I have installed Ubuntu 12.04. I want to install xfce desktop. When I tried to install Xubuntu desktop, I got the  following message.  sudo apt-get install xubuntu-desktop  Media change: please insert the disc labeled  'Ubuntu 12.04.1 LTS _Precise Pangolin_ - Release i386 (20120817.3)' in the drive '/cdrom/' and press enter   I didn't know why I'm getting this error, and also I don't have CD drive. I installed Ubuntu using usb.  Please let me know how to install xubuntu desktop.
I can't update 12.04 LTS. The Update Manager shows this:  CD/DVD 'Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423)' is required Please insert the above CD/DVD into the drive '/media/cdrom/' to install software packages from it.   The image I downloaded and burned to CD is from  the PC (Intel x86) desktop CD version. I burned many CDs but the result is the same.
Needing to upgrade Squid 3.5.12 on Ubuntu 16.04.3 LTS to a more recently patched version (Squid 3.5.23) I found some instructions here:   Entered the first 3 commands exactly and got a note from apt-get: "N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository ' xenial InRelease' doesn't support architecture 'i386'"  I don't have typos and nonexistent foreign architectures as others have done:  root@wprdsqd01:/# dpkg --print-foreign-architectures i386 root@wprdsqd01:/# dpkg --print-architecture amd64 root@wprdsqd01:/#   Does this just mean that the repository doesn't have i386 (32bit) binaries ?  Thanks How do I read from /proc/$pid/mem under Linux? The  tells me that /proc/$pid/mem “can be used to access the pages of a process's memory”. But a straightforward attempt to use it only gives me  $ cat /proc/$$/mem /proc/self/mem cat: /proc/3065/mem: No such process cat: /proc/self/mem: Input/output error   Why isn't cat able to print its own memory (/proc/self/mem)? And what is this strange “no such process” error when I try to print the shell's memory (/proc/$$/mem, obviously the process exists)? How can I read from /proc/$pid/mem, then? Why is rabies incurable? I'm still not sure about the mechanics that lead to rabies being incurable. I know that it can be treated before any symptoms show up, but why is it that once symptoms show the person is a dead man walking? How do I make a program auto-start every time I log in? I frequently need to start several programs that I use every time I start my computer. How can I make it so that whenever I login the program is automatically launched? Could you list all possible directories where Android apps may store data, providing description what kind of data are stored in each directory? This girl that I'm friends with and have actually seen in person before, keeps posting [on social media] that she "loves when the transfer goes through" and gets $2000-$6000 for free quite often. She said you can make up to $6500 a day. She is not very smart and barely spells correctly. She keeps saying that all she is doing is "transfers" and that's it. So many of my friends are feeding into this crap. So I asked her what it is. She basically said "it's legit" and asked me for my bank username and password so she could see how much money to deposit into my account. I said no way and left it at that. She also said she is not stealing or doing anything illegal. She is getting her friends free money and I think they're naive. What is she actually doing? Is it illegal? I am sure she is incapable of doing crazy money wiring to different countries.   Thank you everyone for answering my question. I am not stupid, I did not give her my information. I knew she was up to something illegal, so thank you for giving me some input on what exactly she is doing. I submitted an anonymous tip to my local sheriff's department. I'm hoping they see it and pursue it, or forward it to the right authorities I.e the FBI or something. What's the Best Practice reinstalling windows 7 on a dual boot with ubuntu 11.04 I've posted a question  that I have a 32bits windows 7 on a dual boot machine with ubuntu 10.04 upgraded to 11.04. From the responses I had from the questions, I decided to reinstall the windows 7 but this time a 64bits version.  I've install the grub on the first section of the HDD on which ubuntu is install, meaning the 2nd Drive.  I still want guidance before I proceed.  What would you suggest me as best way to achieve that without disturbing the boot loading.  thank you for reading this. We have 10 PC with some version of Ubuntu and only remote access. While doing some upgrades to custom software I did not notice that the line endings in some scripts were Windows version (CR+LF) and not the Unix version (LF). So now when I want to launch the script it gives an error:   bash: /usr/local/bin/portsee: /usr/bin/python^M: bad interpreter: No such file or directory   Is there a way to change all line endings in a script from terminal. The thing is that I can not install any new software to this group of PC-s. Installing Cygwin packages from the command-line Integral of $\sin x \cos x$ using two methods differs by a constant? $$ \int \sin \theta\cos \theta~d \theta= \int \frac {1} 2  \sin 2\theta~ d \theta=-\frac {1} 4  \cos 2\theta$$ But, if I let  $$ u=\sin \theta , \text{ then }du=\cos \theta~d\theta $$ Then $$ \int \sin \theta\cos \theta~d \theta= \int u ~ du =\frac { u^2 } 2 =\frac {1} 2 \sin^2 \theta $$ Since $$ \sin^2 \theta =\frac {1} 2 - \frac {1} 2 \cos 2\theta$$ The above can be written as $$ \int \sin \theta\cos \theta~d \theta= \frac {1} 2 \sin^2 \theta =\frac {1} 2 \left( \frac {1} 2 - \frac {1} 2 \cos 2\theta \right)=\frac {1} 4-\frac {1} 4 \cos 2\theta   $$ Why are the two results differ by the constant $1/4$? Thank you. How do I properly clean up Excel interop objects? I'm using the Excel interop in C# (ApplicationClass) and have placed the following code in my finally clause:  while (System.Runtime.InteropServices.Marshal.ReleaseComObject(excelSheet) != 0) { } excelSheet = null; GC.Collect(); GC.WaitForPendingFinalizers();   Although this kind of works, the Excel.exe process is still in the background even after I close Excel. It is only released once my application is manually closed.  