So I recently reinstalled ubuntu on a computer at work and now I am setting up the secondary internal HDD. I followed the directions  for mounting the drive (the drives was already formatted into two partitions and had data on them so I only had to mount them). Everything went fine, except for permissions on the drives. I followed the instructions of changing the group of the drive to plugdev and the chmod lines below that. Myself and the only other user currently on the computer are both in the plugdev group. But I still have to use sudo to do a lot of things on the drive (was compiling q-chem earlier and had to sudo all of the commands that I normally wouldn't).  I'd like to get this figured out, and to make sure that any time a new user is added to the computer that they will automatically be given permissions for the drive. I know I can probably just chown the drive, but I am not sure if multiple users can own the drive at the same time, and I don't want to have to do that every time a new user is created. Thanks in advance for any help.
I have two users, user1 and user2, that are both members of groupA. user2 has a folder in their home directory called folderA. If they wish to allow read-write-execute permissions for all members of groupA, how would they do this?  What if folderA contains many files and additional folders that also need to have read-write-execute permission?  Information regarding groups is a little 'spotty' across the web, so I am putting my question here in the hope someone posts a clear answer that might help others out too.  Thanks!
Today, when looking up the definitions of the phrasal verb "take sth up", I noticed that one of them was written like this: "to start or begin something such as a job." For the first time I realised that probably "start" and "begin" don't exactly mean the same thing.So the question is what the difference is between the two, and if there are cases when they mean exactly the same thing. I'm studying measure theory and two question came to my mind:        If $f:\mathbb{R}\to\mathbb{R}$ is monotone and $B\subseteq\mathbb{R}$ is borel, is the image $f(B)$ borel?   If $f:\mathbb{R}\to\mathbb{R}$ is a monotone function (say, non-decreasing), does there exist a sequence of continuous functions $f_n:\mathbb{R}\to\mathbb{R}$ converging pointwise to $f$?      Here's the motivation for those questions: Let $(X,M)$ and $(Y,N)$ be measure spaces.   It's known that if $\mu$ is a measure on $(X,M)$ and $f:X\to Y$ is measure, then we have the pushforward measure $f_*\mu(A)=\mu(f^{-1}(A))$ on $(Y,N)$. What if we were to define a "pullback measure"? Given a function $f:X\to Y$ such that $f(M)\subseteq N$ (i.e. $f$ maps measurable sets to measurable sets) and a measure $\nu$ on $N$, the natural formula would be $f^*\nu(A)=\nu(f(A))$. So we ask if is there a good amount of functions which map measurable sets to measurable sets in $\mathbb{R}$, and monotone functions seem like good candidates (for strictly monotone, continuous functions, the result is valid and there are several answers on the web). If this were true, maybe we could use some convergence argument to solve the problem above. Accessing bash command line args $@ vs $* how can i show site logo, name and slogan Separately in custom area in my site theme, I now use this code to display theme, buts this code don't allow me to edit each of them Separately.  {{ page.header }} Can a warlock use one of their Thirsting Blade attacks to grapple or shove? TikZ: Intersection of two lines what is the easiest way to determine the intersection of two lines? I tried  \usetikzlibrary{intersections} \begin{tikzpicture}[every node/.style={black,above right}] \draw[name path=line 1] (0,0) -- (2,2); \draw[name path=line 2] (2,0) -- (0,2); \fill[red,name intersections={of=line 1 and line 2}]     (intersection-1) circle (2pt) node {1}     (intersection-2) circle (2pt) node {2} \end{tikzpicture} Is there a power saving application similar to Jupiter? I downloaded Ubuntu 14.04 (64 bit) lts. I made a bootable usb stick. But I keep receiving this error message upon booting:  SYSLINUX 4.04 EDD 20110518 Copyright (C) 1994-2011 H. Peter Anvin et al Unknown keyword in configuration file: gfxboot.c32: not a COM32R image Reprojecting MODIS-Sphere ESRI GRID file to WGS84 using QGIS/GDAL I have an ESRI GRID file projected in MODIS-Sphere (here's the dataset ) that I need to convert to a WGS84 GeoTIFF.  I tried Raster > Projections > Warp (Reproject) and got this nonsense:   I then thought I'd use the MODIS reprojection tool or HEG to convert it, but they only accept HDF files and using QGIS' warp or translate functions to convert this file to HDF throwns an error. This guy was trying to do the same thing in Arc, no joy:   I looked for clues in the metadata, and the file seems a little goofy; gdalinfo yields:  Driver: AIG/Arc/Info Binary Grid Files: seto_uf        seto_uf.aux        seto_uf/.aux.xml        seto_uf/.DS_Store        seto_uf/dblbnd.adf        seto_uf/hdr.adf        seto_uf/log        seto_uf/metadata.xml        seto_uf/sta.adf        seto_uf/vat.adf        seto_uf/w001001.adf        seto_uf/w001001.tif        seto_uf/w001001.tif.aux.xml        seto_uf/w001001x.adf Size is 7468, 2911 Coordinate System is `' Origin = (-17345341.010356999933720,8423784.764957003295422) Pixel Size = (5000.000000000000000,-5000.000000000000000) Corner Coordinates: Upper Left  (-17345341.010, 8423784.765)  Lower Left  (-17345341.010,-6131215.235)  Upper Right (19994658.990, 8423784.765)  Lower Right (19994658.990,-6131215.235)  Center      ( 1324658.990, 1146284.765)  Band 1 Block=256x4 Type=Byte, ColorInterp=Undefined   Description = Seto_UF   Min=0.000 Max=101.000    NoData Value=255   So it can't determine the coordinate system.  