How can I use sed to delete lines two (or any number) after a match but not including the match and lines in between?  For example:  Enter command below &gt; login Command valid Enter your password at the below prompt Remember to make sure no-one is looking at your screen &gt; mysecretword Password accepted   I want to only delete the line "> mysecretword" on account of it being two lines after the line "Enter your password at the below prompt". I can't use absolute line number positions, because the match could appear any number of lines after the start of the file.  Searching online I find a lot of solutions like sed '/Enter your password.*/,+3d' filex, but this would also remove the "Enter your password..." line and the following line, which is not what I want. I only want to remove one line, which is a certain number of lines after a match.  How can I do this with sed (or indeed any other commonly-available tool)?
I have a question related to deletion of strings that appear at the n+2 position after the matched string which is at position n using awk for multiple files. I am able to print it using the command:   awk -F '/radius-server/{nr[NR+4]}; NR in nr' *   Where the matched string is radius-server.  Since I'm not too familiar with  awk I would appreciate it if someone could help me  delete this line in place , that would mean that I want the files to be modified and saved after the deletion is done.  An example scenario is below - file 1 which is unmodified    radius-server dz7HQQH4EqT5 1645-1646  !  oj5icqh1dGpSK  !    alias exec t telnet  alias exec sis show interface status  !   file 2, after modification is -  radius-server dz7HQQH4EqT5 1645-1646 ! ! alias exec t telnet alias exec sis show interface status !   I understand that I can do a pattern matching method using sed -i '/pattern/d' to remove it but that is not what I want as the values change from file to file. Any help would be much appreciated.
Proof of continuity of Thomae Function at irrationals. At what age does a toddler stop being a toddler? Windows 8 turns program sound volume down randomly I recently upgraded to Windows 8 from Win 7 64 bit and have started to encounter a strange issue. When I have any program running which plays sound, such as a game or spotify, after a random interval (usually around 5-10 minutes) the program sound will set itself really low.    If I Alt-Tab to the desktop and check the Mixer I can see that the Application volume has automatically set itself really low - the other volume levels (i.e. the Device speakers) stay the same.  I'm able to just set the application volume back to a reasonable level and it stays that way for another 5 - 10 minutes then goes quiet again.  My sound is Realtek High Definition Audio and my machine is an Acer Aspire 5738G if that helps in any way.  Any help much appreciated! Recently, I read in the journal  that Stephen Hawking wrote a paper claiming that black holes do not exist.  How is this possible? Please explain it to me because I didn't understand what he said.  References:   Article in Nature News:  (Zeeya Merali, January 24, 2014). S. Hawking, Information Preservation and Weather Forecasting for Black Holes, . How do I get a file extension in PHP? This is a question you can read everywhere on the web with various answers:  $ext = end(explode('.', $filename)); $ext = substr(strrchr($filename, '.'), 1); $ext = substr($filename, strrpos($filename, '.') + 1); $ext = preg_replace('/^.*\.([^.]+)$/D', '$1', $filename);  $exts = split("[/\\.]", $filename); $n    = count($exts)-1; $ext  = $exts[$n];   etc.  