In the recent versions of Ubuntu, workspaces are disabled by default. Is there a specific reason for this.
I know how to enable them, but I wish to know the reason why the developers choose to disable them by default.
I wonder why Ubuntu won't remove the old kernels automatically.
Surely nothing is perfect and things can go wrong, so in case a update doesn't work, having a backup kernel maybe great. But it would also suffice to just keep the latest kernel and the one before the latest and delete all the older ones.
Is there a reason why Ubuntu won't do this automatically?.
Say I have a video of 5 minutes and I want to remove all audio from 1:00 to 2:00. Is this possible? If yes, how would I do this?
A question, Remove audio from mp4 file comes close to this but is closed as duplicate to best video converter. The answers this question only mention various video converters but don't provide any actual guideline on removing audio (which is what I want).
While installing Ubuntu with the "something else" option, I found out that there are many folders that can be mounted on separate partitions, as you can see in the image below.
So what are the advantages and disadvantages of mounting these folders(or directories) on separate partitions?
Specifically the directories are
/boot/home/tmp/usr/var/srv/opt/usr/local
I want to keep an eye on a file as it is created. So I used this command
ls -hal ./file |awk '{print $5}'
which gives the size of the file I am looking for. I use awk because I don't need other stuff, just the file size.
But I'm unable to use this with watch command, because if I try
watch ls -hal ./file |awk '{print $5}'
then watch only accepts ls -hal ./file and then pipes it to awk, giving no output.
If I try
watch "ls -hal ./file |awk '{print $5}'"
then it gets weird showing wrong command and whole output.
Every 2.0s: ls -hal ./file |awk '{print }' Sun Jul 20 15:52:18 2014
-rw-rw---- 1 aditya aditya 1.7K Jul 20 15:52 ./file
You can see there is no $5 in the awk command.
Further quoting creates various similar errors.
So what is the right way to quote this command?
According to this How to install software or upgrade from an old unsupported release? question, EOL releases are archived to http://old-releases.ubuntu.com.
But currently, I cannot see Ubuntu 12.10 and Ubuntu 13.04 to be available on this website, while all others(since 4.10) are available, as you can see in the screenshot below
So has canonical and/or Ubuntu devel-teams decided not to archive EOL releases any more? or is it work to be done?
When we try to install applications using sudo apt-get install command, we are asked for permission before installing as follows,
Need to get 9,979 kB/11.6 MB of archives.
After this operation, 36.8 MB of additional disk space will be used.
Do you want to continue [Y/n]?
But this happens only for packages above certain size(it's somewhere about 100 KB, but I'm not sure). For small packages it skips this step.
Why is it so?
Can I force apt-get to show the message on installation of all packages?
I am trying to run superoneclick using mono. I tried the following command
mono ./superoneclick.exe
I also tried
mono superoneclick.exe
But both give an error stating
Cannot open assembly 'superoneclick.exe': File does not contain a valid CIL image.
What should I do?
I know of one interrupt, i.e Ctrl+C which can be invoked by user in terminal.(can it be invoked elsewhere?)
Are there any other interrupts that can also be invoked by user?
In many cases, people do not take enough care to remove their IP addresses from some output before posting it to help forums and Q&A sites like askubuntu.
Considering one's IP address is revealed publicly, what are the possible threats he/she/bot may face and what can one do to avoid them?
Also, is there any threat in revealing other data like Broadcast address, Subnet mask, Default route, Primary DNS and Secondary DNS ?
Of course we will consider that the person/bot is using a supported version of Ubuntu or it's official derivatives.
When you type vi in the terminal, the following output is shown
~ VIM - Vi IMproved
~
~ version 7.3.547
~ by Bram Moolenaar et al.
~ Modified by [email protected]
~ Vim is open source and freely distributable
~
~ Help poor children in Uganda!
So according to this, vi must be launching VIm.
But when you type vim it gives
aditya@aditya-desktop:~$ vim
The program 'vim' can be found in the following packages:
* vim
* vim-gnome
* vim-tiny
* vim-athena
* vim-gtk
* vim-nox
Try: sudo apt-get install <selected package>
This shows that vim is not installed.
Notably man vi and man vim launch the same man pages.
So what does the vi command actually launch?
This seems to be a chicken-egg problem.
The most common task using sudo is installing and removing software.
sudo apt-get purge <appname>
But sudo itself can be removed.
sudo apt-get purge sudo # Do not run this command on production computers!
This is where the fun comes
ubuntu@ubuntu:~$ sudo
bash: /usr/bin/sudo: No such file or directory
Although it's obvious that no person in his right mind will purge sudo (other than me), someone can be fooled to run this command (not directly, in its hex mode, or whatever it's called) or a person could SSH in disguised as tech guru and do the mess.
So is there a way of reinstalling sudo?
We all know(or will know one day) that Ubuntu(or GNU/Linux in general) does not work with extensions of file to recognize what kind of file it is.Rather it uses Magic Numbers.
