cornflour in the bowl. Add water and stir until you have a liquid.
Mess about with the amounts of water and cornflour until you have a reasonably thin liquid, but one which if you punch (!) will not splatter all over the place. If you stir it with a spoon, very slowly, it will feel like water. If you try and stir it fast, you will feel great resistance.
You may want to try the spoon test before the punch test.
The scientific name for this substance is 'gloop'.
It's unclear that it's a good idea for something like KDE to do this because many malloc implementations already do it for you. Building this sort of functionality in user code generally does a worse job than when it's integrated into the memory allocator.
KDE uses dlmalloc, slightly patched to add some spinlocks. glibc uses dlmalloc now, apparently, so the speed advantage has probably gone away on Linux.
There's a way to avoid many mallocs/frees all at the same time, which is to use a memory pool and have some object look after it. Allocations usually come from an already allocated pool of memory, deallocations are simply the setting of a flag.
The object handling the pool keeps some free space in the pool so that a burst of new small allocations won't cause a 'real' malloc.
This technique is used by KDE. It's all done behind the scenes, so as a developer, you don't need to worry about it too much.
I upgraded my sound card from an Ensoniq 1371 (SoundBlaster PCI 128) to a Terratec DMX XFire 1024. When I play anything (including Windows' sounds) in Windows XP, the machine spontaneously reboots. Works perfectly in Linux.
I tried using the motherboard's inbuilt sound (CMIPCI) in XP, instead. It works ok most of the time, but occasionally games lock up. Turning off sound in games fixes the lock ups. Works perfectly in Linux.
I was a bit sick of this, so I removed my flashy new sound card (the Terratec) and replaced it with the old Ensoniq. Playing sounds in XP gives a loop over the first approx 0.2s of the sound, forever.
So I'm just not using XP anymore. It doesn't seem to support mainstream sound cards. Linux supports them out-of-the-box, and I didn't even have to download a driver for the Terratec.
Is this XP's achilles heel? No. It's just good old fashioned incompatibility problems. There are probably hundreds of thousands of different devices for PCs. They are combined with each other in a myriad of variations. No operating system is able to resolve every conflict that occurs.
I'm hoping that in the future, there will be more standards for hardware devices, following on from Good Things like USB Mass Storage, which has allowed people to carry USB flash devices around without too much worry of them not working on some PCs.
UNICODE_STRING
WARNING: THIS CLASS IS A WORK IN PROGRESS. SOME FEATURE ARE NOT YET IMPLEMENTED AND SOME FEATURE MAY APPEAR/DISAPPEAR.
Mature, fully-integrated Unicode support is in my top ten 'must have' features for a development system/language. I would think it should be in the Gnome project's, too.
Of course, C doesn't have built-in Unicode, but I'd guess that Gnome uses some library for it, as KDE uses Qt. In KDE, QString is used for 99.99% of strings and is a Unicode string. C-style strings (QCString) are only used for compatibility.
One of the things keeping me from doing more with Ruby is the fact that its String class doesn't do Unicode. I managed some hack, storing UTF-8 and converting with libiconv, but then I have to think about portability, etc. etc.
There is very little documentation about what DCOP interfaces programs like Kate have, and how they can be used for writing small scripts and macros.
I just figured this out by typing 'dcop kate' and then looking at what was printed.
$ dcop kate KateDocumentManager openURL/etc/passwd '' DCOPRef(kate, KateDocument#3) $ dcop kate EditInterface#3 numLines 61 $ dcop kate EditInterface#3 insertLine 61 blah true
Wasn't that hard, really. I do know what a DCOPRef is though, so I had a head start. My point is that you don't really need documentation for this sort of thing.
The existing DCOP interfaces are not designed for the ease of use by scripters/powerusers. They are built directly on top of the C++ implementation.
Er, what?
The DCOP interfaces are often not complete enough to make it possible to script everything that can be done via the GUI.
The only way you're going to get that level of scripting ability is to rewrite all apps in some interpreted language with remote method invocation and, to make life easier, reflection.
Rik
Re:Viruses on Linux? Yeah, right.
on
Linux in Canada
·
· Score: 2, Insightful
Rubbish. You don't need root access to 'infect' a Linux box. It would be very easy to write a virus which deletes all the user's files, sends itself to everyone in their addressbook, listens on a port, joins in DDoS, etc. All without root access.
The main difficulty faced by someone writing a virus for Linux is getting someone to run it in the first place. It's pretty hard to persuade a KMail user, for example, to execute a virus. They have to save an attachment and give it execute permission first.
Official ISO standard for what? Great Britain is an island. The United Kingdom is a country. Northern Ireland is a province, England and Scotland are Kingdoms, Wales is a principality.
