Difference between revisions of "Ubuntu 20.4"

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==Installing Software==
 
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===General Things===
 
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Install Languages following request
 
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Install gnome-tweak-tool and synaptic
 
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sudo apt-get install gnome-tweaks
 
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sudo apt-get install synaptic
 
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Choose Workspaces static. This and the number of workspace is changed with gnome tweak tool
 
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Install Extras
 
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sudo apt-get install ubuntu-restricted-extras
 
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sudo apt-get install flashplugin-installer
 
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sudo apt-get install nautilus-dropbox
 
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sudo apt-get install libappindicator1
 
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sudo apt-get install rar
 
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To enable Control-Alt-Backspace to kill X server
 
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sudo dpkg-reconfigure keyboard-configuration
 
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hit enter to accept curernt values until you get to the item Control-Alt-Backspace
 
  
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To Hide User List in Ubuntu 18.04 Login Screen
 
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Become root
 
−
 
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sudo -i
 
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Then switch to user gdm, which is required to run gsettings to configure gdm settings.
 
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su gdm -s /bin/bash
 
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Finally hide user list from login screen using Gsettings:
 
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gsettings set org.gnome.login-screen disable-user-list true
 
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Install unison
 
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sudo apt-get install unison
 
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sudo apt-get install unison-gtk
 
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Install keepassx: use synaptic
 
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Install sshd in the server
 
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sudo apt install openssh-server
 
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Then enable Xforward in /etc/ssh/ssh_config an /etc/sshd_config
 
−
 
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To have passwords stored
 
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sudo apt-get install libgnome-keyring0
 
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===Skype===
 
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Open "Software & Updates" and enable Canonical partners repository under Other Software tab.
 
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Then do
 
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sudo apt-get update
 
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sudo apt-get install skypeforlinux
 
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===Telegram===
 
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Install with
 
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sudo snap install telegram-desktop
 
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===Emacs and LaTeX (and Text in general)===
 
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For editing and text processing install: emacs, latex, ispell, auctex
 
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sudo apt-get install emacs texlive auctex bibtool
 
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sudo apt-get install texlive-bibtex-extra texlive-formats-extra texlive-fonts-extra texlive-lang-portuguese texlive-science
 
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sudo apt-get install ispell iportuguese
 
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sudo apt-get install latex2html
 
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sudo apt install texlive-publishers
 
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sudo apt install texlive-pstricks
 
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For latex2html copy the file .latex2html-init from the previous installation to preserve your definitions.
 
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For auctex to work you have to add the following lines to your .emacs file
 
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(require 'tex-site)
 
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(add-hook 'LaTeX-mode-hook 'turn-on-reftex)
 
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(setq reftex-enable-partial-scans t)
 
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(setq reftex-save-parse-info t)
 
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(setq reftex-use-multiple-selection-buffers t)
 
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(setq reftex-plug-into-AUCTeX t)
 
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(setq reftex-texpath-environment-variables '("TEXINPUTS"))
 
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(setq reftex-bibpath-environment-variables '("BIBINPUTS"))
 
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Emacs: To change between fixed number of columns and wrap text
 
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Writing with emacs is simpler in auto-fill-mode with a fixed number of columns (70 for instance). But sometimes we have to copy this text into online forms where you want it wrapped. To do this do the following
 
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Change into a fill mode with a large number of columns. For example 10000 columns
 
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C-x f 10000
 
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Select a paragraph and set auto fill
 
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M-x fill-individual-paragraphs
 
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In my case I have the F4 key to do this in the .emacs file
 
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If you want you can set back to 70 columns
 
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C-x f 70
 
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Problem with d-bus. If you get
 
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(emacs:24886): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
 
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Failed to connect to socket /tmp/dbus-7vPUX2fQ7b: Connection refused
 
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it is probbaly caused by .dbus subdir being owned by root:root. Change it
 
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sudo chown -R user:user .dbus
 
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How to print in color with a2ps
 
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a2ps --pro=color -o output.ps infile.txt
 
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or for output in one page
 
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a2ps -1 --pro=color -o output.ps infile.txt
 
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Problem with indent in environment align
 
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Customize LaTeX-indent-environment-list:
 
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M-x customize-variable RET
 
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LaTeX-indent-environment-list RET
 
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and uncheck align and align*
 
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The changes are save in .emacs
 
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To change tab space in a file
 
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M-x set-variable RET
 
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tab-width RET
 
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4
 
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4 is an example of course. This works only for the session.
 
