Could not set the configuration for crtc 64 (15.04)

Based on the specifications for your external screen, I recommend that you change the settings to match it's native resolution. Based on your xrandr output you've got it configured for 1600x1200 @ 60 Hz One of the things the manufacturer suggests doing (in the manual) before contacting the iiyama information line is to check "if the correct native resolution has been selected via 'Display Properties".

To set things up to use the manufacturers recommended resolution you would generate a modeline with cvt. Since this is a TFT display and I can't find any indication to the contrary I'm using a refresh rate of 60 to generate the modeline.

So you'd generate the modeline with:

cvt 1920 1080 60
Which results in output similar to this:

1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

Then you would apply the modeline with xrandr with:

xrandr --newmode Everything After Modeline from the cvt output
including the quotes and then

xrandr --addmode VGA1 1920x1080_60.00

Where VGA1 is the port your display is connected to and the remainder of the line is everything between quotes from the cvt output

Sources:

https://www.manualslib.com/manual/673627/Iiyama-Prolite-E2407hds.html#manual

http://www.kmart.com/asus-n56j-15.6inch-notebook-with-intel-core-i7/p-020V007360940000P

http://www.manualmonitor.com/manuals/iiyama/Iiyama_ProLite_E2407HDS-1.pdf

https://help.ubuntu.com/community/NvidiaResolutionXorgConf

How to set a custom resolution?


Go to the directory where you have your file (say file.bin) and ensure the permissions will allow you to run it:
chmod u+x file.bin

Then run it with either of:
./file.bin
sudo ./file.bin

You may alternatively have to use something like:
bash file.bin

You should refer to the installation instructions. If they're good, they will tell you exactly what you should do. If not, I'd be circumspect about the software since the developers aren't as good as they think they are :-)


Are there plans for a web Interface for Ubuntu Software Centre

You can find such an interface at http://apps.ubuntu.com.

It's at an early stage right now, so if you can suggest ways
of improving it, or want to help out with the changes then
you can join the mailing list to discuss it.


a stop after downoading packages during upgrading the system

CLI way
This should be possible by pausing the upgrade process.
First run the upgrade process
sudo do-release-upgrade

Now you should be seeing various output. When you wish, pause the command by giving a SIGTSTP signal by pressing the  Ctrl+Z keys.
You should now see something like
[1]+  Stopped                 sudo do-release-upgrade

You should NOT close the terminal. Now later, as per your wish, you could restart the process by typing
fg 1

where 1 is the job id that you see while pausing the command.
In case you forgot the job id, you can run
jobs

which will show you all list of jobs, like this
[1]+  Stopped                 sudo do-release-upgrade


Miro does not play Flash and HTML5 videos

I'd suggest you try this from user79939 at How can I watch the NBC Olympics 2012 (USA)?. If it works the basic problem is that the streams are protected content.

As per this post on the Adobe website:

Step One: Install HAL

sudo apt-get install hal

Step Two: Quit your web browser

Step Three: Clean out the Adobe Flash folder:

cd ~/.adobe/Flash_Player
rm -rf NativeCache AssetCache APSPrivateData2

This process worked for me.  In my case, I'd been able to go to nbcolympics.com and click the log to begin the verification process, but never given the chance to enter my Comcast credentials.  Doing the steps above fixed everything.


Error while setting up a RTMP Server - make error

Update your nginx.

Using the following command, gives the error.

$ wget http://nginx.org/download/nginx-1.9.15.tar.gz

Instead use,

$ wget https://nginx.org/download/nginx-1.10.1.tar.gz


The repository posted does not contain sources but the actual installed file system mangled into a git repository.

I have followed http://wiki.cyanogenmod.org/w/Unofficial_Ports#Samsung_Galaxy_S_Plus_.28GT-I9001.29 to fine a set of git repositories on which you can base on in https://github.com/skywalker01

The bad news is that the Galaxy S Plus is based out of gingerbread and our Ubuntu Touch code base is based out of jellybean+, which means more work than just following the generic porting guide would need to happen.


15.10 very slow during file operations, despite 16GB RAM good CPU and no apps running

If you have an HDD, try the CFQ I/O scheduler. Here's how to do it:

sudo -H gedit /etc/default/grub

Change:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash elevator=cfq"

Then run:

sudo update-grub

For more explanation google "enable cfq in ubuntu".


Sending packets between interfaces using ping

PING is a type of packet, so you can't send packets using ping.

Ping is an "echo request" and pong is an "echo response".

These packets are used to check if the other side is reachable and responding.


Ubuntu Update problem | 16.04 ; cannot complete the update

The ppa you are using does not have packages available for 16.04, that is the meaning of the 404 error.

Disable the ppa or contact the maintainer.

See also How can I fix a 404 Error when using a PPA or updating my package lists?


How to set the hide Time of the Launchbar higher?

That is a hard coded value.  There is no configuration option to change it.

To change it you would have to recompile the software yourself with the change you want, which can be painful and be a massive headache from a package management perspective.  There is also no guarantee that a recompiled version will work as nicely either.


Unable to set public static IP ubuntu 18.04.1 amd 64 during install

You are mixing up notation method, and using a subnet mask as your subnet definition. You should define your subnet as 192.168.0.40/29.


mysqldump: Error 2013: Lost connection to MySQL server during query when dumping table

The solution was prety easy. This problem happend becouse when the dump is passing throug an ssh canal, and an opperation like "alter" is running, the data transfer needs to be stoped wating for the querie to finish. The time that the connection will wait to new data is defined in my.cnf in a really low time (30 seconds by default).

For fix this error, the only thing needed is modify this two params on the mysql config:

net_read_timeout    = 3600
net_write_timeout   = 3600

This will prevent the connection to get a timeout and prompt this error.

Due to the docu, is defined as:

  The number of seconds to wait for more data from a connection before
  aborting the read. When the server is reading from the client,
  net_read_timeout is the timeout value controlling when to abort. When
  the server is writing to the client, net_write_timeout is the timeout
  value controlling when to abort. See also slave_net_timeout.


There's some issue with the Ubuntu CD on D:. Remove it and run wubi.exe standalone. It will download a preinstalled, compressed disk image (a little over 500MB) and install from that.

The other thing you can do is remove the CD, but use the ISO you used to create the CD. Just place the ISO and wubi.exe in the same folder before running Wubi. (Make sure the disk in D: has been removed.

In terms of what the real problem is, [Errno13] doesn't give much information. It's found a valid CD, but fails to copy it:

01-22 23:14 DEBUG  Distro:   checking whether D:\ is a valid Ubuntu CD
01-22 23:14 INFO   Distro: Found a valid CD for Ubuntu: D:\
...
01-22 23:14 DEBUG  TaskList: ## Finished copy_installation_files
01-22 23:14 DEBUG  TaskList: ## Running get_iso...
01-22 23:14 DEBUG  TaskList: New task copy_file
01-22 23:14 DEBUG  TaskList: ### Running copy_file...
01-22 23:15 ERROR  TaskList: [Errno 13] Permission denied
Traceback (most recent call last):
  File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__
  File "\lib\wubi\backends\common\utils.py", line 202, in copy_file

You can search for related bugs - the CD may be readable but corrupt in some way... but no way to know for sure.


How to increase swap size when there is already a partition existing

If you don't want to re-partition you can use a swap file. It works like it does on Windows.  Instead of specifying a partition name in your fstab, you specify a file, say, in your root partition.

You will need to initialise the file simply by creating a file containing zeros of your desired size, and make it readable only by root.  Also (I can't remember if this is necessary) format it with:

sudo mkswap /myswapfile

Here are some full instructions:

https://support.rackspace.com/how-to/create-a-linux-swap-file/

(It's strange they chose to put it in /mnt, that's not what /mnt is)

You can use the swap file in addition to your existing swap partition, and there should not be a performance hit.  You can even specify a priority in your fstab for what order they should be used, which is for when some of your swap is on a faster device, but that's not really relevant here.


What does the "p" in the first column of ls -la stand for?

p stands for (named) Pipe - see also https://en.wikipedia.org/wiki/Pipe_(Linux)


Is it possible to quickly enable/disable a monitor in a dual monitor set-up (desktop)?

Credit to MestreLion for making this solution possible.

Intense research later I found a related question on SO with this great script:

#!/bin/bash
#
# monitor-switch - switch outputs using xrand
#
#    Copyright (C) 2012 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program. See <http://www.gnu.org/licenses/gpl.html>

declare -A monitor_opts
declare -a monitors

myname="${0##*/}"
verbose=0

# Read settings from config file
config=${XDG_CONFIG_HOME:-"$HOME"/.config}/"$myname".conf
if [[ -f "$config" ]]; then
    source "$config"
fi

print_monitors() {
    while read -r output conn hex; do
        echo "# $output $conn   $(xxd -r -p <<<"$hex")"
    done < <(xrandr --prop | awk '
    !/^[ \t]/ {
        if (output && hex) print output, conn, hex
        output=$1
        hex=""
    }
    /ConnectorType:/ {conn=$2}
    /[:.]/ && h {
        sub(/.*000000fc00/, "", hex)
        hex = substr(hex, 0, 26) "0a"
        sub(/0a.*/, "", hex)
        h=0
    }
    h {sub(/[ \t]+/, ""); hex = hex $0}
    /EDID.*:/ {h=1}')
}

# if there's no pre-defined monitors list, read from xrandr
# and save them to config file
if [[ -z "$monitors" ]]; then
    while read -r output ; do
        monitors+=("$output")
    done < <(xrandr | awk '$2 ~/^c/{print $1}' | sort)
    cat > "$config" <<-EOF
        # $myname config file
        # List of monitors, from left to right. Edit to your actual layout
        monitors=(${monitors[@]})
        # Extra xrandr options for each monitor.
        # Useful when EDID data does not reflect actual preferred mode
        # Options for non-existing outputs (such as the examples below) are ignored
        # Examples:
        monitor_opts[DFPx]="--mode 1920x1080 --rate 60"
        monitor_opts[DFPy]="--mode 1280x720"
        # As a reference, these were the connected monitors when this config file was created
        # use it as a guide when editing the above monitors list and extra options
        $(print_monitors)
        # For an updated list, run $myname --list
    EOF
fi

message() { printf "%s\n" "$1" >&2 ; }
fatal()   { [[ "$1" ]] && message "$myname: error: $1" ; exit ${2:-1} ; }
argerr()  { printf "%s: %s\n" "$myname" "${1:-error}" >&2 ; usage 1 ; }
invalid() { argerr "invalid argument: $1" ; }
missing() { argerr "missing ${2:+$2 }operand${1:+ from $1}." ; }

usage() {
    cat <<-USAGE
    Usage: $myname [options]
    USAGE
    if [[ "$1" ]] ; then
        cat >&2 <<- USAGE
        Try '$myname --help' for more information.
        USAGE
        exit 1
    fi
    cat <<-USAGE
    Switch monitors using xrandr.
    Options:
      -h|--help          - show this page.
      -v|--verbose       - print in terminal the full xrandr command executed.
      -l|--list          - list connector and monitor names of connected outputs
      -a|--all           - enable all monitors.
      -s|--select OUTPUT - enable monitor OUTPUT, disable all others.
      -l|--left          - enable leftmost monitor.  Alias for --select ${monitors[0]}
      -r|--right         - enable rightmost monitor. Alias for --select ${monitors[${#monitors[@]}-1]}
    Copyright (C) 2012 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
    License: GPLv3 or later. See <http://www.gnu.org/licenses/gpl.html>
    USAGE
    exit 0
}

