Why do I need sudo to reboot from the command line?
Why do we need to be root in terminal for shutdown and restart?
The latest kernel is causing problems with my sound, which worked fine with an older version. As I have only Ubuntu installed, Grub is not getting displayed while booting. How can I manually choose my kernel version while booting? Search [tag1] OR [tag2] Is there a way to search questions that are tagged with either tag1 or tag2?  Actually, I would like the general filter,      ([tag1] AND [tag2], ...) OR ([tag3]   AND [tag4], ...) OR ...   And even     [tag1] AND ([tag2] OR [tag3])   I need that because I'm looking for interesting questions and I have to search for each tag separately. I'm looking for one word which describes what a student who missed classes needs to do Why is moving directories to /dev/null dangerous? Transparent model when exporting fbx file to Unity So I have this shark model which I animated and ready to export it on fbx and transport it to Unity.  But When I put it on Unity, It looks transparent like this.    Many of the solutions online say that the problem is because of my faces, and they told me to recalculate it or something, but normals are just fine. Is there any other solution?  here's the blend file: Is TV harmful to my infant's development? Automorphism group of the quaternion group How do regular expressions differ from wildcards used to filter files I define a shell keybinding in my ~/.bashrc like so:  bind -x '"\e\C-w":"/usr/bin/reset"'   This does make Ctrl-Alt-w launch the reset executable. However, it leaves the terminal in a state that resembles the one you get into by pressing Ctrl-v. So, for example, if immediately after resetting in this way I press Ctrl-p, instead of invoking the action of that shortcut (repeat previous command) I get ^P printed.  Any idea what's causing this problem and how to fix it?  EDIT: I am attaching a Python program that reproduces the messed-up terminal state I am trying to fix with the reset. I encounter this condition very often while debugging multi-threaded applications:  import pdb, thread, time  def interrupt():     time.sleep(2)     pdb.set_trace()  thread.start_new_thread(interrupt, ()) raw_input('? ')   To reproduce the messed-up state, just run the code above, and press Enter when you see the debugger invoked (it will print a bunch of text, ending with pdb.set_trace(), about two seconds after you run the program and the initial prompt appears). What if I accidentally run command "chmod -R" on system directories (/, /etc, ...) I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back? Proving the so-called "Well Ordering Principle" How to define global functions in PHP I am running 12.04 LTS. It's a pretty default installation and is the only OS on this machine.  I have two users one has administrator rights the other does not. I accidentally removed administrator rights from the "admin" user.  I tried to  but that requires reaching GRUB during boot but I cannot get there because my /etc/default/grub has GRUB_HIDDEN_TIMEOUT=0 and changing that to a positive integer requires admin privileges to save the changes and run sudo update-grub.  Should I boot from LiveCD? The  discouraged my a bit. Right now all I have handy is an install DVD from 11.10, but that did not help me much.  Not sure what to do now.  Any suggestions?  NOTE: 12.04 does not have an admin group and I have not enabled root Proof that every metric space is normal Proper fstab entry to mount a samba share on boot? I am a little confused on the proper fstab entry for a samba share in Ubuntu 12.04     I can get the drive to mount manually by using:  sudo mount -t cifs //192.168.2.2/raid_drive /mnt/homeserver -o username=jon,password=password  So I tried putting this in fstab:  //192.168.2.2/raid_drive /mnt/homeserver cifs username=jon,password=password,iocharset=utf8,mode=0777,dir_mode=07‌​77 0 0  Which gives me this error in syslog:  kernel: [ 2217.925354] CIFS: Unknown mount option mode kernel: [ 2217.936345] CIFS VFS: default security mechanism requested.  The default security mechanism will be upgraded from ntlm to ntlmv2 in kernel release 3.3  This  says to use smbfs although I believe smbfs is deprecated?   What is a common fstab configuration for a samba share in Ubuntu 12.04?   EDIT:  Using the accepted answer below I was initially getting this error message (from dmesg):  [   45.520883] CIFS VFS: Error connecting to socket. Aborting operation [   45.520990] CIFS VFS: cifs_mount failed w/return code = -115   although it turns out this was due to network connectivity issues, and not related to improper fstab entry. Can you teleport farther away with misty step if you have a double from Invoke Duplicity? The Channel Divinity feature says:     you can cast spells as though you were in the illusion's space, but   you must use your own senses. (PHB 63)   If you were where your duplicate is, you could step to a space 30ft from its position. So if it is 60ft from you, you could teleport to a space 90ft from your actual position. But the spell says that:     you teleport up to 30 feet (PHB 260)   This would put a hard limit on the distance you can travel.  Which rule takes precedence here? I wonder if someone knows any general rules of thumb regarding the number of bootstrap samples one should use, based on characteristics of the data (number of observations, etc.) and/or the variables included? I usually am able to render successfully to the c:\tmp folder, but when I came into work today, I rendered out the image on my work laptop, and everything seems to work, but I'm not getting an output to the tmp directory.  Does anyone know how to make this work? Using apt-get how to check have installed latest version ? Hello im just new for Linux   I know that  sudo apt-get   is for installing application   but how I would know that I have installed the latest version of the application   for example apt-get install sun-java6-jdk   is there an option to upgrade or see the latest version   or its ok to install an old version the application and Linux will upgrade it for me ? Do there exist an infinite number of integer-solutions $(x,y,z)$ of $x^x\cdot y^y=z^z$ where $1\lt x\le y$? Question : Do there exist an infinite number of integer-solutions $(x,y,z)$ of $x^x\cdot y^y=z^z$ where $1\lt x\le y$ ?  Motivation : After struggling to find a solution, I've just got one solution, which is  $$(x,y,z)=(1679616, 2985984, 4478976).$$  In the following, I'm going to write how I got this solution.  Letting $d$ be the greatest common divisor of $x,y,z$, we can represent $$x=ad, y=bd, z=cd$$ where $a,b,c$ are coprimes with each other. Then, we get $$d^{a+b-c}\cdot a^a\cdot b^b=c^c.$$  In the following, let's consider without the condition $x\le y$. Here, I suppose  $$a=2^m, b=3^n, a+b-c=1.$$  (As a result, this supposition works.)  Then, we get $$d=\frac{c^c}{2^{ma}\cdot 3^{nb}}.$$  Hence, letting $c=2^k\cdot 3^l$, if  $$kc\ge ma=m\cdot 2^m, lc\ge nb=n\cdot 3^n,$$ then $d$ is an integer.  Since $(m,n)=(4,2)$ satisfies the above conditions, then we get $d=2^8\cdot 3^6=186624.$ Hence we can get  $$x=9d=2^8\cdot 3^8=1679616, y=16d=2^{12}\cdot 3^6=2985984, z=24d=2^{11}\cdot 3^7=4478976.$$ Note that here I interchanged $x$ and $y$.  P.S : I was surprised to get this solution because I got this almost by chance. So, I don't know the other solutions. If you have any helpful information, please teach me.