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===Email===
 
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For email install thunderbird and the extensions
 
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sudo apt-get install thunderbird
 
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sudo apt-get install xul-ext-ubufox xul-ext-calendar-timezones xul-ext-gdata-provider xul-ext-lightning   
 
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Add extensions:
 
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Provider for Google Calendar
 
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gContactSync
 
−
 
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===Chrome===
 
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Download from google the .deb package for 64 bits
 
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Install using
 
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dpkg -i google-chrome-stable-xxx
 
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If you have problems with dependencies do
 
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sudo apt-get install -f
 
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===Graphics===
 
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====Installation====
 
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For graphics and plots install: gnuplot, gimp,gv
 
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sudo apt-get install gnuplot gimp gv
 
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In gnuplot to see the options of a given terminal do
 
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test
 
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The 75 and 100 dpi fints are no longer installed by default, Install and set the path:
 
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sudo apt-get install xfonts-75dpi xfonts-100dpi
 
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xset +fp /usr/share/fonts/X11/75dpi/
 
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xset +fp /usr/share/fonts/X11/100dpi/
 
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====Problems====
 
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Problems with ImageMagick.
 
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sudo nano /etc/ImageMagick-6/policy.xml
 
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Comment the following lines
 
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<!--
 
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  <policy domain="coder" rights="none" pattern="PS" />
 
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  <policy domain="coder" rights="none" pattern="PS2" />
 
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  <policy domain="coder" rights="none" pattern="PS3" />
 
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  <policy domain="coder" rights="none" pattern="EPS" />
 
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  <policy domain="coder" rights="none" pattern="PDF" />
 
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  <policy domain="coder" rights="none" pattern="XPS" />
 
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-->
 
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To avoid warnings in convert use
 
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convert -quiet
 
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====Tricks for gnuplot====
 
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Make 1D histograms with gnuplot
 
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binwidth=2
 
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bin(x,width)=width*floor(x/width)
 
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plot 'file.dat' using (bin($1,binwidth)):(1.0) smooth freq with boxes
 
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===Compilers and Maths====
 
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====gnu compilers, at and octave====
 
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sudo apt-get install build-essential
 
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sudo apt-get install at
 
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sudo apt-get install octave
 
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====Mathematica====
 
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Install fonts for Mathematica (if not yet installed)
 
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sudo apt-get install ttf-mscorefonts-installer
 
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To mount the server to get Mathematica at IST do
 
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sudo apt-get install cifs-utils
 
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mkdir Mathematica
 
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sudo mount -t cifs -o user=istxxxxx //delta.tecnico.ulisboa.pt/Mathematica Mathematica
 
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Copy the folder and install
 
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====Fortran====
 
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Install ifort copying what is in /opt
 
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Install prgrams in /usr/local. Normally just copy them there from the Backup
 
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====LoopTools====
 
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To be able to use the ifort compiler compile and install in an user directory. This is because then ifort is defined in the shell. The commands are
 
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./configure
 
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make install
 
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make -f makefile.quad-ifort install
 
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Then copy the subdirs in x86_64-Linux to /usr/local/lib/LoopTools
 
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To be able to use LoopTools in quad precision there is no need to use F90, but you have to change the program as follows
 
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Change real*8 into real*16 and complex*16 into complex*32
 
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Change all the double precision constants. For instance 2d0 goes into 2q0
 
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The Fortran flags must be like in the following Makefile
 
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FC        = ifort
 
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LT   = /usr/local/lib/LoopTools
 
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FFLAGS   =  -c -O -r16 -DDBLE=QEXT -DDIMAG=QIMAG -DDCONJG=QCONJG -DDCMPLX=QCMPLX -I$(LT)/include
 