# Option handling
for arg in "$@"; do [[ "$arg" == "-h" || "$arg" == "--help" ]] && usage ; done
while (( $# )); do
    case "$1" in
    -v|--verbose) verbose=1 ;;
    -q|--no-notify) notify=0 ;;
    -l|--list) list=1 ;;
    -a|--all) all=1 ;;
    -s|--select) shift ; monitor="$1" ;;
    -l|--left ) monitor="${monitors[0]}" ;;
    -r|--right) monitor="${monitors[${#monitors[@]}-1]}" ;;
    *) invalid "$1" ;;
    esac
    shift
done

if ((list)); then
    echo "Connected monitors:"
    print_monitors
    exit
fi

if [[ -z "$monitor" && -z "$all" ]]; then
    usage
fi

# Loop outputs (monitors)
for output in "${monitors[@]}"; do
    if ((all)) || [[ "$output" = "$monitor" ]]; then
        xrandropts+=(--output "$output" --auto ${monitor_opts["$output"]})
        if ((all)); then
            if [[ "$output" = "${monitors[0]}" ]]; then
                xrandropts+=(--pos 0x0 --primary)
            else
                xrandropts+=(--right-of "$previous")
            fi
            previous="$output"
        else
            xrandropts+=(--primary)
        fi
    else
        xrandropts+=(--output "$output" --off)
    fi
done

((verbose)) && message "$myname: executing xrandr ${xrandropts[*]}"
xrandr "${xrandropts[@]}"

The code is also shared on Github.

With this script mapped to a keyboard shortcut I can easily switch monitors:

monitor-switch --left
monitor-switch --right

The script also creates a configuration file in /home/.config/monitor-switch.conf. This 3 lines config file allow for two things to be registered:

The physical layout of the screens: which one is on the left/right of the other. Which is great when your main display is on the right of your secondary display (my case).
The mode to use when a monitor is turned on (default being xrandr --auto). In mine for instance I can save monitor_opts[DP-2]="--mode 1920x1080 --rate 144"


How to hide mounted partitions and devices from Unity Launcher via Command Line?

From terminal:

Hide mounted partition or devices:
  gconftool --set /apps/compiz-1/plugins/unityshell/screen0/options/devices_option  --type=int 0

Show mounted partition or devices:
  gconftool --set /apps/compiz-1/plugins/unityshell/screen0/options/devices_option  --type=int 1


Video doesn't run when Jack Audio Connection Kit is on

The answer may be here
How to use JACK and Pulseaudio/ALSA at the same time on the same audio device?

It looks like this software: "pulseaudio-module-jack" is needed.  Chrome uses pulseaudio so jack needs to know how to work with pulseaudio.


When can I safely unplug an external drive on 12.10?

Perhaps a BASH script on the Desktop might suffice until the bug is fixed.
This solution is from Nikunj Lahoti. The software, udisks, can unmount and power down an external hard drive.

sudo apt-get install udisks

Then create a file (safelyremove.sh, perhaps) on the Desktop or a convenient place. Change /dev/sdc to your device. Make sure to include all partitions on the device.

#!/usr/bin/env bash

echo "Unmounting..."
udisks --unmount /dev/sdc1
udisks --unmount /dev/sdc2

echo "Spinning down..."
udisks --detach /dev/sdc

read -p "Done! Press [Enter] to exit."

Make the script executable. It will wait for [Enter] so you can see it is done.


Welcome to the family. Below are a few links that will help guide you through creating bootable media that will help you install Ubuntu Desktop. This guide will assume you're using a USB.

How to make bootable USB stick in Windows.
How to install Ubuntu Desktop (Also has DVD Guide)


So, after much research...

Ubuntu Installation stuck on "Restart Now"

https://gabstutorials.wordpress.com/2017/06/15/install-ubuntu-16-04-on-a-msi-gp62mvr-laptop/

http://www.linuxandubuntu.com/home/how-to-install-latest-nvidia-drivers-in-linux

  * I’ve had issues with the 16.04.3 update and clean install… I’m trying to figure out what went wrong with this update. Stay away from 16.04.3 for now

This is the same problem in 16.04.03, 16.04.04, and 17.10.1. Also has a different problem in 18.04-daily build (won't even start up installer). Steps I took to fix:

Install the latest BIOS.
Turn off secure boot.
Download ubuntu-16.04.4-desktop-amd64.iso
Download Rufus 2.8
Follow this tutorial on how to make a bootable USB
Follow this tutorial on how to install Ubuntu
The installer will complete, click Restart Now. This will not exit cleanly, force power off
Boot normally, do not login. Press Ctrl+Alt+F2, login.
Run the command: sudo apt-get purge nvidia* && sudo add-apt-repository ppa:graphics-drivers && sudo apt-get update && sudo apt-get install nvidia-384 -y
After it has finished run the command sudo shutdown -r now This may or may not exit cleanly, force power off if it does not
On next boot, everything should be working 100%.

tl;dr : Download newest BIOS for MSI gp62mvr-6rf, revert to default settings, turn off secure boot, install Ubuntu 16.04.04 (this will not cleanly install. Run sudo apt-get purge nvidia* && sudo add-apt-repository ppa:graphics-drivers && sudo apt-get update && sudo apt-get install nvidia-384 -y, then run: sudo shutdown -r now, force power off if necessary, boot, everything should be working.


Pointer won't display at the left edge of screen

I also have this problem on Ubuntu Mate 17.10, using an Acer Cloudbook with an Intel Celeron N3060 and Intel integrated graphics connected to an external monitor with an hdmi to dvi cable. I've been tempted to get an HDMI-> VGA converter based on your experience of the problem going away.

The problem is definitely connected to the Intel integrated graphics, since using the software compositor makes it go away. I can't find it at the moment, but someone posting a related problem was told that it was the cursor issue workaround for a larger bug and that is definitely true. I haven't yet determined a clear pattern, but whatever prevents the cursor from being shown on the left edge of the screen stops (i.e., the mouse can now be seen on right up against the edge) and then I get constant graphics glitches around the cursor, which disappear when I do a complete restart.

Edit: To be clear, using the software compositor stops the glitches, but just checking now with switching to the software compositor, it keeps the strange workaround of the mouse not being visible on the far left of the display if the glitches aren't happening before the switch.


I am having problems in booting up my Ubuntu 18.04

I am a novice myself, but during my installation I had a problem that I couldn't access the system. (I simply messed fstab up).
I used the installation USB stick and used the "Try Ubuntu" option.
I mounted the system disk (using Disks) and used the Terminal to correct the fstab. Fdisk is available on the installation usb.
I hope that helps a bit.


They have different recorded at volumes.  The only way I know to fix this is to use something like VLC's volume normalization, which is not desirable for many people in many instances.


What SSSD is (source: apt show sssd-common):

Description: System Security Services Daemon -- common files
Provides a set of daemons to manage access to remote directories and
authentication mechanisms. It provides an NSS and PAM interface toward
the system and a pluggable backend system to connect to multiple different
account sources. It is also the basis to provide client auditing and policy
services for projects like FreeIPA.

SSSD is not part of a stock Ubuntu Desktop install.
If you don't use a remote authentication server, then you likely don't need the SSSD packages at all.
If you do use a remote authentication server, then this failure may be important. Contact your network admin.


The 2D netbook interface from 10.04 is still there.  You can use it if you install ubuntu-netbook-efl-default-settings & netbook-launcher-efl (click the package names to install them, after installation there will be a new session choice in the login screen).

I don't understand why Docky would prevent you from running system administration programs?


Type your username, press Enter.
Type your password (no dots will appear), press Enter.
You are now logged in.


Assuming you want to cp files into a directory, you can use the usual syntax for cp:

cp mno.txt xyz.txt destination_directory

Or use brace expansion for brevity:

cp {mno,xyz}.txt destination_directory

For the sake of clarity, it is better to use the -t (--target-directory) option of cp, this is GNU-ism:

cp -t destination_directory {mno,xyz}.txt

Just to note, if you want to cp the contents of multiple files with one go of cp, you can't. cp deals with one file at a time when copying contents of one file to another.


Installing Ubuntu14.01 on virtualbox Erase disk?

TL;DR - any option is safe, option 1 being the easiest.

When you created the virtual machine to install Ubuntu on, Virtualbox asked you to create a virtual drive.

Unless you explicitly exposed your physical disks to your virtual machine (it's very unlikely you've done this accidentally), your virtual machine is constrained to that virtual disk (ATA VBOX HARDDISK(8.6GB)) which resides in a file on the physical disk.

Therefore you can do whatever you please from within that VM and it won't be able to touch anything outside that file, i.e. it won't affect anything on your Windows partition (except for space occupied by the virtual disk backing file, that is).


Stuck at black screen after waking up from suspension

I solved the issue by updating the kernel to 5.9.5 from 5.4. Works fine.


Ethernet Network Disconnecting - Atheros AR8152

I did fix it!
i did go to the connection icon and then to settings and deleted the ethernet connection!
so now it doesn't give me the error!


Go to Settings → Power → Blank Screen.

It's not an obvious place for the option but it does allow you to set different time options before the screen blanks.


How to avoid having newlines with grep -o for multiple match at the same line?

You can pipe the output of grep to tr that you can then use to translate \n (newline) to \t (tab):

echo "a b a" | grep -o a | tr "\n" "\t"; echo

where the last echo is used to prevent the output of tr from being on the same line as your PS1.

For the specific example you give, this is how it looks like:

$ echo "a b a" | grep -o a | tr "\n" "\t"; echo
a   a


How to get my wirleless adapter to work with Ubuntu 17.04

How are you going about installing packages? With apt-get? This here:

  The exact error I am getting for install for example.
  E: Package git has no installation candidate.

looks like you need to either fix your /etc/apt/sources.list or sources.list.d or you need to run apt-get update first, to fetch available packages.