People usually talk in terms of countries, so what are the ISO people using Great Britain for, I wonder?
How awfully nice for you. May we therefore assume that you're more clever than the rest of us?
Object orientation as a language prescription is a bad idea: At the time, every other GUI programming method used messages. From Xlib through to Win32, all GUI programming methods use messages. It is considerably easier to thread a program that does not have a GUI wrapped up inside of a object than one that does not.
Qt uses messages. Did you really use Qt or are you making this up?
What makes it easier to thread a program that does not 'have a GUI wrapped up inside of an object' [sic]?
Object orientation brings bloat: often students would go way overboard in designing a solution, using 30 classes where 5 would suffice.
What is so terrible about having a large number of classes? Only the most novice (OO) programmers I've met shy away from creating more than the 'bare minimum' of classes.
What does this have to do with Qt, anyway?
Compilers are not good at OO: compared to C, C++ compilers are immature and buggy. Sure, this is a compiler issue not a toolkit issue, but I found it frustrating debugging student's choice of compiler rather than choice of code.
This is plain wrong. There are some great C++ compilers out there and some servicable ones. Intel's C++ compiler and GNU G++ are examples of the former, Microsoft's of the latter. Why did you let students choose their own compiler?
Thankfully, the GTK+ toolkit is winning the battle of the GUI toolkits. Students these days feel much more grounded in reality when they see their favourite applications such as mozilla, gaim, xchat, and xmms using the same toolkit they do.
That first sentence is flamebait; the second is inaccurate. Mozilla isn't built on GTK+: perhaps you meant Firefox?
The idea of using XML to describe a user interface is nothing new, though that's not a criticism of Microsoft.
I think KDE is a good example of how XML can be used in this way successfully. KDE uses XMLGUI to describe the menus and toolbars of a window, for example, here's Konqueror's menu and toolbar structure.
Qt designer gives the XML a little more power, allowing you to set up connections between GUI elements within the XML itself. For example, you may specify that you will have a method named, e.g. 'addButtonClicked' and make a connection from your 'add' button to that method inside designer, by drawing a line. This connection will then appear in your code at runtime. All you do is implement the method and wait for it to be called. Examples of this can be seen in the above mouse configuration dialog XML.
Get up every day at 6am, iron a shirt, put on your suit. Walk half a mile to the bus stop, stand in cold for 20 minutes. Get a bus to somewhere miles away. Get off, stand in cold for 20 minutes again and get bus back. Walk half mile back to house. It should now be about 9am.
Decorate your 'office' with a stained carpet (preferably one made of carpet tiles,) a strip light that flickers and a vending machine which serves not-even-close-to-being-coffee.
Place a proxy between yourself and the web, pointlessly block any sites that may have useful information relevant to your job. Only allow yourself to unblock them after a week-long argument with yourself via email.
If you smoke, don't do it in the building. Stand outside (in the cold) and move at least 100 yards up the street, to avoid tarnishing your company's corporate image.
Have daily meetings, where the main topic should always be how to cut down on meetings so that actual work can be done.
At lunchtime, take another cold 20 minute walk to the local newsagent, who will be happy to supply you with a disturbingly cold sandwich from their fridge. The only one left will be egg.
Walk back to work, eating your sandwich and smoking at the same time, for efficiency and to hide the taste of the sandwich.
Every 10 minutes, pick up the phone and say 'Oh, you should have gone through to reception. Let me put you through... Oh, they're not answering. Can I take a message?' After this, scrawl something on a post-it note and wander around the 'office' for 10 minutes to simulate finding the message recipient's desk.
At the end of the day, leave the office and perform the bus trips again.
You say Linux/Qt needs a lot of work to become as functional and polished as Symbian, so I'm assuming you have used one of these phones as it's the only one around that uses Linux and Qt so far. What's it like? I haven't found any reviews yet.
I recently acquired a Philips ToUCam Pro 740. It works perfectly with Linux. It was a breeze to make work. Anticipating its arrival, I changed my kernel config to include the Philips webcam module(s). If you're using some nice dist like SuSE, you may have them already built.
When the cam arrived, I just plugged it in and started gnomemeeting. It worked.
It works very well in low light, which is handy if you like to work in semi darkness sometimes.
Release of large quantities of methane could cause interesting effects, but I'm not sure exactly what effects they would be.
Some methane rises to the stratosphere and becomes CO2 and water vapour. Is the amount of methane likely to be released under such a scenario going to have significant effect on these?
Some methane oxidises in the troposphere, removing oxygen. That water vapour in the stratosphere eventually gives oxygen back, so should we expect a net gain or loss of oxygen? I'm guessing a loss, but would this be balanced by other effects?