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LDFLAGS    = 
 
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LINKER   = $(FC)
 
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LIB        = -L$(LT)/lib64  -L/usr/local/lib/Cuba
 
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LIBS      = -looptools-quad  -lcuba
 
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.F.o:
 
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$(FC) $(FFLAGS) $*.F
 
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.f.o:
 
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$(FC) $(FFLAGS) $*.f
 
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files = FinalResult-quad.o
 
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all: $(files)
 
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$(LINKER) $(LDFLAGS) -o FinalResult-quad $(files) $(LIB) $(LIBS)
 
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The reason for the above flags is explained by Thomas Hahn (LoopTools) as follows
 
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1. The 'barefoot' method is: replace all REAL*8 or double precision
 
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  by REAL*16, and COMPLEX*16 or double complex by COMPLEX*32.
 
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  You don't strictly need F90 for that but the only compilers
 
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  able to do it are F90 compilers anyway (except for some old
 
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  Unix flavors) and you don't need to change the code to
 
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  free-format F90 since F90 will also understand fixed-format F77.
 
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2. If you have a double-precision program, the compiler can
 
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  automatically upgrade it to quadruple precision, using
 
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  -r16 (ifort) or -fdefault-real-8 (gfortran).  There is one
 
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  catch, however: explcitly typed Fortran functions won't be
 
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  upgraded.  For example, if you wrote y = dsin(x), rather than
 
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  y = sin(x), the sine will not be upgraded to quad precision.
 
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  And even if you did your homework, there are four functions
 
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  which are not automatically upgraded: DBLE, DIMAG, DCONJG,
 
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  and DCMPLX.  That is, if you write y = CONJG(x) this is not
 
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  type independent but truncates x to single precision before
 
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  assigning to y.
 
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  That said, in my own programs I spell out those four functions
 
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  in CAPS so that I can easily replace them with compiler flags, too:
 
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  -DDBLE=QEXT -DDIMAG=QIMAG -DDCONJG=QCONJG -DDCMPLX=QCMPLX
 
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Upshot: while the second part seems much more work than the first,
 
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if you stick to some (relatively simple) coding rules (prefer
 
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untyped functions over typed functions, write out the four functions
 
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above in CAPS) you can just switch to double precision with compiler
 
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flags, which is just what LoopTools does.
 
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In a nutshell:
 
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- dsin -> sin, datan -> atan, csqrt(x) -> sqrt(DCMPLX(x)), etc.
 
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- dreal -> DBLE, dble -> DBLE, dconjg -> DCONJG etc.
 
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- compile with
 
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  -r16 -DDBLE=QEXT -DDIMAG=QIMAG -DDCONJG=QCONJG -DDCMPLX=QCMPLX (ifort)
 
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  -fdefault-real-8 -DDBLE=QEXT -DDIMAG=QIMAG -DDCONJG=QCONJG -DDCMPLX=QCMPLX (gfortran)
 
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Let me finally point out the subtle difference between dreal and
 
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dble.  The former is a (non-standard, at least non-77-standard)
 
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function to take the real part, the second is a typecast (usually
 
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from double complex to double).  This explains why DBLE and DCMPLX
 
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but not why DCONJG etc. are special.
 
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===Apache MySQL and PHP Server===
 
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Install the LAMP Server: Apache, MySQL and PHP
 
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sudo apt-get install apache2
 
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sudo apt-get install php php-cgi libapache2-mod-php php-common php-pear php-mbstring
 
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For mysql things have changed. After installation
 
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sudo apt install mysql-server
 
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you have to run
 
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sudo mysql_secure_installation
 
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answer yes to all questions and set the root password. To acces the mysql as root you have to be superuser
 
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sudo mysql -u root -p
 
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All users have to have a password.
 