The error:

  E: unable to locate package https://github.com/jurobystricky E: could find any package by glob AND regex (same address)

looks very suspicious to me. Never seen anything like that. Are you doing something like this: apt-get install https://github.com/jurobystricky. If you are, then that's not the way apt-get works. With apt-get you can only install packages that are available. You can get the list of available packages like this: https://superuser.com/questions/408082/how-do-i-get-a-list-of-available-i-e-uninstalled-packages-in-debian


Nice way to manage multiple Ubuntu servers

Maybe use puppet
Here You are an Example:
http://www.youtube.com/watch?v=Hiu_ui2nZa0


I just had a problem that looks a lot like yours.
Turns out the installer installed the boot loader on the USB key I was installing Ubuntu from.
I re-installed it using advanced settings, setting the boot loader to install to sda1 instead of sdb1 and it worked fine after.


Ubuntu 16.04 failed clean install on new hard drive

I found an answer that fixed it for me in this thread

http://www.linuxquestions.org/questions/linux-hardware-18/the-new-dell-xps-8900-a-4175559854/

When entering grub during installation, I changed the line to

    linux   /casper/vmlinuz.efi  file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash pcie_aspm=off ---

and that did the trick. I followed info in this link

After booting I made the fix permanent by editing the line in grub that starts “GRUB_CMDLINE_LINUX_DEFAULT” and adding the following:

quiet splash pcie_aspm=off


Found a solution in gpu passthrough. Requires using VFIO and assumes two video cards (onboard and a pci board): https://www.pugetsystems.com/labs/articles/Multiheaded-NVIDIA-Gaming-using-Ubuntu-14-04-KVM-585/


Offline installing libxml2-dev in Ubuntu 15.04

Go to a system with Internet access and download libicu-dev
via

wget http://mirrors.kernel.org/ubuntu/pool/main/i/icu/libicu-dev_52.1-8ubuntu0.2_amd64.deb

and install with

sudo dpkg -i libicu-dev_52.1-8ubuntu0.2_amd64.deb

Then install the libxml2-dev package again

sudo dpkg -i libxml2-dev_2.9.2+dfsg1-3_amd64.deb

However, it may be that you still need more packages. Unfortunately I can not say that because I do not know what you have already installed. But I think the way forward is clear. ;)

All packages are available here. Search the packages for Vivid (vivid and/or vivid-updates) and download the 64-bit versions. Use an USB stick and use this stick in your desktop system.


How do I install Realplayer to download FLV files?

You can easily do that installing an add-on in firefox. Don't need to install any program for that. Open firefox, go to the website with the flash video and click in download.

Here is the link to the add-on.


I resolved the issue by creating and adding lines to xorg.conf, ignoring whether stuff is working via xrandr.

This is still more or less within the bounds of what the guide at https://wiki.ubuntu.com/X/Config/Resolution suggested;

I just followed the advice in section 6 this time, rather than section 5.

My xorg.conf follows:

Section "Monitor"
    Identifier "External VGA"
    Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088
    1120 -hsync +vsync
    Option "Rotate" "normal"
    Option "PreferredMode" "1920x1080_60.00"
EndSection

Section "Screen"
    Identifier "Default Screen"
    Device "Configured Video Device"
    SubSection "Display"
        Virtual 1920 1080
    EndSubSection
EndSection

Section "Device"
    Identifier  "Configured Video Device"
EndSection


Bluetooth and wifi get switched on and off together

Here's what worked for me on a Dell XPS 17 L702X (it was also reported to work with Dell XPS 13 and Dell XPS 15 and maybe it works for you too). Open a terminal and copy/paste these commands:

echo "#fix dell wifi/bluetooth:" | sudo tee -a /etc/modprobe.d/blacklist.conf
echo "blacklist dell_laptop" | sudo tee -a /etc/modprobe.d/blacklist.conf

Then restart the laptop.

From here: Fix Dell XPS 13 Backlight Brightness Not Adjustable And Trackpad Not Working Properly In Ubuntu


Restart Network-Manager every n minutes/hours

The asker has stated that they eventually added the necessary paths to the top of the crontab file. I thought it useful to direct others searching through this thread to a little more information about the solution.

See: Reasons why crontab does not work

Quote:

  Cron passes a minimal set of environment variables to your jobs. To
  see the difference, add a dummy job like this:

  env > /tmp/env.output

  Wait for /tmp/env.output to be created, then remove the job again. Now
  compare the contents of /tmp/env.output with the output of env run in
  your regular terminal.

  A common "gotcha" here is the PATH environment variable being
  different. Maybe your cron script uses the command somecommand found
  in /opt/someApp/bin, which you've added to PATH in /etc/environment?
  cron does not read that file, so runnning somecommand from your script
  will fail when run with cron, but work when run in a terminal.

...

  You can also set the PATH variable in the crontab file, which will
  apply to all cron jobs. E.g.

> PATH=/opt/someApp/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
>
> 15 1 * * * backupscript --incremental /home /root


Why does my update manager always "fail to download package files"?

Ubuntu 11.04 is Natty Narwhal is no longer supported in any way. The repositories are not there any more.

The repositories still exist but have been moved and are no longer being updated.

If you want to continue using an outdated release then edit /etc/apt/sources.list and change archive.ubuntu.com to old-releases.ubuntu.com

I would not recommend this as there will be no more bug fixes, security patches etc

I strongly suggest you upgrade to 12.04 LTS. This will be easiest as a clean install. The alternative is to upgrade to 11.10 and then upgrade again.

I suggest you try a live CD/DVD of both Xubuntu and Ubuntu without installing as the desktop has changed significantly: Xubuntu is more like Ubuntu was in 10.04 and Ubuntu now uses Unity and this may be too slow on older hardware. Once you have decided which you prefer install it.

Downloads are here:
Ubuntu -- http://releases.ubuntu.com/precise/

Xubuntu -- http://xubuntu.org/getxubuntu/

You can of course go with 12.10 but not being an LTS release you will need to upgrade sooner.


How to sync files from two Operating Systems  to a same folder using U1?

If you add maybe your "documents" folder for syncing, which is inside your home folder, Ubuntu One should sync them between Ubuntu and Windows.

However, unfortunatly the Ubuntu one for Windows is english only, so if you do have a german Ubuntu installation, Ubuntu one will add a "docuemts" folder, and will not sync to the german "Dokumente" folder.


After upgrade to Kubuntu 18.04, System wakes up immediately after suspend. Bug?

Got it!
My USB wifi dongle seemed to wake my system up.
Step 1: check what is allowed to wake up your system:
Open a terminal:
sudo nano /proc/acpi/wakeup

Step 2: understand the results:

The list shows what device can awake your computer.
Here: EHC1 - EHC2 - XHC
Step 3: Block the device that wake up your computer:
Disable EHC1 in your terminal with:
echo EHC1 | sudo tee /proc/acpi/wakeup

Suspend your computer. If it still awakes, try
echo EHC2 | sudo tee /proc/acpi/wakeup

Note: EHC2 instead of EHC1. You can also try with XHC)
Note: above command is a kind of toggle. If you use it 2 times in a row, it will turn off EHC1, then turn it back on
Step 4: Confirm it worked
Here, it was EHC2 that woke up my computer (my USB wifi dongle). Now, it's disabled, it cannot awake my computer, and it stays suspended.


Snapcraft: autoreconf: 'configure.ac' or 'configure.in' is required

The autotools plugin, which is specified in your snapcraft.yaml is needed for the ./configure && make && sudo make install kind of software. (You can check the output of snapcraft help autotools to get an idea what it does, what its features are and what it expects.)

Looking at the contents of vokoscreen-2.5.0.tar.gz, it likely won't need the autotools plugin to build:

daniel@daydream:/tmp$ tar xfvz vokoscreen-2.5.0.tar.gz
./vokoscreen.run
daniel@daydream:/tmp$ file vokoscreen.run
vokoscreen.run: POSIX shell script executable (binary data)
daniel@daydream:/tmp$

The tarball contains only one executable, which looks like it's self-extracting. As far as I know there's no plugin for snapcraft which takes care of that yet, so you might want to write your own plugin. It should be just a couple of lines of python.

Update: Looking at https://codeload.github.com/vkohaupt/vokoscreen/tar.gz/2.5.0 you could also just build it from source using the qmake plugin.


Where to find information sources about the APT system?

To answer your numbered questions,

There is a comprehensive article on this at the Debian wiki.
Covered in 1.
Packages are split into different 'components' depending on their license and support like so:

Main - Officially supported software.
Restricted - Supported software that is not available under a completely free license.
Universe - Community maintained software, i.e. not officially supported software.
Multiverse - Software that is not free.

The exact license for each package is different and you should check individually.
Listed here: http://en.wikipedia.org/wiki/Advanced_Packaging_Tool#Front-ends

The following is an excerpt from the above:

Synaptic Package Manager, a GTK+ graphical user interface
Ubuntu Software Center, a GTK+ graphical user interface replacement for Synaptic
aptitude, a versatile alternative to dselect
KPackage, part of KDE
Adept Package Manager, a graphical user interface for KDE (deb, rpm, bsd)
PackageKit, a freedesktop.org frontend.
GDebi, a GTK-based tool sponsored for Ubuntu. (There is also a Qt version, available in the Ubuntu repositories a gdebi-kde.)


What worked for me:
sudo apt install calendarserver postgresql
sudo -u postgres createuser caldavd --no-createdb --no-createrole --no-superuser
sudo -u postgres createdb --owner=caldavd caldav
sudo -u caldavd psql -f /usr/lib/python2.7/dist-packages/txdav/common/datastore/sql_schema/current.sql caldav

Edit /etc/default/calendarserver  uncomment start_calendar_server=yes
reboot
For proper production mode: you need to edit the /etc/caldavd/caldavd.plist and enable https and point to a proper directory.
You want to have ext4 file system for the extended attributes
YMMV
There's a complete writeup on the steps


DiogenesList is a nice command-line clone of Snap2HTML. You simply download the python script and run the command as such in the terminal:

python diogeneslist.py /directory/you/want/to/scan nameofoutputfile

It will create a file named nameofoutputfile.html in your current directory that looks just like the file created by Snap2HTML.


Clamav: "WARNING: Can't read main.cvd header from db.local.clamav.net"

In fact, everything is normal. There's no problem

Because now ClamAV has got a daemon. The daemon does the updates. So if we want to do updates manually, we need to stop the daemon first.