However, there is always "the best way" and it should be on Stack Overflow. integral roots for $f(x) = 41$ if $f(x) = 37$ has 5 distinct integral roots. How to upgrade to MySQL 8.0? I have a Drupal site 8.6.10 on an Ubuntu server 18.04 with MySQL 5.7.25  I want to update MySQL to version 8.0  Here are the steps I followed :   I backed up my database. I uninstalled MySQL from my server with the commands :  $ sudo systemctl stop mysql $ sudo apt remove mysql-* $ sudo apt purge mysql-* $ sudo apt autoremove $ sudo dpkg -l | grep mysql | grep ii  I added the repository with the command :  $ wget https://repo.mysql.com//mysql-apt-config_0.8.12-1_all.deb  I installed the package with the command :  $ sudo dpkg -i mysql-apt-config_0.8.12-1_all.deb            My problem :   I install MySQL with the command :  $ sudo apt update $ sudo apt install mysql-server    When I do step 5, it installs MySQL 5.7 why does not it install version 8 ? ls: cannot access .gvfs: Permission denied Whenever I run an application in terminal as root (such as sudo gedit  /etc/default/varnish) , subsequently when I open another terminal I get "ls: cannot access .gvfs: Permission denied" error at top line of terminal.   I found a solution on the net     umount /path/to/.gvfs   rm -rf .gvfs   but it only fixes problem temporarily.  It appears that I have two mounted instances of gvfs in my system    $ sudo mount |grep gvfs     gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=33)     gvfsd-fuse on /home/****/.gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=0,group_id=0)   I don't know if it's related to, a few months ago I had to change permission in my home folder like     sudo chown -R $USER:www-data   Would you please help me fix it?  EDIT: After I unmount /run/user/1000/gvfs I don't get that error. Is there a way to forget node names between TikZ pictures? I have a document with several TikZ pictures in it.  I generally use simple names for the nodes such as:  \node (A) at .....  \node (B) at .....   and so forth.  Because of this I have name clashes between the various pictures.  That's generally not a problem.  However I find myself in a position where I may or may not have defined a certain node within a given picture.  So I use the following snippet to test whether the node has been defined:  \makeatletter \long\def\ifnodedefined#1#2#3{%%   \@ifundefined{pgf@sh@ns@#1}{#3}{#2}} \makeatother   Unfortunately this fails if I've already created a node by the same name in another picture.  Is there a way to scope the definitions of nodes or is there a way to undefine nodes once you no longer need them?  P.S.  I'm aware that I could embed each picture in a standalone file and import it using \includegraphics.  Unfortunately, this approach will not work for the document I'm creating.  MWE  \documentclass{article} \usepackage{tikz} \usetikzlibrary{calc}  \makeatletter \long\def\ifnodedefined#1#2#3{%%   \@ifundefined{pgf@sh@ns@#1}{#3}{#2}} \makeatother  \setlength{\parindent}{0pt} \pagestyle{empty} \begin{document}   There's no node \textbf{D} here, so I draw a triangle:\par \begin{tikzpicture}    \coordinate (A) at (0,0);   \coordinate (B) at (1,0);   \coordinate (C) at (1,1); %  \coordinate (D) at (0,1);    \ifnodedefined{D}     {  \draw (A) foreach \myn in {B,C,D} {  -- (\myn) } --cycle;  }     {  \draw (A) foreach \myn in {B,C}   {  -- (\myn) } --cycle;  }  \end{tikzpicture}     There is a node \textbf{D} here, so I draw a square:\par \begin{tikzpicture}    \coordinate (A) at (0,0);   \coordinate (B) at (1,0);   \coordinate (C) at (1,1);   \coordinate (D) at (0,1);    \ifnodedefined{D}     {  \draw (A) foreach \myn in {B,C,D} {  -- (\myn) } --cycle;  }     {  \draw (A) foreach \myn in {B,C}   {  -- (\myn) } --cycle;  }  \end{tikzpicture}      There isn't supposed to be a node \textbf{D} here.  I'm expecting a triangle, but get a square.\par \begin{tikzpicture}    \coordinate (A) at (0,0);   \coordinate (B) at (1,0);   \coordinate (C) at (1,1); %  \coordinate (D) at (0,1);    \ifnodedefined{D}     {  \draw (A) foreach \myn in {B,C,D} {  -- (\myn) } --cycle;  }     {  \draw (A) foreach \myn in {B,C}   {  -- (\myn) } --cycle;  }  \end{tikzpicture}  \end{document}   produces: folder content doesn't get refreshed automatically in ubuntu 14.04 I'm using Ubuntu 14.04 and when I'm doing experiments which creates new files inside a particular folder X. But I can't see these new files inside X without refreshing X.  