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Enable cgi for PHP
 
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sudo a2enconf php7.2-cgi
 
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sudo systemctl reload apache2.service
 
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To enable User Dirs in public_html
 
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sudo a2enmod userdir
 
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sudo service apache2 restart
 
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To enable PHP in public_html: In /etc/apache2/mods-available/php7.0.conf, change the following
 
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<IfModule mod_userdir.c>
 
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    <Directory /home/*/public_html>
 
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        php_admin_flag engine Off
 
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    </Directory>
 
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</IfModule>
 
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to
 
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#<IfModule mod_userdir.c>
 
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#    <Directory /home/*/public_html>
 
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#        php_admin_flag engine Off
 
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#    </Directory>
 
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#</IfModule>
 
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Copy from the old system the sites available that you want to keep and enable them
 
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sudo aensite site_name
 
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Note:The sites available have to have the .conf extension to be read by a2ensite
 
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To avoide the error "Could not reliably determine the server's fully qualified domain name", create the file
 
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sudo nano /etc/apache2/conf-available/fqdn.conf
 
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and write there
 
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ServerName localhost or proper name if you have one
 
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then
 
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sudo a2enconf fqdn
 
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To check missing links in web sites install
 
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sudo apt-get install linkchecker
 
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sudo apt-get install linkchecker-gui
 
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===Allowing www-data group in UserDir directories===
 
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Sometimes you want some programs in your public_html directory. For that you have to ask the system manager to do the following
 
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First, add yourself into the group www-data
 
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sudo usermod -a -G www-data (your username)
 
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Then:
 
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sudo chgrp www-data /home/myuser/public_html/folderA
 
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sudo chmod g+rwxs /home/myuser/public_html/folderA
 
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Should do the trick unless the permissions on your /home/myuser do not permit other users access. The first command changes the group ownership of the folder to that of the webserver. The second command gives members of the www-data group read, write, enter-directory rights, and the group s flag will ensure that any files that get created inside that directory take www-data as the group - so if you create a file as myuser the www-data user will have access.
 
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===Install Apache with SSL===
 
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Get the software if not yet installed
 
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sudo apt-get install apache2
 
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sudo apt-get install ssl-cert
 
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Enable ssl
 
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sudo a2enmod ssl
 
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Configure ssl
 
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sudo cp /etc/apache2/sites-available/default-ssl.conf /etc/apache2/sites-available/ssl.conf
 
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sudo a2ensite ssl
 
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sudo service apache2 restart
 
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The file /etc/apache2/sites-available/ssl.conf looks like
 
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<IfModule mod_ssl.c>
 
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<VirtualHost _default_:443>
 
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ServerAdmin webmaster@localhost
 
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DocumentRoot /var/www/htmls
 
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# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
 
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...
 
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</VirtualHost>
 
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</IfModule>
 
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To password protect in /etc/apache2/sites-available/ssl.conf, insert before </VirtualHost>
 
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<Directory "/var/www/htmls/some_dir>
 
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AuthType Basic
 
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AuthName "Restricted Files"
 
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AuthUserFile /etc/apache2/passwd/passwords
 
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Require user some_user
 
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</Directory>
 
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Passwords are created with the command
 
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sudo htpasswd
 
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To list options
 
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htpasswd --help
 
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===Install SSL Certificates===
 
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This is taken from https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-ubuntu-16-04
 
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Introduction
 
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This tutorial will show you how to set up a TLS/SSL certificate from Let’s Encrypt on an Ubuntu 16.04 server running Apache as a web server. We will also cover how to automate the certificate renewal process using a cron job.
 
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SSL certificates are used within web servers to encrypt the traffic between the server and client, providing extra security for users accessing your application. Let’s Encrypt provides an easy way to obtain and install trusted certificates for free.
 
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Prerequisites
 
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An Ubuntu 16.04 server with a non-root sudo user, which you can set up by following our Initial Server Setup guide The Apache web server installed with one or more domain names properly configured through Virtual Hosts that specify ServerName. When you are ready to move on, log into your server using your sudo account.
 
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Step 1 — Install the Let's Encrypt Client
 
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First, we will download the Let’s Encrypt client from the official repositories. Although the Let's Encrypt project has renamed their client to certbot, the client included in the Ubuntu 16.04 repositories is simply called letsencrypt. This version is completely adequate for our purposes.
 