 $ tail /var/log/clamav/freshclam.log
 Thu Nov 10 19:55:59 2016 -> WARNING: Can't query current.cvd.clamav.net
 Thu Nov 10 19:55:59 2016 -> WARNING: Invalid DNS reply. Falling back to HTTP mode.
 Thu Nov 10 19:55:59 2016 -> Reading CVD header (main.cvd): Thu Nov 10 19:55:59 2016 -> WARNING: Can't get information about db.local.clamav.net:   Temporary failure in name resolution
 Thu Nov 10 19:55:59 2016 -> WARNING: Can't read main.cvd header from db.local.clamav.net (IP: )
 Thu Nov 10 19:55:59 2016 -> Trying again in 5 secs...
 Thu Nov 10 19:56:04 2016 -> ClamAV update process started at Thu Nov 10 19:56:04 2016
 Thu Nov 10 19:56:04 2016 -> main.cvd is up to date (version: 57, sigs: 4218790, f-level: 60, builder: amishhammer)
 Thu Nov 10 19:56:04 2016 -> daily.cld is up to date (version: 22511, sigs: 853831, f-level: 63, builder: neo)
 Thu Nov 10 19:56:04 2016 -> bytecode.cld is up to date (version: 283, sigs: 53, f-level: 63, builder: neo)
 Thu Nov 10 19:56:04 2016 -> --------------------------------------

 $ sudo service clamav-freshclam stop
 $ sudo freshclam
 ClamAV update process started at Thu Nov 10 20:20:26 2016
 main.cvd is up to date (version: 57, sigs: 4218790, f-level: 60,  builder: amishhammer)
 daily.cld is up to date (version: 22511, sigs: 853831, f-level: 63, builder: neo)
 bytecode.cld is up to date (version: 283, sigs: 53, f-level: 63, builder: neo)

 $ tail /var/log/clamav/freshclam.log
 Thu Nov 10 19:56:04 2016 -> main.cvd is up to date (version: 57, sigs: 4218790, f-level: 60, builder: amishhammer)
 Thu Nov 10 19:56:04 2016 -> daily.cld is up to date (version: 22511, sigs: 853831, f-level: 63, builder: neo)
 Thu Nov 10 19:56:04 2016 -> bytecode.cld is up to date (version: 283, sigs: 53, f-level: 63, builder: neo)
 Thu Nov 10 19:56:04 2016 -> --------------------------------------
 Thu Nov 10 20:18:57 2016 -> Update process terminated
 Thu Nov 10 20:20:26 2016 -> --------------------------------------
 Thu Nov 10 20:20:26 2016 -> ClamAV update process started at Thu Nov 10 20:20:26 2016
 Thu Nov 10 20:20:26 2016 -> main.cvd is up to date (version: 57, sigs: 4218790, f-level: 60, builder: amishhammer)
 Thu Nov 10 20:20:26 2016 -> daily.cld is up to date (version: 22511, sigs: 853831, f-level: 63, builder: neo)
 Thu Nov 10 20:20:26 2016 -> bytecode.cld is up to date (version: 283, sigs: 53, f-level: 63, builder: neo)

 $ sudo service clamav-freshclam start


The problem was causes by the Volume Control configuration. The wrong audio profile was selected.

To clarify:

In the System settings sound pane, on the output tab, I have multiple outputs. (Digital, and analogue and Headphones).

I had the wrong one selected, and changed it so it now works.


Network Connections - Wired tab - edit button greyed out

This is on a desktop 13.04 now (but I did it in my first installation around 11.04, upgraded and never changed since...). I did not change any configuration file by hand.

I clicked on the network manager and selected "Network settings". Choose the wired connection (I remember there was a glitch in which you have to change the name of it, it didn't work with the default one). Then select the connection as system one (so that it connects without the need to login):

and then in IPv4 settings configuring it as a static IP.

I hope it still works...

(PS it's the same system, I have rotating backgrounds...)


Try to check if fans are working correctly!

If fans are working correctly then open system monitor application from the start menu and check that how much percentage resources are being used by the Operating System.


Wine no longer works after upgrading to 18.04

You can download LibPNG 1.2 packages manually from Ubuntu 16.04 LTS repository and install them with:

cd ~/Downloads
wget http://security.ubuntu.com/ubuntu/pool/main/libp/libpng/libpng12-0_1.2.54-1ubuntu1.1_amd64.deb
wget http://security.ubuntu.com/ubuntu/pool/main/libp/libpng/libpng12-0_1.2.54-1ubuntu1.1_i386.deb

sudo apt-get install ./libpng12-*.deb


How can I install vcrun2008 using Winetricks?

You can add vcrun2008, or any other Windows component or .dll, using Winetricks.

Open Winetricks
Select the profile that you want to add the .dll to (e.g. the default)
Select "Install a Windows DLL or component"; click OK
Select the component(s) you want installed; click OK
Follow the handy dialog boxes

Good luck!


List hidden files but exclude directories.

ls -ld .?* |grep -v ^d

This lists all dot files but no directories...


Ubuntu freezes after Android MTP connected

In my case, solution was:

Android MM:
Settings->Advanced settings/options -> Debug options ->Verify applications - USB (disable)

The system will freeze/crash if this option is enabled.


Moving windows against desktop background leaves a persistent trail which can only be cleared by going into activity overview

I was having the same issue which seems like it was being caused by trying to set my monitor positioning using xrandr. Once I removed my startup script and renamed the .config file in my home directory so that a new one was created after logging back in, everything seems to be working like it should.


Extremely slow connection with a Broadcom BCM4313 wireless card

Please do:

sudo apt-get purge --remove bcmwl-kernel-source
sudo modprobe -rv wl
sudo modprobe -v brcmsmac

if there are any errors complete the rest of the commands anyway.

We may have to unblacklist some modules if the purge command does not do it for us.


How to set default style for libreOffice Object Formula?

type "fn" in the beginning of the paragraph + press {F3} and you will have everything formatted like a charm.


Steam games crashes randomly on Ubuntu 17.10 (GNOME)

This sounds like there is a problem with a PCI Express device not properly communicating with the Root port. I suspect this may be a kernel issue. You could try using a different kernel, e.g. with: https://wiki.ubuntu.com/Kernel/KernelPPA

PS: This was meant as a reply to your comment... got the wrong field. Can you maybe update the original question, if this solution is was useful?


What is Logjam attack and how to protect Ubuntu against it?

Update your browser when you can. Here you can check if your browser is affected: https://weakdh.org/

Google is aware of this and is working on a fix for their browsers. For firefox there is a notice on their forums.  From both you can expect updates fairly quickly.

Regarding this bug:

  The attack allows a man-in-the-middle to downgrade security of connections to a lower level of encryption — 512 bit — which can be read and attacked with relative ease.

If you do use encryption yourself use something better than 512 bits. If the encryption is done with a browser (https) you will need to wait for the maintainer of that browser to create a new release.

The website above also has a couple of pointers. The most important one if you are using apache:

  Disable support for SSLv2 and SSLv3 and enable support for TLS, explicitly allow/disallow specific ciphers in the given order:

    SSLProtocol             all -SSLv2 -SSLv3

    SSLCipherSuite          ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-     GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA

    SSLHonorCipherOrder     on

DH Parameters — Use the strong DH parameters generated earlier :

SSLOpenSSLConfCmd DHParameters "{path to dhparams.pem}"

They have more on MS IIS, nginx and tomcat.

On security.stackexchange.com there is also a topic on this: What is Logjam and how do I prevent it? with some details about this.


how to Send to Kindle for Mozilla Firefox?

Taken directly from the link you provided:

  Not compatible with Firefox Quantum

Firefox Quantum is any version higher and including Firefox 57.

  Perhaps there's a compatibility issue?

The add-on in question isn’t compatible with Firefox 59 on any operating system.  You would have to use the long term support version to use this particular add-on.


Set Default music player to Banshee, yet it's still Rythmbox?

To completly remove an application you can run:

sudo apt-get purge packagename


Ubuntu 16.04 not booting from USB stick: gfxboot.c32: not a COM32R image

This is bug 1325801.  The wrong version of syslinux gets used, the one from the running system instead of the one from the ISO.  If you have a runnable 16.04 live system, you can use it to make another one with Startup Disk Creator, or just use mkusb on the 14.04 system, which will give you a safer way to use dd, which works too.


Installed KDE4.8 on Ubuntu and it messed up browser's fonts

Actually, that messed up my terminal font... I ended up making .fonts.conf look like:

<?xml version="1.0"?><!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
 <match target="font">
  <edit mode="assign" name="rgba">
   <const>none</const>
  </edit>
 </match>
 <match target="font">
  <edit mode="assign" name="hinting">
   <bool>true</bool>
  </edit>
 </match>
 <match target="font">
  <edit mode="assign" name="hintstyle">
   <const>hintslight</const>
  </edit>
 </match>
 <match target="font">
  <edit mode="assign" name="antialias">
   <bool>true</bool>
  </edit>
 </match>
</fontconfig>


Ext4 file system format drive does not show in Windows 8

You can install a Windows filesystem driver to read Ext2/3/4 filesystems: Ext2Fsd. This message you're seeing is because Windows does not recognize these filesystems and offers you to reformat it using a Windows-native filesystem (NTFS/FAT32).

See Ext2 File System Driver for Windows (sourceforge.net) and Ext2Fsd Project for more information on how to install it. While the name suggests it's for Ext2 only, it works for 3 and 4 as well.

However, for sharing files between the two operating systems in a dual boot configuration, I would prefer to use either NTFS or FAT32 on that partition. But then it won't be possible to use this partition for Ubuntu system file (boot drive) or home directory, because of permission features it is lacking.


General security questions switching from W10

Impossible to say what these unencrypted partitions are if you don't show us, but probably some boot partition, or additional partitions that are not / or /home and are not automatically encrypted. The latter you can always encrypt later on however.
As to the swap space, from Ubuntu 18.04 on swap is no longer a separate partition, but a file stored on the root filesystem, so with FDE it would be encrypted as well.


Investigate the possibility to use a restricted shell for the users. Together with modifying PATH to specify a directory wich contains only commands that you allow your users to run (you may create such a directory and just put symlinks or hardlinks to the original commands there) it may give you what you need.


Make DNS follow configuration from Network Manager in 19.04

I've found a solution.

First, disable systemd-resolve:

sudo systemctl disable systemd-resolved.service
sudo systemctl stop systemd-resolved

Remove the symlink for resolv.conf and create a file:

rm -rf /etc/resolv.conf
touch /etc/resolv.conf
chmod a+rw /etc/resolv.conf

Now change the configuration file for Network Manager to restore the expected result: vi /etc/NetworkManager/NetworkManager.conf:

[main]
plugins=ifupdown,keyfile
# add this line
dns=default

and leave the rest of the file as is. Restart Network Manager:

sudo /etc/init.d/network-manager restart

and configure your preferred DNS servers. Done!


