How to prepend multiple lines to a file
How can I prepend a tag to the beginning of several files?
"the police conspiracy" vs. "the police's conspiracy" Why can't I find any manpages? I'm working on a Power8 server running Ubuntu 16.04.2 LTS:  $ uname -a     Linux power 4.4.0-75-generic #96-Ubuntu SMP Thu Apr 20 09:55:30 UTC 2017 ppc64le ppc64le ppc64le GNU/Linux  $ cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.2 LTS"   None of the usual manpages appear to be installed. Even a simple command like:  man man   returns   No manual entry for man See 'man 7 undocumented' for help when manual pages are not available.   This goes for a variety of other tools, like ls, grep, etc. and library functions like usleep, printf, and so on.  I've checked that at least some manpages are actually installed:  $ dpkg -l | grep -i manpages ii  manpages                           4.04-2                                     all          Manual pages about using a GNU/Linux system ii  manpages-dev                       4.04-2                                     all          Manual pages about using GNU/Linux for development ii  manpages-posix                     2013a-1                                    all          Manual pages about using POSIX system ii  manpages-posix-dev                 2013a-1                                    all          Manual pages about using a POSIX system for development   Am I missing something? Is this specific to the ppc64le architecture? Or is there something else I can/should install to access these manpages?  Update: As requested, I ran sudo mandb. The result was:  0 man subdirectories contained newer manual pages. 0 manual pages were added. 0 stray cats were added. 2 old database entries were purged.   There were no changes to man man and other such commands.  Additionally, the output of manpath was:  $ manpath -g /usr/man:/usr/share/man:/usr/local/man:/usr/local/share/man:/usr/X11R6/man:/opt/man $ manpath -c /var/cache/man/oldlocal:/var/cache/man/local:/var/cache/man Cycles Normal Bake does'nt bake indents that are not tapered Proving that the difference of the terms of a sequence, multiplied by $n$ converge Let $b_n$ decrease monotonically to zero, prove $\sum b_nz^n$ converges for $|z|\leq 1$ and $z\neq 1$ I'm trying to compose a cone in Inkscape, embedding text, image (after converted in vectors):   But, after importing in Blender, here is what I get:   You see then that something went wrong, but I don't know what. Please your advise is welcome !  JF I ran into this site:  But I can't find it on here:  Is it even an &quot;official&quot; Stack Exchange project? How can I disable Amazon search results in the Dash? Capacitor on USB cable? I was messing around with a USB camera. I wanted to change the cable because is trimmed but as I was cutting it I saw a small thing (image below). As I was trying to cut the casing and see what it has inside I saw a spark. I tried to connect it with another cable but I don't know if I'm gonna damage the camera or the USB port.    What is it and can I connect the camera without it? Is there a way to do concurrent editing? Is there a MediaWiki-like method for supporting concurrent editing of text bodies in Drupal 7?  If no feature currently exists, what are some decent PHP diff libraries that could be wrapped up by a Drupal module that could do the job? We're all familair with this beautiful proof whether or not an irrational number to an irrational power can be rational. It goes something like this:  Take $(\sqrt{2})^{\sqrt{2}}$  If it's rational, then you proved it, if it's irrational, take $((\sqrt{2})^{\sqrt{2}} ){^\sqrt{2}} = 2$ and you've proved it.  I'm wondering if you can raise $\pi$ or $e$ to a certain non-trivial real power to make it rational? And if not, where is the proof that it can't be done?   p.s. - I almost left out the real part, but then I realized that $e^{i\pi} = -1$. I am looking at the circuit diagram from   The gnucap description for it is given as C1 0 2 1UF R1 1 2 1K R2 0 2 1K Vin 0 1 AC 1 .OPTIONS PHASE=RADIANS .PRINT OP V(Vin) .OP 0.00 100.00 BY 10.00 BASIC .END  I can run the simulation on this using gnucap fine, see output. But is there a way to generate the schematic visually from just the textual description above using a simple command line tool? Is it possible to dual boot two OS's at the same time? What's the physical meaning of the imaginary component of impedance? As you know, impedance is defined as a complex number.  Ideal capacitors: $$ \frac {1} {j \omega C} \hspace{0.5 pc} \mathrm{or} \hspace{0.5 pc} \frac {1} {sC} $$  Ideal inductors: $$ j \omega L \hspace{0.5 pc} \mathrm{or} \hspace{0.5 pc} sL $$  I know that the reason why they 'invented' the concept of impedance is because it makes it easy to work with circuits in the frequency domain (or complex frequency domain).  However, since in real-life circuits both voltages and currents are real numbers, I'm wondering if there is any actual physical meaning behind the imaginary component of impedance. How do I fix "Error C1033: cannot open program database"? Windows 10 K&N Edition Anniversary update - Media player update not working I own a Windows 10 K or N Edition which doesn't include the media player package. My problem is: I want to have preview thumbnails in the explorer for my MP3s and videos.  I had the issue before when I updated to Win10 but there  saved me. Since the Anniversary update they are gone again.   Now I can install the old update but I still don't get the media player nor the preview images.  I tried most of the things Microsoft offers me but they are either not installable or don't work.  Any ideas what might be the correct update package?  Thx!  Ron How to show $d(x,y)= \sqrt{d_1(x_1,y_1)^2+d_2(x_2,y_2)^2}$ is a metric? $d_1(x_1,y_1)$ and  $d_2(x_2,y_2)$ are metric on $X$ and $d(x,y)$ is defined as: $$d(x,y)= \sqrt{d_1(x_1,y_1)^2+d_2(x_2,y_2)^2}.$$ I am trying to show this is a metric. Can you give me some clue about proving the triangle inequality for $d$ ? Thank you for your help. Although Ubuntu 16.04 release notes mention that:  The default VIM package has been built against python3 instead of python2.  Yet after I installed vim with the following command:  sudo apt-get install vim   And checked:  vim --version   It showed:  -python -python3   Is it a bug? How do I get vim with Python support? I recently installed Lubuntu but I have a problem with Adobe Flash Player. I always see something that looks like this when I open a video:    (source: )    The video is small, grainy, and is green and purple.  I tried to reinstall Flash and to test it in multiple browsers without success. I installed an older version of Flash but no result.  [0300]: Intel Corporation 82865G Integrated Graphics Controller [8086:2572] (rev 02)     Subsystem: Hewlett-Packard Company D530 sff(dc578av) [103c:12bc]     Kernel driver in use: i915 Tracking very long shot with no points in common between first and last frame Is it possible to track an handheld shot (there is already an answer on here about tripod shots: ) that doesn't have any visible points in common between the first and the last frame? As an example, imagine a shot of someone driving in a car for thirty minutes. Obviously everything from the first couple of seconds won't be there anymore at minute 15.