If you're using Konqueror, the pdf just opens in the same window, thanks to kghostview's kpart. Konqy's menus and toolbar also change to reflect the new things you can do.
If you're using Mozilla or IE, a similar thing happens using acrobat reader, without the integration bit.
If you're talking about text-based browsers, I'm not sure what they do, but if I used them, I'd set them up to give me two options: 1. Save to disk. 2. Run through pdf2text and display it.
Having said this, I agree that html is a better idea. I can override the CSS to make the page more readable for myself, when I resize the window word wrap adjusts the lines so they're still readable, etc.
I followed the same route, here's a brief rundown of what happened.
I found a project that interested me (KDE) and started trying to write my own program for it. I tried to made a graphical version of videogen, which is an XFree86 modeline generator. My version made it a little easier to play with combinations of the various parameters, and therefore scratched my personal itch. IIRC I announced it on freshmeat and got a few emails from people who wanted assistance or to request features.
Now that I had a little experience with writing for KDE, I made my own version of the classic game 'sokoban.' KDE and Qt made this really easy (even for me as a beginner) and I had it usable in a few days, though I hadn't noticed that there was already a sokoban clone in the pipeline for inclusion into KDE, so that little app died off.
At this point, I decided that kmail wasn't as good as I would like, and decided to try and help out, but I was about to lose my internet connection for some months and didn't feel that my skills were good enough to be actually putting code into live KDE apps, so I started my own mail client from scratch.
By the time I got my internet connection back, I had more confidence and started coming up with patches for KDE. From this point, I got more involved with the project and the community. I have my own application in the network module now, and though I don't have time to work on KDE actively right now, the skills I learned have helped me get my current job (where I get to use Qt, which is great for me.)
I would definitely recommend the route of scratching your itches and getting involved with a large project, assuming you are comfortable working in such an environment.
Slashdot Mirror
Ever heard of VMWare or Virtual PC? As for MacOS, well, they have Safari, which is basically KHTML of Konqueror, and Mozilla.
Oh yes, and as another poster said, stick to the standard.
Rik
Did you try prelink?
/etc/prelink.conf so that it covers the directories where KDE lives, then run it. KDE apps should start much, much quicker.
Install prelink, configure it via
I don't think this has anything to do with swap, because if you open an app, close it, then open it again, it should be in RAM cache, so any startup time is down to:
1. Run-time linking - which takes ages for C++ apps without prelink, due to the huge number of symbols.
2. The app doing its own initialisation.
I think prelink should help for Mozilla too, as it's written mostly in C++ AFAIK.
Rik
One point I haven't seen raised yet is that this is very useful where you send your app out to customers with MSDE (cut-down SQL Server) and a ready-to-use database in the bundle.
Having the whole thing encrypted stops competitors taking your 'business logic' (in your stored procedures) home for bedtime reading. If you keep some stuff unavailable until they buy licenses for it, you can stop them seeing how to 'switch it on' , too.
Rik
It's gravity. I have a theory for it, but I'm not a respected physicist so I'll keep it to myself so I don't get laughed at.
Rik
Just wondering how you know that it was reiserfs that messed up your vmware 'partitions' and your gnome settings.
If programs don't take care when writing to disk, you'll get corrupt data, no matter what the file system, when your power goes out.
Rik
Equipment needed:
1 bowl, medium size
1 pack of cornflour (presumably cornstarch is the US word for cornflour)
1 source of water
Put approximately 'some' cornflour in the bowl.
Add water and stir until you have a liquid.
Mess about with the amounts of water and cornflour until you have a reasonably thin liquid, but one which if you punch (!) will not splatter all over the place. If you stir it with a spoon, very slowly, it will feel like water. If you try and stir it fast, you will feel great resistance.
You may want to try the spoon test before the punch test.
The scientific name for this substance is 'gloop'.
Rik
It's gravity.
Rik
KDE uses dlmalloc, slightly patched to add some spinlocks. glibc uses dlmalloc now, apparently, so the speed advantage has probably gone away on Linux.
Rik
There's a way to avoid many mallocs/frees all at the same time, which is to use a memory pool and have some object look after it. Allocations usually come from an already allocated pool of memory, deallocations are simply the setting of a flag.
The object handling the pool keeps some free space in the pool so that a burst of new small allocations won't cause a 'real' malloc.
This technique is used by KDE. It's all done behind the scenes, so as a developer, you don't need to worry about it too much.
Rik
I upgraded my sound card from an Ensoniq 1371 (SoundBlaster PCI 128) to a Terratec DMX XFire 1024. When I play anything (including Windows' sounds) in Windows XP, the machine spontaneously reboots. Works perfectly in Linux.