There may be a problem with the drivers Ubuntu's using if it's only giving you this issue in the Ubuntu installation. If the laptop has an ethernet port and you have a cable, try hooking that up temporarily and typing sudo apt-get update && sudo apt-get upgrade into a terminal and see if any package updates come up. These might hold a solution.


There should be a hidden directory in your home folder ~/.config/inkscape, try moving that inkscape directory elsewhere and then try restarting Inkscape. If that does not work you can bring back that inscape directory under .config again.


Ubuntu Installation - "ubuntu-18.04.1-desktop-amd64.iso: cannot execute binary file" on Mac

This is not an answer but I don't have enough reputation for comment:

You can not execute an iso file like that. Follow the instructions on this site to create a bootable Ubuntu USB from the iso file:

https://tutorials.ubuntu.com/tutorial/tutorial-create-a-usb-stick-on-macos#0


I/O or faulty hard disk error during ubuntu installation

If your installation is getting all the way to the end then your disk isn't bad. There's something about that partition layout that is likely spooking the installation of grub.

That's an awfully complex partition layout on your first disk so I'm not surprised that you're having problems.

I would suggest that you re-configure the installation to install grub to a partition, and not the Master Boot Record (MBR). This should be available in the standard image installer, if not, download the alternative installer image which gives you much more control over the installation process.


apt-get install openjdk-7-jdk doesn't install javac. Why?

The proper Debian/Ubuntu way to configure which javac is pointed to by /usr/bin/javac is to use the update-alternatives command. You can do it interactively, and select from a list of available options:

sudo update-alternatives --config javac

Or you can specify which option you want on the command-line:

sudo update-alternatives --set javac /usr/lib/jvm/java-7-openjdk/bin/javac

Because of the way it stores the information, using update-alternatives is not exactly equivalent (but instead is considered preferable) to manually making /usr/bin/java a symbolic link to your javac of choice. See man update-alternatives for more information about this.

If update-alternatives doesn't work, then run this command and try again:

sudo ln -s /etc/alternatives/javac /usr/bin/javac


Getting just Windows 8 (no dual boot) back from Ubuntu?

Check partitions. Boot your linux live cd/bootable usb, press "ALT+F2", write "gparted", then check how many paritions do you see?

If there are 2 partitions (maybe 3 or 4, because os swap. Windows has as well) - you can recover your windows partition somehow, but if you see only one linux partition and it's swap logical partition, you are mucked up! (Sorry moderators, but what does 'mucked up' mean? o.O )

That means put Windows 8 cd and install it


3 Monitors, 2 graphics card (NVIDIA, Intel) on Ubuntu 15.04

I have 3 monitors, two DELL and one smaller HP L1750  and two video cards running OK:

  01:00.0 VGA compatible controller: NVIDIA Corporation GF108GL [Quadro 600] (rev a1)
   00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 Processor Family Integrated Graphics Controller (rev 09)

My three monitors:

xrandr --query

Screen 0: minimum 8 x 8, current 3200 x 1200, maximum 16384 x 16384

DVI-I-0 connected primary 1600x1200+1280+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0
   1152x864       75.0
   1024x768       75.0     60.0
   800x600        75.0     60.3
   640x480        75.0     59.9

DP-0 connected 1600x1200+1600+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0
   1152x864       75.0
   1024x768       75.0     60.0
   800x600        75.0     60.3
   640x480        75.0     59.9

DP-1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)

VGA1 connected 1280x1024+0+176 (normal left inverted right x axis y axis) 340mm x 270mm
   1280x1024      60.0 +   75.0*
   1152x864       75.0
   1024x768       75.1     70.1     60.0
   832x624        74.6
   800x600        72.2     75.0     60.3
   640x480        75.0     72.8     60.0
   720x400        70.1

VIRTUAL1 disconnected (normal left inverted right x axis y axis)

  1280x1024 (0x327)  108.0MHz
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock   64.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   60.0Hz
  1280x1024 (0x326)  135.0MHz
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock   80.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   75.0Hz
  1152x864 (0x328)  108.0MHz
        h: width  1152 start 1216 end 1344 total 1600 skew    0 clock   67.5KHz
        v: height  864 start  865 end  868 total  900           clock   75.0Hz
  1024x768 (0x32a)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x32b)   49.5MHz
        h: width   800 start  816 end  896 total 1056 skew    0 clock   46.9KHz
        v: height  600 start  601 end  604 total  625           clock   75.0Hz
  800x600 (0x32c)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x32d)   31.5MHz
        h: width   640 start  656 end  720 total  840 skew    0 clock   37.5KHz
        v: height  480 start  481 end  484 total  500           clock   75.0Hz

From the first moment three monitords had been working ok, but with a little problem: Always i must to reconfigure the monitors configuration at starting ubuntu... everyday!

But is the first ubuntu in witch the 3 monitors configuration has runed without modifying configuration files. All has been done with the default Ubuntu monitor configuration tool.

Ah, this is that I had to do in Ubuntu 14.10  to have 3 monitors running (I had problems Ubuntu to detect my third monitor:

sudo xrandr --newmode "1280x1024_60.00" 135.00  1280 1296 1440 1688  1024 1025 1028 1066 +Hsync +Vsync
sudo xrandr --addmode VGA1 1280x1024_60.00
sudo xrandr --output VGA1 --mode 1280x1024_60.00


Adhoc connection between Ubuntu to Ubuntu

Look for essid:

sudo iwlist wlan0 scan | grep -i 'essid'

release the ip:

sudo dhclient -r wlan0

connect to NEWNET:

sudo iwlist wlan0 essid NEWNET

Assign IP:

sudo dhclient wlan0

Check results:

dmesg

Also consider looking at the results of sudo iwlist wlan0 scan to see if there is any useful information in regards to network masks, radio channels, or the like that might not be matching up.


Unable to install software on running VMware in Windows 10

Check whether the app is available for your version. See here.
Just type in top in the terminal and you will see the information you need.
However if you want htop then follow ahead.
First run sudo apt update && sudo apt upgrade to keep the repository link up to date and update the apps if any.
Then run sudo apt install htop. This should just work fine, however if this is giving an error (as you said), try using the snap version of this package. Install the snap version using sudo snap install htop. However to use use snap you will need to install snap. To do this run sudo apt update && sudo apt install snapd.
You could also try gnome-system-monitor which is a GUI based application. Just open you app drawer with super + A, and search for monitor and it should just pop right up. However you could install manually with sudo apt install gnome-system-monitor.
To clear the source.list you will need sudo rights. You could run sudo nautilus in terminal and then the file explorer will open with sudo rights, but not all files are shown in it. So you could try the rm command from the terminal with sudo right to remove any file. Eg. to remove a file on desktop named temp.txt, I will use sudo rm -rf /home/desktop/temp.txt. -rf is used to force remove. Syntax is sudo rm -rf /filepath/filename to remove a file name filename at filepath location.


I also posted this question to Ubuntu Forums where it was answered by moderator Frogs hair. His first solution (which had no appreciable effect, but is included here for completeness) was

sudo apt-get update
sudo apt-get install gnome-session-flashback

His second solution (which worked) was one which he apparently found here on Ask Ubuntu:

cp /usr/share/applications/gnome-panel.desktop ~/.config/autostart/

He did not provide a link to the post, and says the post included no explanation, so I would be interested if anyone can tell me what this command did for me and why.


Ubuntu is not loaded after full disk encryption

Finally I've resolved that issue. Unfortunately I can't answer what was the root cause. I took another USB drive and performed all steps again from the link in my first post. It works correct now. So it looks like my first USB drive is damaged.


SSH: "You must specify a subsystem to invoke."

If you would like to run a non local script on a remote server, you may have to use the following syntax:

/usr/bin/ssh livehostusername@host 'bash /dev/stdin' < local_script.sh

If you would like simply to run a command on a remote server, you may use the following systax

/usr/bin/ssh livehostusername@host /full_path/local_script.sh


Upgrade to 16.04. php7 not working in browser

Just like before, you have to install PHP for Apache.

From the Server Guide:

sudo apt install php libapache2-mod-php

That command will install PHP and the Apache 2 PHP module.  Simply configure Apache as before (sudo a2enmod php7.0, I think, will turn on the module).

Your mbstring issue is similar - you need to install that extension:

sudo apt install php7.0-mbstring

For other missing modules there will be similar things to have to install as well.


xbindkeys + xvkbd works, but xbindkeys + xdotool fails

I found the following string to work for me (copying operation as an example):

"xset r off; xdotool key --clearmodifiers 'Control_L+c'; xset r on"
Control + Insert + Release

Based on the accepted answer for this thread.


You need to, at least, change the permissions for /home/myuser:

   $ sudo chown myuser:myuser /home/myuser
   $ sudo chmod 755 /home/myuser

And see if that fixes it. It's hard to know what you did and how to completely undo it, but that should help.


How to remove GNOME Shell from Ubuntu 20.04 LTS to install other desktop environment from scratch?

