I chowned -R username /usr/lib and now i cannot sudo or do any thing really due to sudoers.so belonging to username.  How do i fix this and make /usr/lib owned by root again?
Recently I had to change the folder permissions of /usr folder. Now the whole sudo is not working. If I try to update my system using this command:  sudo apt-get update   I get the following message:  sudo: /usr/lib/sudo/sudoers.so must be only be writable by owner sudo: fatal error, unable to load plugins   So I tried to change the folder permissions by opening Nautilus as root by using this command  gksudo nautilus   But nothing happened. Nautilus didn't open. This is an emergency as the whole of sudo is not working. when I tried searching the solution from Google many suggested re-installation. I don't prefer re-installation. so is there any other solution?
List the files accessed by a program In Python, how do I determine if an object is iterable? Show that $R/I\otimes_R R/J\cong R/(I+J)$ Let $R$ be a commutative ring with identity and $I$ and $J$ be ideals in $R$.     Show that $R/I\otimes_R R/J\cong R/(I+J)$ as $R$-modules.   This is what I tried.  Define a map $f:R/I\times R/J\to R/(I+J)$ as $f(\bar r, \bar s)=rs+(I+J)$. This is a well-defined bilinear map.  By the universal property of tensor products, we get an $R$-linear map $F:R/I\otimes_R R/J\to R/(I+J)$ which sends $\bar r\otimes \bar s$ to $rs+(I+J)$.  This map is surjective.  So all we need to show is that the kernel of $F$ is $0$.  But I am unable to do this. How to set edge bevel weights from a python script I need to set weights for some edges from a python script. I have tried looping through object.data.edges and setting bevel_weight values but I can't get it right. It only works if I have first edited some edge's bevel weight by hand from the 3d-view's transform window. But I would like to get it work from my script without any manual hacking.  Steps to reproduce:  Start Blender with default cube and switch to Scripting view.  Try to set weights for all edges:  for edge in C.object.data.edges:     edge.bevel_weight = 1.0   Verify that values changed:  for edge in C.object.data.edges:     edge.bevel_weight   Switch into edit mode in 3d-view and open up transform window by pressing n. Select edges to see that the change did not work (bevel weights are all zero). Switch back to object mode and read values again in scripting console to see that they were reset to zero:  for edge in C.object.data.edges:     edge.bevel_weight   Go back to edit mode and change some edge bevel weight straight from the transform window by hand. Go back to object mode and change values again from the scripting console:  for edge in C.object.data.edges:     edge.bevel_weight = 1.0   This time it works, bevel weights are 1.0 when you go back to edit mode and look from the transform window.   Any ideas? My final need is to apply a bevel modifier to only some set of edges and that's why I'm trying to mark them by using weights. Using vertex group for bevel modifier does not work in my situation, since I need to specify edges, not vertices, which to bevel.   I'm using Blender v2.71. Once a world enters hardmode, corruption and hallows being spreading at an alarming rate, including the underground. Grass, which grows on dirt, succumbs easily to both. Jungles and glowing mushrooms grow on mud and provide unique and valuable items. Will corruption/hallows destroy these if left unchecked? If they do destroy mud-based life, how can I preserve these fragile ecosystems? A man enters a comatose author's dreams to wake him up D+ and D- on USB I'm making a small project which will take +5v from USB, What should I do with the D+ and D-, keep it open or short them to ground or do I have to add some components?  I want to run ATMEGA168 and 16x2 LCD with back light. Imagine that a PC gets reduced to 0 hit points during a battle. The battle continues for a couple more rounds and they roll their death saves, one success and one failure (not sure if this part of the question is relevant).  Then the rest of the party defeats the last enemy and battle is over. Now what?    Does the downed PC keep rolling death saves until they strike 3 one way or the other? Does everyone else repeatedly roll for Medicine to stabalise the dying PC? Or (as we've been ruling it) they are just assumed to become stabilised because combat is over (I'm fairly certain this probably isn't RAW or RAI though).   I've looked through the PHB and I've only managed to find descriptions of being stabilised during combat, not after it.  Ideally I'd like a rule quoted (or a tweet or something) to point to where such a thing is outlined in the rules, if it is written anywhere. How to reset postgres' primary key sequence when it falls out of sync? I ran into the problem that my primary key sequence is not in sync with my table rows.   That is, when I insert a new row I get a duplicate key error because the sequence implied in the serial datatype returns a number that already exists.  It seems to be caused by import/restores not maintaining the sequence properly. I need to show that for prime numbers of the form $p=4n+1$, $x=(2n)!$ solves the congruence $x^2 \equiv-1\pmod p$. I then need to show this implies p isn't a gaussian prime.   I have started to solve this using Wilson's theorem that a number $z$ is prime iff $(z-1)!\equiv-1\pmod z$. Therefore the endpoint of my proof should be that $(p-1)!\equiv-1\pmod p$.  As $p$ is of the form $p=4n+1$, I only need to prove that $4n!$ is congruent to $-1$ modulo $p$.   Here is my working so far: Starting with the congruence $x^2 \equiv -1\pmod p$:    $$\eqalign{x^2 = -1\pmod p&amp;\implies   x^2 + 1 = kp \implies (x-i)(x+i) = kp\cr &amp;\implies ((2n)!-i)((2n!)+i))=kp \implies 4n!