I tried using the motherboard's inbuilt sound (CMIPCI) in XP, instead. It works ok most of the time, but occasionally games lock up. Turning off sound in games fixes the lock ups. Works perfectly in Linux.
I was a bit sick of this, so I removed my flashy new sound card (the Terratec) and replaced it with the old Ensoniq. Playing sounds in XP gives a loop over the first approx 0.2s of the sound, forever.
So I'm just not using XP anymore. It doesn't seem to support mainstream sound cards. Linux supports them out-of-the-box, and I didn't even have to download a driver for the Terratec.
Is this XP's achilles heel? No. It's just good old fashioned incompatibility problems. There are probably hundreds of thousands of different devices for PCs. They are combined with each other in a myriad of variations. No operating system is able to resolve every conflict that occurs.
I'm hoping that in the future, there will be more standards for hardware devices, following on from Good Things like USB Mass Storage, which has allowed people to carry USB flash devices around without too much worry of them not working on some PCs.
Rik
From the SmartEiffel documentation:
Mature, fully-integrated Unicode support is in my top ten 'must have' features for a development system/language. I would think it should be in the Gnome project's, too.
Of course, C doesn't have built-in Unicode, but I'd guess that Gnome uses some library for it, as KDE uses Qt. In KDE, QString is used for 99.99% of strings and is a Unicode string. C-style strings (QCString) are only used for compatibility.
One of the things keeping me from doing more with Ruby is the fact that its String class doesn't do Unicode. I managed some hack, storing UTF-8 and converting with libiconv, but then I have to think about portability, etc. etc.
Wow, I'll be checking that out soon!
Rik
I just figured this out by typing 'dcop kate' and then looking at what was printed.
Wasn't that hard, really. I do know what a DCOPRef is though, so I had a head start. My point is that you don't really need documentation for this sort of thing.
Er, what?
The only way you're going to get that level of scripting ability is to rewrite all apps in some interpreted language with remote method invocation and, to make life easier, reflection.
Rik
Rubbish. You don't need root access to 'infect' a Linux box. It would be very easy to write a virus which deletes all the user's files, sends itself to everyone in their addressbook, listens on a port, joins in DDoS, etc. All without root access.
The main difficulty faced by someone writing a virus for Linux is getting someone to run it in the first place. It's pretty hard to persuade a KMail user, for example, to execute a virus. They have to save an attachment and give it execute permission first.
Rik
Official ISO standard for what? Great Britain is an island. The United Kingdom is a country. Northern Ireland is a province, England and Scotland are Kingdoms, Wales is a principality.
People usually talk in terms of countries, so what are the ISO people using Great Britain for, I wonder?
Rik
But it's speed reduction, so...
100% = 1/2 the time.
200% = 1/2 of 1/2 the time, which is 1/4 the time.
300% = 1/8 the time.
1000% = 1/1024 the time.
Which is a 1023/1024 improvement, or only 0.999x, so disk access is in fact slightly slower!
Yes, I'm really bad at maths.
Rik
Because you are a coward?
How awfully nice for you. May we therefore assume that you're more clever than the rest of us?
Qt uses messages. Did you really use Qt or are you making this up?
What makes it easier to thread a program that does not 'have a GUI wrapped up inside of an object' [sic]?
What is so terrible about having a large number of classes? Only the most novice (OO) programmers I've met shy away from creating more than the 'bare minimum' of classes.
What does this have to do with Qt, anyway?
This is plain wrong. There are some great C++ compilers out there and some servicable ones. Intel's C++ compiler and GNU G++ are examples of the former, Microsoft's of the latter. Why did you let students choose their own compiler?
That first sentence is flamebait; the second is inaccurate. Mozilla isn't built on GTK+: perhaps you meant Firefox?
The parent post smells funny. I call shenanigans.
Rik
Excuse my ignorance, but why is this better than just letting the liquid flow over the entire wall?
The idea of using XML to describe a user interface is nothing new, though that's not a criticism of Microsoft.
I think KDE is a good example of how XML can be used in this way successfully. KDE uses XMLGUI to describe the menus and toolbars of a window, for example, here's Konqueror's menu and toolbar structure.
KDE also uses XML to describe the 'work' area of windows. The XML is created by Qt designer. Example: kcontrol's mouse configuration dialog.
Qt designer gives the XML a little more power, allowing you to set up connections between GUI elements within the XML itself. For example, you may specify that you will have a method named, e.g. 'addButtonClicked' and make a connection from your 'add' button to that method inside designer, by drawing a line. This connection will then appear in your code at runtime. All you do is implement the method and wait for it to be called. Examples of this can be seen in the above mouse configuration dialog XML.