I have increased the count to 1M in  /proc/sys/fs/inotify/max_user_watches   but still the issue is not fixed.   How to fix it?  EDIT As suggested, output of cat /etc/xdg/autostart/user-dirs-update-gtk.desktop  [Desktop Entry] Encoding=UTF-8 Exec=xdg-user-dirs-gtk-update Name=User folders update Comment=Update common folders names to match current locale Terminal=false OnlyShowIn=GNOME;LXDE;Unity; Type=Application StartupNotify=false X-KDE-autostart-after=panel NoDisplay=true X-Ubuntu-Gettext-Domain=xdg-user-dirs-gtk I use HD Tune to measure performance of the hard drive.  The tests typically take 2-3 minutes and the transfer rate of a regular hard drive decreases dramatically as the test comes to a close.    However, the SSD drive performance stays the same over (pic below) the life of the test.  This happens on all my computers.  Why is that? What is causing different spacing between a header and content on one page only? I have found that for only one page (so far) the spacing between the header and content is different from the spacing on all the other pages. You can see this behavior in the images below (from pages 2 and 3 of the document):     My .tex file contents are shown below.  \documentclass[a4paper]{report} \usepackage{fullpage} \usepackage{lipsum} \usepackage{fancyhdr} \pagestyle{fancy} \setlength{\headsep}{0.5cm}  \begin{document} \renewcommand{\headrulewidth}{0.4pt} \renewcommand{\chaptermark}[1]{\markboth{\thechapter. #1}{}} \fancyhead[L]{\bfseries \leftmark} \fancyhead[R]{\bfseries \rightmark}  \chapter{Version Control} \lipsum \lipsum \lipsum \lipsum  \end{document} Why can Naruto still use Rasenshuriken? Why is compactness in logic called compactness? In logic, a semantics is said to be compact iff if every finite subset of a set of sentences has a model, then so to does the entire set.   Most logic texts either don't explain the terminology, or allude to the topological property of compactness. I see an analogy as, given a topological space X and a subset of it S, S is compact iff for every open cover of S, there is a finite subcover of S. But, it doesn't seem strong enough to justify the terminology.   Is there more to the choice of the terminology in logic than this analogy? I am not asking for a solution to speed it up, i simply want to know how long it should take!  I would also like a way to speed it up but not something technical, im new to Blender! Proof for triangle inequality for vectors Generally,the length of the sum of two vectors is not equal to the sum of their lengths. To see this consider the vectors $u$ and $v$ as shown below.  By considering $u$ and $v$ as two sides of a triangle, we can see that the lengths of the third side is $\| u + v \|$ and we have $\| u + v \| \leq \|u\| + \|v\|$.  Under what circumstance equality occurs and how can one prove that? Mis-aligned shapefiles in QGIS? Prove that a group is infinite and nonabelian. I'm trying to solve a question of Hungerford's Algebra:     Show that the group defined by generators $a,b$ and relations   $a^2=b^3=e$ is infinite and nonabelian.   I guess a good approach would be to find an infinite and nonabelian group with two generators satisfying the same conditions and let Van Dyck do all the work. I've been thinking about the group of permutations $S_{\mathbb N}$, some groups of matrices, but I couldn't get it. Could anyone give me a hint? Thanks in advance! Power failure during upgrade During upgrade from 12.04 to 12.10 there was a power failure.  computer boots to desktop but without tools and menus to navigate.  files that can be open cannot be closed.  sidebar menu does not exist.  there is no function of the DVD drive, the USB drive nor the internet.  Possible to open GRUB but I am not familiar with it's function.  