There's a .tif included in the directory, but gdalinfo on that shows:  Driver: GTiff/GeoTIFF Files: w001001.tif        w001001.tif.aux.xml Size is 7468, 2911 Coordinate System is: GEOGCS["Unspecified datum based upon the GRS 1980 Authalic Sphere",     DATUM["unknown",         SPHEROID["unnamed",6371007,1]],     PRIMEM["Greenwich",0],     UNIT["degree",0.0174532925199433],     AUTHORITY["EPSG","4047"]] Origin = (-17345341.010356999933720,8423784.764957003295422) Pixel Size = (5000.000000000000000,-5000.000000000000000) Metadata:   AREA_OR_POINT=Area Image Structure Metadata:   INTERLEAVE=BAND Corner Coordinates: Upper Left  (-17345341.010, 8423784.765)  Lower Left  (-17345341.010,-6131215.235)  Upper Right (19994658.990, 8423784.765)  Lower Right (19994658.990,-6131215.235)  Center      ( 1324658.990, 1146284.765)    So it says the units are degrees but those huge corner coordinates and origin values don't agree.  Any ideas?  My setup: OSX 10.9.4 QGIS 2.6.1 Brighton GDAL 1.11.2 (apparently there are newer versions but this is the latest you can get on OSX without having to compile it yourself) Ubuntu 14.04.5/16.04 and newer on AMD graphics \pdfendlink ended up in different nesting level than \pdfstartlink Can't update drupal core to 7.27 It appears that on Server Fault and Super User, the navigation bar and question title have suddenly become misplaced. The same does not occur on SO and mSO, nor on any of the other SE sites I spot-checked.  This is being seen in both Chrome and Firefox and just began occurring within the last few minutes.      What it should look like:      While this was fixed for a few hours, it has returned as of 22:05. Delimiter is being changed with fields I have a file with values organized in columns, and separated by commas, as in the file below:   324,01,1,113333600000,1,, 016,01,1,134954200000,1,, 770,01,1,109069200000,1,, 853,01,1,111518800000,1,,   When I use the following awk command, the delimiter is being changed from commas to spaces   Code:  awk -F, '{$4=$4/1024}{print $0}'   The output becomes:   324 01 1 110677343.75 1   016 01 1 131791210.93 1   770 01 1 106512890.62 1   853 01 1 108905078.12 1    How can I change the value of the field without changing the delimiter? I'm loading an XML document in my C# application with the following:  XDocument xd1 = new XDocument(); xd1 = XDocument.Load(myfile);   but before that, I do test to make sure the file exists with:  File.Exists(myfile);   But... is there an (easy) way to test the file before the XDocument.Load() to make sure it's a valid XML file?  In other words, my user can accidentally click on a different file in the file browser and trying to load, say, a .php file causes an exception.    The only way I can think of is to load it into a StreamWriter and simple do a text search on the first few characters to make sure they say "  Thanks!  -Adeena Install suspension forks on non-suspension bike I have a 1990s Saracen PowerTrax. Is there a way I can install a suspension fork, or will that muck up the bike somehow? I'm actually interested in ways to raise the bars with respect to the seat, so that wouldn't be a problem. My toes rubbing in the wheel, in the other hand, would definitely be a problem. Is there a simple way to change the thickness of a curved tube without scaling its overall size? E.g. scaling the minor radius of an already created torus without affecting its major radius or change the bevel width of a curve that has already been converted to a mesh. I was wondering if it's possible to run an Ubuntu virtual machine using VirtualBox in background, I mean, without any window open.  The idea is to connect via SSH to the Linux host, that would be running in background.  Has anyone ever done something like this? Is it possible? I am always really hesitant to mess around with $IFS because it's clobbering a global.   But often it makes loading strings into a bash array nice and concise, and for bash scripting, conciseness is hard to come by.   So I figure it might be better than nothing if I try to "save" the starting contents of $IFS to another variable and then restore it immediately after i am done using $IFS for something.   Is this practical? Or is it essentially pointless and I should just directly set IFS back to whatever it needs to be for its subsequent uses? My USB drive used to be originally 8GB when I bought it.  I'm trying to reformatted in Windows 7 by right clicking on the drive and selecting Format.... But the capacity only shows 250MB.  Is there something I can do to get the original size back? Maybe it got partitioned in a weird way?   The  flash drive is a SanDisk Cruzer Micro 8GB. I got it from Wal-Mart but this is the same drive.