The single long command for GNOME Shell removal is below
sudo apt purge adwaita-icon-theme gedit-common gir1.2-gdm-1.0 \
gir1.2-gnomebluetooth-1.0 gir1.2-gnomedesktop-3.0 gir1.2-goa-1.0 \
gnome-accessibility-themes gnome-bluetooth gnome-calculator gnome-calendar \
gnome-characters gnome-control-center gnome-control-center-data \
gnome-control-center-faces gnome-desktop3-data \
gnome-font-viewer gnome-getting-started-docs gnome-getting-started-docs-ru \
gnome-initial-setup gnome-keyring gnome-keyring-pkcs11 gnome-logs \
gnome-mahjongg gnome-menus gnome-mines gnome-online-accounts \
gnome-power-manager gnome-screenshot gnome-session-bin gnome-session-canberra \
gnome-session-common gnome-settings-daemon gnome-settings-daemon-common \
gnome-shell gnome-shell-common gnome-shell-extension-appindicator \
gnome-shell-extension-desktop-icons gnome-shell-extension-ubuntu-dock \
gnome-startup-applications gnome-sudoku gnome-system-monitor gnome-terminal \
gnome-terminal-data gnome-themes-extra gnome-themes-extra-data gnome-todo \
gnome-todo-common gnome-user-docs gnome-user-docs-ru gnome-video-effects \
language-pack-gnome-en language-pack-gnome-en-base language-pack-gnome-ru \
language-pack-gnome-ru-base language-selector-gnome libgail18 libgail18 \
libgail-common libgail-common libgnome-autoar-0-0 libgnome-bluetooth13 \
libgnome-desktop-3-19 libgnome-games-support-1-3 libgnome-games-support-common \
libgnomekbd8 libgnomekbd-common libgnome-menu-3-0 libgnome-todo libgoa-1.0-0b \
libgoa-1.0-common libpam-gnome-keyring libsoup-gnome2.4-1 libsoup-gnome2.4-1 \
nautilus-extension-gnome-terminal pinentry-gnome3 yaru-theme-gnome-shell

sudo apt autopurge

Note: if one have previously installed Vanilla GNOME desktop manually by sudo apt install vanilla-gnome-desktop and/or Ubuntu GNOME desktop by sudo apt install ubuntu-gnome-desktop and/or GNOME FlashBack by sudo apt install gnome-flashback gnome-panel and/or full GNOME by sudo apt install gnome - one have to execute extra removal commands below:
sudo apt purge adwaita-icon-theme geogebra-gnome gir1.2-gtd-1.0 \
gnome-accessibility-profiles gnome-applets-data gnome-audio gnome-backgrounds \
gnome-cards-data gnome-common gnome-desktop-testing gnome-dvb-daemon \
gnome-exe-thumbnailer gnome-extra-icons gnome-flashback-common \
gnome-humility-icon-theme gnome-hwp-support gnome-icon-theme \
gnome-icon-theme-gartoon gnome-icon-theme-gartoon-redux \
gnome-icon-theme-gperfection2 gnome-icon-theme-nuovo gnome-icon-theme-suede \
gnome-icon-theme-yasis gnome-mime-data gnome-nds-thumbnailer \
gnome-packagekit-data gnome-panel-control gnome-panel-data \
gnome-pkg-tools gnome-recipes-data gnome-remote-desktop gnome-settings-daemon-dev \
gnome-shell-pomodoro-data gnome-software-common gnome-software-doc \
gnome-theme-gilouche gnome-video-effects-extra gnome-video-effects-frei0r \
guile-gnome2-dev guile-gnome2-glib libgnome-autoar-doc libgnomecanvas2-common \
libgnomecanvas2-doc libgnomecanvasmm-2.6-doc libgnome-panel-doc libgnome-todo-dev \
libopenrawgnome7:amd64 libopenrawgnome-dev libreoffice-gnome libxine2-gnome:amd64 \
nautilus-sendto pidgin-gnome-keyring plymouth-theme-ubuntu-gnome-logo \
plymouth-theme-ubuntu-gnome-text ubuntu-gnome-wallpapers \
ubuntu-gnome-wallpapers-trusty ubuntu-gnome-wallpapers-utopic \
ubuntu-gnome-wallpapers-xenial ubuntu-gnome-wallpapers-yakkety

sudo apt autopurge

Then one can install any desktop environment of interest with commands like:

Cinnamon - sudo apt install cinnamon-desktop-environment
KDE as in Kubuntu - sudo apt install kubuntu-desktop^
MATE as in Ubuntu MATE - sudo apt install ubuntu-mate-desktop^
Unity - sudo apt install ubuntu-unity-desktop
Xfce as in Xubuntu - sudo apt install xubuntu-desktop^

then reboot, select newly installed desktop session and login to it.

Note: this method is applicable for Ubuntu 20.10 and 21.04 too.


gufw - rules listed in red and green. What do these colors mean

GUFW uses colors to quickly identify what type of rule you are looking at.

Green = Deny
Red = Allow
Blue = Reject
Yellow = Limit
Black = No rule set

Note: These rules are just some default ones I stuck in here for the purpose of the screenshot, and are not meant to be seen as recommendations.


Lightweight C/C++ editor with code completion and debugging

You could give a try to the default text editor, GEdit (it looks pretty decent on Xfce with a gtk theme). The gedit-plugins package contains, among many others others:

Bookmarks
Bracket Completion
Code block comment/uncomment
File Browser
Session persistence
Embedded Terminal

To these you may add a few additional plugins:

FuncBrowser
Autocomplete
MakeAndRun

As for debugging there is nothing but you can use gdb within the integrated terminal.

And of course, you'll have the Oblivion theme, the best coding theme ever produced.

Further reading:

gedit: Add Python / C++ Autocomplete Support

How to convert gEdit to gEdit++


How do you set up SSL certificates for additional ports in Apache?

You make modifications in apache's /etc/apache2/ports.conf to inform apache to listen on these different ports:

Listen 8080
<IfModule ssl_module>
        Listen 446
</IfModule>

The steps would be:

Create your SSL certificates:

Make directory to add certificates:

mkdir -p /etc/apache2/ssl/example.com

Create a self signed certificate:

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/apache2/ssl/example.com/apache.key –out /etc/apache2/ssl/example.com/apache.crt

Enable the ssl module with: sudo a2enmod ssl
Make entries in your Virtualhost files ( called example.conf ), with sudo nano /etc/apache2/sites-available/example.conf

<VirtualHost *:8080>
    ServerAdmin webmaster@localhost
    ServerName example.com
    DocumentRoot /var/www/html

</VirtualHost>

<IfModule mod_ssl.c>
<VirtualHost *:446>

    ServerAdmin webmaster@localhost
    ServerName example.com
    DocumentRoot /var/www/html

    #   SSL Engine Switch:
    #   Enable/Disable SSL for this virtual host.
    SSLEngine on

    #   A self-signed (snakeoil) certificate can be created by installing
    #   the ssl-cert package. See
    #   /usr/share/doc/apache2.2-common/README.Debian.gz for more info.
    #   If both key and certificate are stored in the same file, only the
    #   SSLCertificateFile directive is needed.
    SSLCertificateFile /etc/apache2/ssl/example.com/apache.crt
    SSLCertificateKeyFile /etc/apache2/ssl/example.com/apache.key
</VirtualHost>

</IfModule>

Tell apache to listen in the new ports by adding the ports to /etc/apache2/ports.conf file:

Listen 8080
<IfModule ssl_module>
    Listen 446
</IfModule>

<IfModule mod_gnutls.c>
    Listen 446
</IfModule>

This tells apache to listen for SSL traffic on port 446 as against 443

Enable the config files:

sudo a2ensite example

Restart apache:

sudo systemctl restart apache2


Cloning full-disc-encrypted system unencryptedly onto new disc

It turns out the whole thing is easier than I thought. Motivated by @Xen2050's comments, I was able to essentially just rsync the whole system onto a fresh install:

Boot with a live stick
Install a fresh Ubuntu onto the new disc (using a separate efi boot partition)
Mount the new Ubuntu's root partition to /mnt/new-root
Decrypt the old system via cryptsetup luksOpen /dev/sdXY crypt1
Mount the old root partition by mount /dev/mapper/ubuntu--vg-root /mnt/old-root
Copy everything: rsync -aAXv --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} /mnt/old-root /mnt/new-root
Edit the fstab in /mnt/new-root/etc/fstab to contain the UUIDs of the partitions on the new disc (can be obtained via gparted)

And surprisingly, that's all. Restart, and you can boot from the new disc, with everything the same as before (just without encryption and faster).


On booting ubuntu installer from PD, it shows up a black screen with error codes

To load Ubuntu installation from a USB drive, you need to have UEFI enabled (that is the default for the newest computers). If you have it disabled when trying to use the Ubuntu Live media, while it'd still most likely work, you will lose functionality.

The SecureBoot option may or may not work, depending on your computer. If SecureBoot enabled failed, just change that to disabled.

If the Try Ubuntu without installing option fails to boot

Some computer's hardware may have problems with some of the Desktop drivers. You can fix this by typing e at the Try Ubuntu without installing option from the initial black screen menu. Then replace the words quiet splash with nomodeset. Then hit F10 to boot.


How to dual boot install Ubuntu 15 with Windows 10: No other operating system recognized

Maybee you didn't shutdown your computer completely before installing your Windows 10?

You have to disable quick boot and you should shutdown your computer completely before you proceed with the installation.

http://www.tenforums.com/tutorials/7418-shut-down-computer-windows-10-a.html

You should install your bootloader into mbr of your system disc (sda) and not under the root partition. If it is not installed in mbr, grub2 will not recognize the operating systems on your hard disk.

Another way which might eventually help you to solve the problem is to boot into your Windows 10 and install Easy-BCD 2.3. It will search for the operating systems on the hard drive and you should be able to choose which one to boot on Windows 10 start - if there is any Ubuntu boot loader installed anywhere on the hard drive (like boot loader in the root partition).

Fast boot should be / stay disabled.


How to delete folders that have n or fewer files in them?

One way would be to use find's -exec action to execute a custom test of the number of files.

One could use a second find command along with wc to find and count files within each directory, but probably a better option would be to shell globbing to slurp the filenames into an array, and then return a logical value indicating whether the size of the array is less than the threshold i.e.

files=( dir/* ); ((${#files[@]} < 10))

Putting it all together, we should be able to list all subdirectories with fewer than 10 files (including sub-subdirectories) using

find . -depth -type d ! -name '.' -exec bash -c '
  shopt -s nullglob; files=( "$1"/* ); ((${#files[@]} < ${2:-10}))
  ' bash {} 10 \; -print0 | xargs -0

(you can adjust the number 10 after the bash {} for different thresholds - the ${2:-10} parameter expansion makes it default to 10 files if no second argument is given). For example, given

$ tree .
.
├── bar
│   ├── file1
│   ├── file2
│   ├── file3
│   ├── file4
│   ├── file5
│   ├── file6
│   ├── file7
│   ├── file8
│   ├── file9
│   └── other file
├── baz
│   ├── other file
│   └── subdir
└── foo
    └── somefile

4 directories, 12 files

then

find . -depth -type d ! -name '.' -exec bash -c '
  shopt -s nullglob; files=( "$1"/* ); ((${#files[@]} < "${2:-10}"))
  ' bash {} 10 \; -print0 | xargs -0
./foo ./baz/subdir ./baz

If that appears to be doing the right thing you can actually remove them by adding rm -rf but please be very careful with this - remember there is no 'undo'

find . -depth -type d ! -name '.' -exec bash -c '
  shopt -s nullglob; files=( "$1"/* ); ((${#files[@]} < ${2:-10}))
' bash {} 10 \; -print0 | xargs -0 rm -rf

(The xargs could be eliminated by using another -exec action to run rm more directly, but the formulation above makes it easy to generalize - print, stat, remove or whatever.)