Please help. UFW Allows 22 for IPv4 and IPv6 but SSH Disconnects When Enabling sudo ufw disable followed by sudo ufw enable kicks me out of SSH  DMESG reports  [UFW BLOCK] IN=eth0 OUT= MAC=30:........ SRC=192.168.1.me DST=192.168.1.server LEN=52 TOS=0x00 PREC=0x00 TTL=128 ID=15776 DF PROTO=TCP SPT=55640 DPT=22 WINDOW=253 RES=0x00 ACK URGP=0  I can log back in without having to change rules via the console (UFW still enabled).  This started after upgrading Xenial (16.04) from kernel 4.4 to 4.15 (HWE). Upgrading to 18.04.1 did not solve the issue.  Versions:   iptables v1.6.1 ufw 0.35 4.15.0-29-generic #31-Ubuntu Ubuntu 18.04.1 LTS   UFW status verbose is (some rules were omitted, but they are all ALLOW)  Logging: on (low) Default: deny (incoming), allow (outgoing), disabled (routed) New profiles: skip  To                         Action      From --                         ------      ---- 22                         ALLOW IN    Anywhere 22 (v6)                    ALLOW IN    Anywhere (v6)   Why is this happening, or at least, how to revert to the expected behavior?  I looked at , and I am not sure it applies, but here's /etc/ufw/before.rules  # # rules.before # # Rules that should be run before the ufw command line added rules. Custom # rules should be added to one of these chains: #   ufw-before-input #   ufw-before-output #   ufw-before-forward #  # Don't delete these required lines, otherwise there will be errors *filter :ufw-before-input - [0:0] :ufw-before-output - [0:0] :ufw-before-forward - [0:0] :ufw-not-local - [0:0] # End required lines   # allow all on loopback -A ufw-before-input -i lo -j ACCEPT -A ufw-before-output -o lo -j ACCEPT  # quickly process packets for which we already have a connection -A ufw-before-input -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A ufw-before-output -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A ufw-before-forward -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT  # drop INVALID packets (logs these in loglevel medium and higher) -A ufw-before-input -m conntrack --ctstate INVALID -j ufw-logging-deny -A ufw-before-input -m conntrack --ctstate INVALID -j DROP  # ok icmp codes for INPUT -A ufw-before-input -p icmp --icmp-type destination-unreachable -j ACCEPT -A ufw-before-input -p icmp --icmp-type source-quench -j ACCEPT -A ufw-before-input -p icmp --icmp-type time-exceeded -j ACCEPT -A ufw-before-input -p icmp --icmp-type parameter-problem -j ACCEPT -A ufw-before-input -p icmp --icmp-type echo-request -j ACCEPT  # ok icmp code for FORWARD -A ufw-before-forward -p icmp --icmp-type destination-unreachable -j ACCEPT -A ufw-before-forward -p icmp --icmp-type source-quench -j ACCEPT -A ufw-before-forward -p icmp --icmp-type time-exceeded -j ACCEPT -A ufw-before-forward -p icmp --icmp-type parameter-problem -j ACCEPT -A ufw-before-forward -p icmp --icmp-type echo-request -j ACCEPT  # allow dhcp client to work -A ufw-before-input -p udp --sport 67 --dport 68 -j ACCEPT  # # ufw-not-local # -A ufw-before-input -j ufw-not-local  # if LOCAL, RETURN -A ufw-not-local -m addrtype --dst-type LOCAL -j RETURN  # if MULTICAST, RETURN -A ufw-not-local -m addrtype --dst-type MULTICAST -j RETURN  # if BROADCAST, RETURN -A ufw-not-local -m addrtype --dst-type BROADCAST -j RETURN  # all other non-local packets are dropped -A ufw-not-local -m limit --limit 3/min --limit-burst 10 -j ufw-logging-deny -A ufw-not-local -j DROP  # allow MULTICAST mDNS for service discovery (be sure the MULTICAST line above # is uncommented) -A ufw-before-input -p udp -d 224.0.0.251 --dport 5353 -j ACCEPT  # allow MULTICAST UPnP for service discovery (be sure the MULTICAST line above # is uncommented) -A ufw-before-input -p udp -d 239.255.255.250 --dport 1900 -j ACCEPT  # don't delete the 'COMMIT' line or these rules won't be processed COMMIT   PS: I didn't expect this to "fix" the issue but just for reference I changed the port SSHD listens on (and the corresponding rule) and the problem persists.