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sudo apt-get update
 
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sudo apt-get install python-letsencrypt-apache
 
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The letsencrypt client should now be ready to use.
 
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Step 2 — Set Up the SSL Certificate
 
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Generating the SSL Certificate for Apache using the Let’s Encrypt client is quite straightforward. The client will automatically obtain and install a new SSL certificate that is valid for the domains provided as parameters.
 
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To execute the interactive installation and obtain a certificate that covers only a single domain, run the letsencrypt command like so, where example.com is your domain:
 
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sudo letsencrypt --apache -d example.com
 
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After the dependencies are installed, you will be presented with a step-by-step guide to customize your certificate options. You will be asked to provide an email address for lost key recovery and notices, and you will be able to choose between enabling both http and https access or forcing all requests to redirect to https. It is usually safest to require https, unless you have a specific need for unencrypted http traffic.
 
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When the installation is finished, you should be able to find the generated certificate files at /etc/letsencrypt/live. You can verify the status of your SSL certificate with the following link (don’t forget to replace example.com with your base domain):
 
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https://www.ssllabs.com/ssltest/analyze.html?d=example.com&latest You should now be able to access your website using a https prefix.
 
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Step 3 — Set Up Auto Renewal
 
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Let’s Encrypt certificates are valid for 90 days, but it’s recommended that you renew the certificates every 60 days to allow a margin of error. The Let's Encrypt client has a renew command that automatically checks the currently installed certificates and tries to renew them if they are less than 30 days away from the expiration date.
 
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To trigger the renewal process for all installed domains, you should run:
 
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sudo letsencrypt renew
 
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Because we recently installed the certificate, the command will only check for the expiration date and print a message informing that the certificate is not due to renewal yet. The output should look similar to this:
 
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  Processing /etc/letsencrypt/renewal/example.com.conf
 
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  The following certs are not due for renewal yet:
 
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    /etc/letsencrypt/live/example.com/fullchain.pem (skipped)
 
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    No renewals were attempted.
 
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A practical way to ensure your certificates won’t get outdated is to create a cron job that will periodically execute the automatic renewal command for you. Since the renewal first checks for the expiration date and only executes the renewal if the certificate is less than 30 days away from expiration, it is safe to create a cron job that runs every week or even every day, for instance.
 
−
Include the following content at the end of the crontab, all in one line:
 
−
 
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30 2 * * 1 /usr/bin/letsencrypt renew >> /var/log/le-renew.log
 
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Save and exit. This will create a new cron job that will execute the letsencrypt-auto renew command every Monday at 2:30 am. The output produced by the command will be piped to a log file located at /var/log/le-renewal.log.
 
−
 
−
===OwnCloud and SSL===
 
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===OwnCloud Upgrades===
 
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===OwnCloud Upload Folders===
 
−
===Owncloud Repair Files===
 
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===Owncloud Unlock Files===
 
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===MySQL===
 
−
===PHP===
 
−
====Installation Questions====
 
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====Connection with MySQL====
 
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====To use with Emacs====
 
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===MediaWiki===
 
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====Install Mediaki in Ubuntu 16.04====
 
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====Export the Mediawiki Database in SQL====
 
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====Export into site with all the files====
 
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====Import the Mediawiki Database in SQL====
 
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====Import the Mediawiki Database in from HTML====
 
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====Secure LocalSettings.php====
 
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====Cleaning====
 
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====Change Setting to see errors====
 
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===Java===
 
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===Adobe Reader===
 
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===Rotate a PDF under Ubuntu Linux===
 
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===Dvips fonts===
 
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===Sendmail and alpine===
 
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===Other Software===
 
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===MS Fonts===
 
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===Firewall===
 
−
===Stop avhai-deamon===
 
−
 
−
==Tunning==
 
−
===Grub screen resolution===
 
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===Disable Password after Suspend===
 
−
===Cleaning up===
 
−
===Change boot order in grub===
 
−
===Setting smart host in sendmail===
 
−
===System Load Indicator===
 

Latest revision as of 13:23, 20 October 2020

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