- 1 =kp\cr}$$   This is where I start to run out of any ideas that seem to get me anywhere. Any tips would be greatly appreciated! Kolmogorov-Smirnov two-sample $p$-values I am using the Kolmogorov&ndash;Smirnov two-sample test to compare distributions, and I noticed a $p$-value is frequently reported as the test statistic. How is this $p$-value determined? I know it's the probability of obtaining a result at least as large as the one obtained, but how is this $p$-value determined given this is a nonparametric test? That is, we can't assume Gaussian fluctuations in the distribution and compute the $p$-value using a $t$-test.  Thanks! What does the $\ni$ (backwards element of) symbol mean?  It doesn't appear in the , and a Google search for "backwards element of" or "backwards epsilon" turns up contradictory (or unreliable) information.  It seems it can mean both "such that", or "contains as an element".  Is this correct, and if so, which is the more common usage? What is the best way to convert seconds into (Hour:Minutes:Seconds:Milliseconds) time? How do you carry a dog on a bike? Over the years I have seen a few people transport a dog on a bike.  What options have you seen?   Please include a photo in your answer if possible. Why is channel capacity a factor of bandwidth instead of frequency? I'm trying to understand the concept of capacity for a wireless channel.  Some help would be appreciated.  For a AWGN channel capacity is calculated as:  $$C=B \cdot log_2(1 + S/N)\text{ bits/sec}$$  B = bandwidth.  This is what I don't understand.  Why isn't it a factor of frequency? To me considering bandwidth only makes sense in cases where the system changes frequency.   Bandwidth is the difference between an upper and lower frequency range.  Well, what if I'm using a fixed-frequency signal?  Fupper and Flower would be the same value, right?  So does that mean B=0?  So a fixed frequency signal can't carry any data?  We know that's not true, AM radio does it.  So what am I missing? According to this formula, a fixed-frequency signal would have the same performance regardless of whether it's at high or low frequency.  This makes no sense to me.  For example say my bandwidth is 1Hz at a fixed frequency of 1Hz.  Compare this with a bandwidth of 1Hz at a frequency of 2.4GHz.  It's plainly obvious that I can cram way more bits into 2.4 x 109 cycles/second than I can with just 1/sec.  But according to this formula I can't.  Please help. What about fractional differences?  Waveforms are analog in nature, so we could have a 1Hz signal and a 1.5Hz signal.  Likewise at the high frequency range.  Say 2.4GHz minus 0.5Hz.  There is an infinite amount of space between 1 and 1.5.  Could not 1Hz and 1.001Hz serve as two separate channels?  In terms of practicality I realize this would be difficult, nearly impossible to measure this difference with modern electronics, especially with noise added, but in pure theory you could have two channels.  So in that sense, shouldn't there be an infinite amount of bandwidth between two frequencies?  Or do we only count in 1Hz whole number increments? Did this character even qualify for being Azor Ahai or The One Who Was Promised? In the books and to some degree in the show as well there is a prophesy about the legendary figure Azor Ahai. But in the latest Game of Thrones episode (S08E03) we see Arya      killing the Night King.   However in a  we discussed​ all possible candidates but nobody thought about Arya. Does she even fulfill the prophecy? If she does, how? I have an HP laptop with with a Core-i5 450m processor and an ATI Radeon 5650 1GB graphics card. When I played crysis warhead on my system its temprature went up to 82° c. Is it safe to play games up to this temperature level? How do I find the files installed by a particular package? Where is the .deb file to look at? I have installed pulseaudio-module-bluetooth using apt.  $ type pulseaudio-module-bluetooth bash: type: pulseaudio-module-bluetooth: not found $ which pulseaudio-module-bluetooth $ whereis pulseaudio-module-bluetooth pulseaudio-module-bluetooth:   Clearly, I'm looking for the wrong thing.  The package does not simply install a command that is the same name as the package.  Alright, then.  I want to find out what all commands (or executables) this package installed, and their locations.  The answers to "" tell me how to find the files installed by the package if I have a .deb file.  I'm not installing directly from a .deb file, though.  I'm using apt.  Where is the .deb file that that used?  Is there a copy on my system somewhere that I can query with the commands in the answers to that question?  Where?  If there isn't a local copy on my system, can I get one with apt?  How?  Is there some handy apt (or similar) command that wraps this up for me, so that I do not have to run dpkg-deb directly?  What is it?  Can I find the package's file list entirely on-line, without explicitly downloading any .deb files and before installing anything with apt?  How? Most of the recipes I'm using (mainly Modernist; stocks, caramelized vegetables, confit) suggest cooking at 15psi. My pressure cooker has two settings 12psi and 7psi. I've always had success just using 12psi in recipes where it says 15psi. However recently the 12psi mode has broken on my PC. I can now only cook at 7psi. How can I convert my recipes to use this lower pressure?  For example I would cook a chicken stock at 12psi for 90mins, I presume at 7psi the cooking time would need to be longer but by how much? Combining |- and !.5! in TikZ How do I combine the !.5! operator with the -| operator?  I want a node that has x-coordinate equal to the average of x coordinates of nodes A and B, and a y-coordinate equal to the average the y coordinates of nodes C and D.