Get up every day at 6am, iron a shirt, put on your suit. Walk half a mile to the bus stop, stand in cold for 20 minutes. Get a bus to somewhere miles away. Get off, stand in cold for 20 minutes again and get bus back. Walk half mile back to house. It should now be about 9am.
Decorate your 'office' with a stained carpet (preferably one made of carpet tiles,) a strip light that flickers and a vending machine which serves not-even-close-to-being-coffee.
Place a proxy between yourself and the web, pointlessly block any sites that may have useful information relevant to your job. Only allow yourself to unblock them after a week-long argument with yourself via email.
If you smoke, don't do it in the building. Stand outside (in the cold) and move at least 100 yards up the street, to avoid tarnishing your company's corporate image.
Have daily meetings, where the main topic should always be how to cut down on meetings so that actual work can be done.
At lunchtime, take another cold 20 minute walk to the local newsagent, who will be happy to supply you with a disturbingly cold sandwich from their fridge. The only one left will be egg.
Walk back to work, eating your sandwich and smoking at the same time, for efficiency and to hide the taste of the sandwich.
Every 10 minutes, pick up the phone and say 'Oh, you should have gone through to reception. Let me put you through... Oh, they're not answering. Can I take a message?' After this, scrawl something on a post-it note and wander around the 'office' for 10 minutes to simulate finding the message recipient's desk.
At the end of the day, leave the office and perform the bus trips again.
Rik
Qtopia Phone Edition is likely to appear on a phone soon.
The Motorola A760 is using Linux/Qt, not Qtopia Phone Edition, but it's basically the same thing.
You say Linux/Qt needs a lot of work to become as functional and polished as Symbian, so I'm assuming you have used one of these phones as it's the only one around that uses Linux and Qt so far. What's it like? I haven't found any reviews yet.
Rik
I recently acquired a Philips ToUCam Pro 740. It works perfectly with Linux. It was a breeze to make work. Anticipating its arrival, I changed my kernel config to include the Philips webcam module(s). If you're using some nice dist like SuSE, you may have them already built.
When the cam arrived, I just plugged it in and started gnomemeeting. It worked.
It works very well in low light, which is handy if you like to work in semi darkness sometimes.
Rik
Release of large quantities of methane could cause interesting effects, but I'm not sure exactly what effects they would be.
Some methane rises to the stratosphere and becomes CO2 and water vapour. Is the amount of methane likely to be released under such a scenario going to have significant effect on these?
Some methane oxidises in the troposphere, removing oxygen. That water vapour in the stratosphere eventually gives oxygen back, so should we expect a net gain or loss of oxygen? I'm guessing a loss, but would this be balanced by other effects?
Rik
If you're using Konqueror, the pdf just opens in the same window, thanks to kghostview's kpart. Konqy's menus and toolbar also change to reflect the new things you can do.
If you're using Mozilla or IE, a similar thing happens using acrobat reader, without the integration bit.
If you're talking about text-based browsers, I'm not sure what they do, but if I used them, I'd set them up to give me two options: 1. Save to disk. 2. Run through pdf2text and display it.
Having said this, I agree that html is a better idea. I can override the CSS to make the page more readable for myself, when I resize the window word wrap adjusts the lines so they're still readable, etc.
Rik
I followed the same route, here's a brief rundown of what happened.
I found a project that interested me (KDE) and started trying to write my own program for it. I tried to made a graphical version of videogen, which is an XFree86 modeline generator. My version made it a little easier to play with combinations of the various parameters, and therefore scratched my personal itch. IIRC I announced it on freshmeat and got a few emails from people who wanted assistance or to request features.
Now that I had a little experience with writing for KDE, I made my own version of the classic game 'sokoban.' KDE and Qt made this really easy (even for me as a beginner) and I had it usable in a few days, though I hadn't noticed that there was already a sokoban clone in the pipeline for inclusion into KDE, so that little app died off.
At this point, I decided that kmail wasn't as good as I would like, and decided to try and help out, but I was about to lose my internet connection for some months and didn't feel that my skills were good enough to be actually putting code into live KDE apps, so I started my own mail client from scratch.
By the time I got my internet connection back, I had more confidence and started coming up with patches for KDE. From this point, I got more involved with the project and the community. I have my own application in the network module now, and though I don't have time to work on KDE actively right now, the skills I learned have helped me get my current job (where I get to use Qt, which is great for me.)
I would definitely recommend the route of scratching your itches and getting involved with a large project, assuming you are comfortable working in such an environment.
Rik