Note this will act recursively i.e. a directory that initially has more than n files including subdirectories may be removed as a result of some of those subdirectories themselves getting removed as find backs up the directory tree - the current directory is explicitly protected from possible deletion by the ! -name '.' test.

If you don't need it to act recursively, you can simply loop over directories and perform the same file count and test logic e.g. to remove all first-level directories containing fewer than 10 files in the current directory

shopt -s nullglob
for d in */; do
  files=( "$d"/* )
  ((${#files[@]} < 10)) && echo rm -rf -- "$d"
done


With the following command you can obtain a list of installed packages, classified by priority:

dpkg-query -Wf '${Package;-40}${Priority}\n' | sort -b -k2,2 -k1,1

A description of priorities is given in the Debian Policy Manual.

In my installation I obtain the following (I only show required, important and standard packages):

apt                                     important
aptitude                                important
apt-utils                               important
bsdmainutils                            important
cron                                    important
debconf-i18n                            important
dmidecode                               important
gnupg                                   important
gpgv                                    important
groff-base                              important
info                                    important
install-info                            important
iptables                                important
iputils-ping                            important
isc-dhcp-client                         important
isc-dhcp-common                         important
libapt-inst1.3                          important
libapt-pkg4.11                          important
libboost-iostreams1.46.1                important
libcwidget3                             important
libept1                                 important
libgdbm3                                important
libgdbm3                                important
libgudev-1.0-0                          important
libnewt0.52                             important
libpcre3                                important
libpipeline1                            important
libpopt0                                important
libreadline6                            important
libssl1.0.0                             important
libsysfs2                               important
libusb-0.1-4                            important
libxapian22                             important
logrotate                               important
man-db                                  important
manpages                                important
medibuntu-keyring                       important
nano                                    important
netbase                                 important
net-tools                               important
python                                  important
readline-common                         important
rsyslog                                 important
ubuntu-extras-keyring                   important
ubuntu-keyring                          important
vim-common                              important
vim-tiny                                important
wget                                    important
whiptail                                important
adduser                                 required
base-files                              required
base-passwd                             required
bash                                    required
bsdutils                                required
busybox-initramfs                       required
coreutils                               required
cpio                                    required
dash                                    required
debconf                                 required
debianutils                             required
diffutils                               required
dpkg                                    required
e2fslibs                                required
e2fsprogs                               required
findutils                               required
gcc-4.6-base                            required
gcc-4.6-base                            required
grep                                    required
gzip                                    required
hostname                                required
ifupdown                                required
initscripts                             required
insserv                                 required
iproute                                 required
klibc-utils                             required
libacl1                                 required
libacl1                                 required
libattr1                                required
libattr1                                required
libblkid1                               required
libbz2-1.0                              required
libc6                                   required
libc6                                   required
libc-bin                                required
libcomerr2                              required
libcomerr2                              required
libdb5.1                                required
libdbus-1-3                             required
libdevmapper1.02.1                      required
libdrm2                                 required
libdrm-intel1                           required
libdrm-nouveau1a                        required
libdrm-radeon1                          required
libffi6                                 required
libgcc1                                 required
libgcc1                                 required
libglib2.0-0                            required
libklibc                                required
liblocale-gettext-perl                  required
liblzma2                                required
libmount1                               required
libncurses5                             required
libncursesw5                            required
libnih1                                 required
libnih-dbus1                            required
libpam0g                                required
libpam-modules                          required
libpam-modules-bin                      required
libpam-runtime                          required
libpciaccess0                           required
libpcre3                                required
libplymouth2                            required
libpng12-0                              required
libselinux1                             required
libselinux1                             required
libslang2                               required
libss2                                  required
libssl1.0.0                             required
libstdc++6                              required
libstdc++6                              required
libtext-charwidth-perl                  required
libtext-iconv-perl                      required
libtext-wrapi18n-perl                   required
libtinfo5                               required
libudev0                                required
libuuid1                                required
libuuid1                                required
locales                                 required
login                                   required
lsb-base                                required
lzma                                    required
makedev                                 required
mawk                                    required
module-init-tools                       required
mount                                   required
mountall                                required
multiarch-support                       required
ncurses-base                            required
ncurses-bin                             required
passwd                                  required
perl-base                               required
plymouth                                required
procps                                  required
python2.7-minimal                       required
python-minimal                          required
sed                                     required
sensible-utils                          required
sysvinit-utils                          required
sysv-rc                                 required
tar                                     required
tzdata                                  required
udev                                    required
upstart                                 required
ureadahead                              required
util-linux                              required
xz-utils                                required
zlib1g                                  required
zlib1g                                  required
at                                      standard
bash-completion                         standard
bc                                      standard
bind9-host                              standard
dc                                      standard
dnsutils                                standard
file                                    standard
ftp                                     standard
gettext-base                            standard
less                                    standard
libbind9-60                             standard
libcap2                                 standard
libdb5.1                                standard
libdns69                                standard
libedit2                                standard
libevent-2.0-5                          standard
libgc1c2                                standard
libgcrypt11                             standard
libgcrypt11                             standard
libgnutls26                             standard
libgnutls26                             standard
libgpg-error0                           standard
libgpg-error0                           standard
libgpm2                                 standard
libgssapi-krb5-2                        standard
libgssapi-krb5-2                        standard
libidn11                                standard
libidn11                                standard
libisc62                                standard
libk5crypto3                            standard
libk5crypto3                            standard
libkeyutils1                            standard
libkeyutils1                            standard
libkrb5-3                               standard
libkrb5-3                               standard
libkrb5support0                         standard
libkrb5support0                         standard
libldap-2.4-2                           standard
libldap-2.4-2                           standard
liblockfile1                            standard
liblwres60                              standard
libmagic1                               standard
libpci3                                 standard
libsasl2-2                              standard
libsasl2-2                              standard
libsqlite3-0                            standard
libsqlite3-0                            standard
libtasn1-3                              standard
libtasn1-3                              standard
libxml2                                 standard
lsof                                    standard
m4                                      standard
make                                    standard
mime-support                            standard
mlocate                                 standard
openssh-client                          standard
patch                                   standard
pciutils                                standard
perl                                    standard
perl-modules                            standard
python-apt                              standard
python-central                          standard
telnet                                  standard
time                                    standard
ucf                                     standard
wamerican                               standard
whois                                   standard

The Base System is defined as a system containing only required and important packages.

Packages marked as standard are not strictly needed for a working system, but you can get into difficulties if you miss them.

So, to remove all unneeded packages (optional and extra), you can execute the following command:

sudo apt-get --simulate purge $(dpkg-query -Wf '${Package;-40}${Priority}\n' |
    awk '$2 ~ /optional|extra/ { print $1 }')

I added the --simulate option to be safe and see what apt says.

Strangely, it asks to remove also some required packages: e2fsprogs, util-linux, hostname and upstart, so it is necessary to reinstall these packages. I would download the packages in advance (apt-get download <packages>), to avoid network problems after.

Take also into account that for a working Wifi you can need some optional or extra package, removed in the above procedure.


Will GCC compiler or anything else update if I install Atom Editor?

Run sudo apt-cache show atom-amd64.deb to check your system to see if there are unmet dependencies which would be installed. Compare their versions to what you have now for each of those dependencies.


Why is this rsync + ssh cron job giving me 'Permission denied (publickey)' errors?

Since everything is working fine from the command line, the error Permission denied (publickey) means that the SSH part of rsync is using a different identity file than the specified username.

From Jan's comment on the original question, we can specify the identity file in the rsync command using -e 'ssh -i /path/to/identity.file' ....

Using the below command to start off with a fresh environment in cron and specifying the complete path to the file apparently solves the issue:

env -i sh -c "rsync -lrstRO --delete --exclude 'lost+found' -e 'ssh -i /home/tom/.ssh/backups-only' /Backups/auto-daily-backups/./ backups-only@XX.XX.XX.XX:/backups/desktop/"

I'm still really interested in this finding. It probably has to do with cron, the fact that it starts with minimal environment variables, and the ssh-agent. I'll be setting up the same scenario ina a couple of days to test it out and report back.


Install older version of firefox for SlimerJS

The best solution for same this error :

  Error: Platform version '5x.xx' is not compatible with  or  Gecko
  error: it seems /usr/bin/firefox is not compatible with SlimerJS.
  See Gecko version compatibility. If version is correct, launch
  slimerjs
  with --debug=true to see Firefox error message

is use old firefox version inside your updated firefox:

update SlimerJS and make sure this the latest version.
Download the mozilla firefox version 50 from :
https://ftp.mozilla.org/pub/firefox/releases/50.0/ and choose your OS and i386 or x64 and favorite lang for example i download https://ftp.mozilla.org/pub/firefox/releases/50.0/linux-x86_64/en-US/firefox-50.0.tar.bz2 for Ubuntu 16.04 64bit
then extract the downloaded file:

$ tar xvjf firefox-50.0.tar.bz2

for example i extract into /home/username/oldmozilla

set extracted directory to SLIMERJSLAUNCHER path:

$ export SLIMERJSLAUNCHER=/home/yourname/oldmozilla/firefox/firefox

  note: you must give firefox app not directory

run your js app simply ; )


Did you change pulseaudio settings? My players eat a lot of CPU if I crank pulseaudio frequency or resampling algorithm too high.


How can I execute command on startup (rc.local alternative) on Ubuntu 16.10

Intro

I think you should not create a new service as suggested in the link by George.
The rc-local.service already exists in systemd and the service file suggests that the rc.local, if it exists and is executable, gets pulled automatically into multi-user.target.
So no need to recreate or force something that is just done in another way by the systemd-rc-local-generator.

One solution

A quick solution (I don't know if that's the canonical way):

In a terminal do:

printf '%s\n' '#!/bin/bash' 'exit 0' | sudo tee -a /etc/rc.local
sudo chmod +x /etc/rc.local
sudo reboot

After that the rc.local will be called upon system startup. Insert what you like.

Background

If you do in a terminal:

sudo systemctl edit --full rc-local

You can see that the head comment contains lines such as:

# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.

This indicates, that in this system, if there is a file called /etc/rc.local which is executable, then it will be pulled into multi-user.target automatically. So you just create the according file (sudo touch...) and make it executable (sudo chmod +x ...).


Installed XFCE on Kubuntu, now getting duplicate lock screen login

It turned out that for some reason KDM was removed. To reinstall it:

sudo apt install kdm

If KDM is installed but disabled in favour of a different display manager, e. g. LightDM, you can reconfigure KDM as the default again:

sudo dpkg-reconfigure kdm


Which Webcam software provides live "fire effects"?