A Magic Number is a number associate with every Linux file and is generally the first few bytes of the file, which identifies the file type. It is used by the Linux command line utility file which displays the information related to a file.
So when we check a file type with the file command, it gives appropriate file type regardless of it's extensions.
So a mp3 file gives
aditya@aditya-desktop:~/Music$ file 'music.mp3'
music.mp3: Audio file with ID3 version 2.3.0, contains: MPEG ADTS, layer III, v1, 64 kbps, 44.1 kHz, JntStereo
aditya@aditya-desktop:~/Music$ file 'music'
music: Audio file with ID3 version 2.3.0, contains: MPEG ADTS, layer III, v1, 64 kbps, 44.1 kHz, JntStereo
aditya@aditya-desktop:~/Music$ file 'music.txt'
music.txt: Audio file with ID3 version 2.3.0, contains: MPEG ADTS, layer III, v1, 64 kbps, 44.1 kHz, JntStereo
aditya@aditya-desktop:~/Music$
The same expt , when tried with Nautilus, it considers the file a music file when it has .mp3 or no extension, but when it is given .txt extension, it considers it a text file.
So the main question,
- Does nautilus use extensions to recognize file?
- How can I force nautilus to ignore extensions and use magic numbers?
The default alias Alert is for the command
notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"
Executing alert gives an notification with text Alert and an terminal icon.
Executing it with one param like alert !!!!! gives notification with text Alert !!!!! and !!!!!.
So, what's the difference between simple notify-send command and this complexed alias which uses notify-send, echo, history, tail and sed?
In which situations is this alias useful or was it just created for pun(Something like using sudo sudo sudo sudo sudo apt-get install
I'm using Ubuntu 12.10
I have used shutter and screenshot applications for a long time for taking screenshots.But they can only take screenshots as big as the physical screen.
Sometimes I have to take an screenshot of an whole webpage,because the page can't be saved properly by the browser or I want to include pop-up's as well.This situation requires a software that can take a screenshot longer than the physical screen.
Is there any software to do this?
Note that this question and it's answers are about webpage saving apps.They won't save pop-up's, which is essential in my case.I don't want a converter.I need an literal screenshot app or anything that could save the pop-up's as well.
And I use Mozilla Firefox, because it has really nice plugins.The solution should be working fot Firefox itself.
Since I have moved from Windows XP to Ubuntu 12.10, I have been constantly blamed for increased electricity bills.(That may be true, but I think the reason is increase in the time I use my computer, because it is more productive now).
Is there any software that would calculate how much power my computer actually uses?
Note that I use a Desktop and the Powertop, Powerstat, and Power Statistics programs referenceed here only work for laptops. The answer suggests that for desktop the only solution "then" is to use a electronic watt-meter. Has the situation changed in last 2 years?
After going through the Home Page of Ubuntu Kylin, I rather find no considerable difference between Ubuntu Kylin and Ubuntu with Chinese language set as default.
There are of course some special Chinese apps (Chinese lunar calendar, for example); but can't these apps be installed on Ubuntu as well?
So if I get an Ubuntu, customize it to have all the same apps as Kylin, and set Chinese as default language, what will be the difference between both?
What was the need of kylin, when ubuntu is itself so customizable?
There is no bad in bringing an custom Ubuntu for Chinese people.But there seems to be no reason for making it official.If we look at other official distros like lubuntu or xubuntu, they have a significant difference than ubuntu.This is not the case with kylin.It would only take, say 15 minutes to convert Ubuntu into Ubuntu Kylin.
I have just started using Lynis (please don't think I have misspelled Linux). After running it, I was suggested to set umask in /etc/login.defs and /etc/init.d/rc to 027 than the default 022.
I want to know what changes that would make to file permissions. Also why is the value stored in two files? Do they work differently?
For more info if necessary, I use Ubuntu 12.10, and I am the only user of the system.
Many server administrators want their server to be used only by humans and not by retrieval programs like wget. One way to block such programs is to use log analysis. Log analysis identifies retrieval programs by looking for statistically significant similarities among the requests, often through timing.
Whenever I try to use wget to download packages through a shell script (one similar to those created by synaptic, mostly they are actually created by synaptic), only a few packages are downloaded and most of the packages fail to download due to connection refusal.
So I strongly think that the most probable reason why the connection is refused is that Ubuntu servers use log analysis to block programs.
Do Ubuntu servers use log analysis to block (package retrieval) programs?
EDIT:
I executed some scripts which contained packages of small size (i.e., they would get downloaded in less time). Such scripts work properly as expected. The error comes up with packages that are large in size (consequently they take more time).
Firefox was loading very slow, so I decided to use wget to save HTML files.I used the following command,
wget http://textbook.s-anand.net/ncert/class-xii/chemistry/hello-this-first-chapter
The files have been saved in my home folder.But I don't know where the images are stored.I need them to use in Anki.
So where are the images stored?