What am I doing wrong, or is there an alternative to ensure interop objects are properly disposed of? Is it possible to write a regular expression that matches a nested pattern that occurs an unknown number of times? For example, can a regular expression match an opening and closing brace when there are an unknown number of open/close braces nested within the outer braces?  For example:  public MyMethod() {   if (test)   {     // More { }   }    // More { } } // End   Should match:  {   if (test)   {     // More { }   }    // More { } } A locally constant sheaf on a locally connected space is a covering space; Proof? As part of my hobby i'm learning about sheaves from Mac Lane and Moerdijk. I have a problem with Ch 2 Q 5, to the extent that i don't believe the claim to be proven is actually true, currently. Here is the question repeated:     A sheaf on a locally connected space $X$ is locally constant if each point $x \in X$ has a basis of open neighborhoods  $\mathcal{N}_x$ such that whenever $U,V \in \mathcal{N}_x$ with $U \subset V$, the restriction $\mathcal{F}V \rightarrow \mathcal{F}U$ is a bijection. Prove that $\mathcal{F}$ is locally constant iff the associated etale space over $X$ is a covering.   I don't have a problem (i think) showing the "covering" $\rightarrow$ "locally constant" direction of the implication. My problem is in the reverse direction. In fact, in the process of trying to solve this problem i think i have come up with a very simple counterexample.  Here's my attempt at a counterexample:  Let $X = \{a,b,c\}$ be  finite space with open subsets $\{\{\},\{a\},\{a,b\},\{a,b,c\}\}$. I claim this is hyper-connected and locally connected.  Let $\mathcal{F}$ be the sheaf with $\mathcal{F}(\{a,b,c\}) = \{q\}$, $\mathcal{F}(\{a,b\}) = \{r,s\}$, and $\mathcal{F}(\{a\}) = \{t\}$, where $r = q|_{\{a,b\}}$, and $t = q|_{\{a\}} = r|_{\{a\}} = s|_{\{a\}}$. I claim this defines a locally constant sheaf. Indeed we can have $\mathcal{N}_{a} = \{\{a\}\}$, $\mathcal{N}_{b} = \{\{a,b\}\}$, and $\mathcal{N}_c = \{\{a,b,c\}\}$.  Now we can calculate the corresponding etale space $p : E \rightarrow X$ as follows: $E = \{\dot{q}(a), \dot{q}(b), \dot{q}(c), \dot{s}(b)\}$, and has these four distinct elements since $\dot{q}(a) = \dot{r}(a) = \dot{s}(a) = \dot{t}(a)$, and $\dot{q}(b) = \dot{r}(b)$. The action of $p$ follows by construction.  However, $p$ does not appear to me to be a covering space. In particular, the only neighborhoods of $b \in X$ are $\{a,b\}$and $\{a,b,c\}$ and we have $p^{-1}(\{a,b\}) = \{\dot{q}(a),\dot{q}(b),\dot{s}(b)\}$ and this cannot be partitioned into homeomorphic images of $\{a,b\}$ because $2 \nmid 3$. Similarly, $p^{-1}(\{a,b,c\}) = \{\dot{q}(a), \dot{q}(b), \dot{q}(c), \dot{s}(b)\}$ and this cannot be partitioned into homeomorphic images of $\{a,b,c\}$ since $3 \nmid 4$.  So i think i have a locally constant sheaf on a locally connected space whose corresponding etale space is not a covering. What have i done wrong? I have seen the claim mentioned elsewhere so i'm convinced i'm wrong somewhere. Perhaps someone knows where a correct proof is published otherwise? I want to do:  cat update_via_sed.sh | sed 's/old_name/new_name/' &gt; new_update_via_sed.sh   in my program.  But I want to use variables, e.g.  old_run='old_name_952' new_run='old_name_953'   I have tried using them but the substitution doesn't happen (no error). I have tried:  cat update_via_sed.sh | sed 's/old_run/new_run/' cat update_via_sed.sh | sed 's/$old_run/$new_run/' cat update_via_sed.sh | sed 's/${old_run}/${new_run}/' I'm currently unable to access anything via the Stack Exchange app under iOS; is this a known issue? How to uncompress separated tgz files? I am receiving this error message when I'm trying to uncompress a .tgz archive:  $ tar -zxvf OVM_EL5U3_X86_EBIZ12.1.1_DB_VIS_PVM.tgz.1 gzip: stdin: not in gzip format tar: Child returned status 1 tar: Error is not recoverable: exiting now   As you can see, the file name ends with .tgz.1.  When the file name is .tgz.0 it will be uncompressed with no error by the tar -zxvf command. Local DNS server Where is the usage of Ubuntu cloud guest image on OpenStack documented? With markdown, you can use some dashes for headings. For example, this: Hello ---- this is some other text  renders as this: Hello this is some other text This is fine and works well. When I want to quote that text is when the problem arises, since this Markdown: &gt; Hello &gt; ---- &gt; this is some other text  When written down shows well in the preview but not when posted:  Hello this is some other text   As an example, see an screenshot of the preview:    and a screenshot of the posted content, where the ---- becomes a &lt;hr&gt;:  Note a similar bug I also reported: . How to change default viewport shading in 2.8? Is it possible to change the default mesh color/shading in 2.8 to be more like 2.79? I'm finding it hard to see finer detail in 2.8. On the left is 2.8 and the right is 2.79