Install font packages for all the language charsets

Please have a look here
https://help.ubuntu.com/community/Fonts
you can install font packages listed here


Sharing folders through Nautilus refuses to work on one Ubuntu 14.04 machine

Here's the list of steps I've gone through to get sharing working on my machine.

1)  Install samba

sudo apt-get install samba

2) add myself to group sambashare (which is listed in /etc/group; most likely this is the root of your problem)

sudo usermod -a -G sambashare myusernamehere

3) reboot

4) Make sure ports 139 (netbios-ssn) and 445 (microsoft-ds) were open after installation and reboot with nmap (optional step, maybe skipped)

5) created a test folder in my home directory , with nautilus. Alternatively could have done same with mkdir ~/test. Right-click, Properties, Local Network Share tab, check Share This Folder and Guest Access

6) On the left-side panel of nautilus click Connect to Server. In Server Address field enter ip -address of your machine smb://192.168.X.XX, connect. You should be able to see test folder appear in the nautilus window titled Windows Shares on 192.168.X.XX

Hope this helps ! Best of luck !

Sources:

File Sharing Not Working on Lan

Sharing Folders Between Two Ubuntu Machines

Nautilus Wants Windows Share Password


How do I configure gitolite3 to use the git account on Ubuntu LTS 16?

Disclaimer: I'm a newbie to both Ubuntu and gitolite.
I think your best option is to go back in time and enter a blank admin key when you first run apt-get install gitolite3.  This will skip the configuration.  Then you can later configure it by running:
dpkg-reconfigure gitolite3

This asks for three configuration parameters: system username, repository path and admin's SSH key.  You can provide git as the user name.
If travelling back in time is not an option, I have found that it's possible to use dpkg-reconfigure gitolite3 on an already installed gitolite system to change the username, but only if you are willing to rm/mv/chmod/chown many directories.  This is more than I would feel comfortable doing on a production system and too risky to provide instructions that people might copy & paste without considering how dangerous they are.
Instead, for an already installed gitolite system, you might consider simply renaming the gitolite3 user.
usermod gitolite3 --login git
groupmod gitolite3 -n git

This will enable the conventional usage of git clone git@server:myrepo.
This will also make things a little inconsistent.  For example
debconf-show gitolite3

will show that the gitolite3 package still thinks the user is gitolite3, but in my limited testing, gitolite still works.


Run script defined in PATH location in the current shell

Based on new information in the OP this answer has been changed.

In your script you need to push the directory you want to end up in when the script finishes:

rick@dell:/$ cat /usr/local/bin/windows
pushd /boot/grub > /dev/null
ls

When you call the script you must but a dot and space in front of it . like this:

────────────────────────────────────────────────────────────────
rick@dell:/$ . windows
fonts             grub.cfg   grubenv  locale       zapgrub.cfg
gfxblacklist.txt  grub.cfg~  i386-pc  unicode.pf2
────────────────────────────────────────────────────────────────
rick@dell:/boot/grub$

Above is simple example of how calling . windows containing the push command works instead of calling windows containing cd command.

For your script you need to change cd "$mount_point"/Users/Justin to pushd "$mount_point"/Users/Justin and call the script with . windows instead of windows


I finally found a post with the answer.

sudo chown root:shadow /etc/gshadow
sudo chown root:shadow /etc/gshadow-
sudo chown root:shadow /etc/shadow
sudo chown root:shadow /etc/shadow-

This is outlined at the post ... Lock screen does not unlock with correct password Gnome and Ubuntu 14.04


How do I configure my DNS settings in Ubuntu server?

Set DNS Servers

You need to configure the /etc/network/interfaces file if you want to change your DNS server via the command line.

It should look something like this:

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.X.X
netmask 255.255.255.0
gateway 192.168.X.X
dns-nameservers X.X.X.X

If you have more than one DNS server, just add a space between each:

dns-nameservers X.X.X.X Y.Y.Y.Y Z.Z.Z.Z

Just replace the Xs, Ys, and Zs with your own IPs of the DNS servers of choice, and when this is done, run this command to update the settings:

sudo ifdown eth0 && sudo ifup eth0

Hope this helps!


Why does Unity depend on Gnome and to what point is the dependency required?

Unity is not an entire graphical desktop.  It is only one small part of it - the desktop shell.  It is one of the most visible parts of an operating system, particularly when you are interacting with the controls it provides or launching applications.

In order to use a graphical desktop you need to have a solid suite of software which comprises everything from a window manager and display manager, to widget toolkits, to file managers, and countless GUI applets for configuring and controlling everything from networking to which application should open which types of files.  You also need a suite of actual applications such as browsers, picture viewers, video players, and more.

Unity could have been written as a shell for any existing desktop suite.  Gnome was chosen because it is relatively full-featured and had already been the default desktop environment for Ubuntu for many years prior.  Thus, with the exception of what Unity provides (which has a very visible immediate difference), the vast majority of your graphical desktop works the same way you were used to from previous versions of Ubuntu, if you stayed with the default Gnome.

Unity is actually implemented as an extension to Compiz, which is not part of Gnome at all.  Compiz is a 3D-accelerated window manager that is designed as an alternative to Gnome 2's metacity and Gnome 3's mutter, though it can be made to work with KDE as well (even though KDE now includes Compiz-like functionality in its own window manager).  Ubuntu have chosen to work Unity and Compiz into the Gnome desktop environment, rather than KDE, for the reasons stated above.  Some development effort would be required to make it work in KDE, even though Compiz itself can be made to work with KDE.  The version of Compiz that is installed by Ubuntu makes use of a number of other Gnome-specific extensions in additional to Unity.

Why is a specific version of Gnome used for a specific Version of Ubuntu

This is just how most Linux distributions work - for a given release of the operating system, all their core software tends to stay at the same version throughout the life of that release, but a new release of the operating  system will typically get newer versions of software.

The version of Gnome that ends up in each Ubuntu release will usually just be the latest version of Gnome that is "ready" (no major problems) at the time that Ubuntu is getting ready for release, given enough time for testing beforehand.

What changes is Unity doing in regards of being less dependent of Gnome

There's no reason to make Unity less dependent on Gnome, so I don't think there's anybody seriously working on that.  If Ubuntu needed to drop Gnome for any reason (which I don't see happening) they'd probably also switch away from Unity, too.

Has the dependency on Gnome created limitations with Unity?

I'm sure that it has influenced Unity's technical decisions along the way, but it will also have granted Unity great freedoms as well, because it is a mature and full-featured desktop environment.  Ubuntu are in no position, and would have no desire, to replace Gnome by building a new desktop environment from scratch.


ifconfig command only displays 'lo" interface but not others on Ubuntu 12.10

You may want to download your wireless driver and install it.
Perhaps you was lacking a driver or the wireless driver may be disabled.


Have you tried running tweaks? It fixed the problem for me on 18.04. Tweaks is a program that allows for customization of various functions like the adjustments you make in your settings. Looks like settings but it has additional options. Available in the Ubuntu store. Tweaks


Ubuntu 16.04. Internet keep disconnecting. Local network is fine

This might be because your DNS servers are not properly configured to avoid future problems you can change the following line in /etc/network/interfaces right at the end so that it looks like this:

dns-nameservers 8.8.8.8 8.8.4.4

This will allow you to use Google's Public DNS. You can change the DNS servers to the ones provided by your ISP.
When you are done save the file and run the command

sudo resolvconf -u

Or simply restart your computer


Did I just delete everything with find -exec mv?

First: stop using this drive now. It's ok to remount it read-only, just make sure not to do any more writing. Yes, you've deleted the pictures. They may be recoverable, but the more you keep using that drive, the less chance you have to recover anything.

Your command ran mv pic1.jpg pictures, mv pic2.jpg pictures, etc. Each invocation of mv overwrote the file currently named pictures by another picture.

Moving a file (within the same filesystem) means detaching it from the directory that contains it and attaching it to the target directory under the new name. So no file data was modified or deleted by this command, only the directory entries for the images that have disappeared.

You can run a tool that scours your filesystem's free space and looks for things that look like jpegs. Fortunately, every jpeg file starts with a recognizable header. Tools that look for deleted content are called carving tools. There are a few in Ubuntu, including recoverjpeg, foremost, testdisk, … If the photos are on a separate home partition or on an external drive, install one or more of those packages and point them to the partition with the deleted pictures.

If the photos are on your system disk, you need to stop using your system immediately. Use another computer to download a live CD or USB and boot from that. Any of the live CDs that include testdisk should fit the bill, but some are easier to use than others. System Rescue CD is a good general-purpose system rescue CD. Ubuntu Rescue Remix may be more familiar for an Ubuntu user.

For future reference, get into the habit of using mv -i unless you aim to overwrite files. You may already have an alias for mv, but that only kicks in when you type mv directly on the command line, not when mv is invoked by a script or by the find command.

$ : >pictures
$ mv -i foo.jpg pictures
mv: overwrite `pictures'?

Also, if you put a / after a name that is supposed to be the name of a directory, you'll get an error if the directory doesn't exist, or if there is a file by that name which isn't a directory.

$ : >pictures
$ mv foo.jpg pictures/
mv: cannot move `foo.jpg' to `pictures/': Not a directory
$ rm pictures
$ mv foo.jpg pictures/
mv: cannot move `foo.jpg' to `pictures/': Not a directory

To avoid the pitfalls of find, you could use bash's recursive directory traversal feature instead. You need to turn it on first with the command shopt -s globstar (you can add this line to your ~/.bashrc. Then:

mv **/*.jpg pictures/

(Note that in bash, **/ also traverses symbolic links to directories, and there's no way to turn this off. If you want a recursive traversal that doesn't look through symbolic links to directories, use zsh or find.)


I think you are looking for creating a chain, not a table.

   -N, --new-chain chain
          Create a new user-defined chain by the given name.  There must be no target of that name already.

Example (-t filter is implied):

iptables -N Services
iptables -A INPUT -j Services
iptables -A Services -m tcp -p tcp --dport 80 -j ACCEPT

Tables can be selected with the -t option:

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

And if you are using iptables-restore, the above two rules can be combined to:

*nat
-A POSTROUTING -j MASQUERADE
COMMIT

*filter
:Services -
-A INPUT -j Services
-A Services -m tcp -p tcp --dport 80 -j ACCEPT
COMMIT


How to get remote access from Windows to Ubuntu's laptop without additional networking devices?

There are several programs to do this GUI side, but I recommend Synergy.

https://symless.com/synergy/

https://www.digitalocean.com/community/tutorials/how-to-set-up-ssh-keys--2

Another alternative for seeing the other screen is teamviewer.  Its not what most developers would use, but suitable to use another computer remotely or through network.