Proceed to Safety



Really tiny print output

Undesirable Scroll Wheel Behaviour

Lubuntu/LXDM: Disable Tap-to-Click

Sudden Cursor Jumps When Clicking

Debugging a Slow Shutdown

GRUB 2 Configuration

Concise Package Install Log

Undesirable Scroll Wheel Behaviour

These are actually the same problem, oddly enough.

On the LibreOffice Forum can be found a query about printing:

Printouts extremely tiny
(Date: 2010 Dec 01)
So far the only way I can get a usable printout from LibreOffice is to export to .pdf, then print from document viewer. If I print the document directly (from preview, from the file menu, in Writer, Draw, or Calc) a full page will be shrunk down to about two inches high.

LibreOffice Beta 2 and 3, Ubuntu 10.10

HP Deskjet F4480

The responses were no more enlightened than the typical "did you try rebooting?" type of advice:

I encountered this problem too and found that indeed my printer's Job Options "Pages per side" had been changed. But how? Soon I figured out the problem, and wrote:

It happened to me too, and I know why. :-D

I went into the printer job options that you described (In Ubuntu 14 Unity, it’s System Settings > Printers > (double-click your printer, Properties window appears) > Job Options)

Then I tried to scroll down using the mouse wheel.

Guess what? If the cursor is over any option and you move the mouse wheel, it changes the option! Yes, that’s right, the scroll wheel isn’t just for scrolling anymore, it also changes anything you’re pointing at. I must have done this a few times, because my default magnification and page orientation had been mysteriously changing too.

Does anyone know how to kill this useless scroll wheel behaviour?

Lubuntu/LXDE: Disable Tap-to-Click

Lubuntu ("lightweight" Ubuntu) uses the LXDE window manager / desktop environment, and is somewhat light on customisation settings. Notably missing are any ways to change trackpad / touchpad behaviour, like this one.

"Tap to Click" is a default in most versions of all modern operating systems, and started in the early days of touchpads when it was noticed that a lot of people just can't handle the physical requirements of the mechanical "clicker" in a trackpad, particularly if they're trying to double-click or click-and-drag.

Lubuntu uses several touchpad drivers, depending on your hardware. To find out which one, use this:

egrep -i 'synapalpsetps' /proc/bus/input/devices

The following only applies if you have Synaptics-type hardware. For example, when I type the above I see that I have a "SynPS/2 Synaptics TouchPad". It works in Ubuntu-type Linuces from 13.10 through 16.04 (and probably later).

To disable "Tap-to-Click" in the LXDE graphical environment:

Alternative method for LXDE:

Command-Line Method

Disabling "Tap-to-Click" from the command line works in any window environment, including really small ones like IceWM and full-blown ones like Unity.

Making the Change Persist

To make the change permanent, the "synclient MaxTapTime=0" command has to be executed sometime during X Windows startup. Where you put it will depend on what type of window manager you're using. Several options are available; see this AskUbuntu question for examples.

The following method works for folks who still boot in mode 3 (TTY login prompt) and start X windows manually. It shuld work with almost all window managers and desktop environments that are capable of starting themselves in single-user mode when launched from a shell that was logged in at the TTY. Edit your ~/.xinitrc, and make it begin as follows:

# ~/.xinitrc synclient MaxTapTime=0 synclient AreaBottomEdge=3400    # now run whatever window manager is installed /etc/X11/xinit/xinitrc    # ... # (rest of .xinitrc follows) # ...

For LXDE the solution is described above. Other window managers will have their own quirky or specific ways of including customisations and settings that formerly would have all been called from .xinitrc. The resource-heavy window managers (like Ubuntu's standard Unity, and Gnome and KDE) all have their own trackpad settings "control panels" that include an option to turn off Tap to Click.

Making the Change Globally

If your system has multiple accounts, and if you really want them all to get this change, then you can (as root) add a file to /usr/share/X11/xorg.conf.d/ with a name like "77-syn-notapclick.conf".

Section "InputClass" Identifier "touchpad" Driver "synaptics" MatchIsTouchpad "on" Option "MaxTapTime" "0" EndSection

This initialsation is caught by the X Windows that is started up by the system before logging in a user, but it should also work for a X Windows session started from a TTY shell.

Sudden Cursor Jumps When Clicking

If you need to turn off "Tap to Click" (previous item), it's probably because you have a "clickpad", a touchpad with a mechanical "mouse-click" mechanism below it so that you press down on the touchpad to do a click. Depending on the details of the hardware, and how you move your hand/fingers, you might notice that sometimes the cursor jumps way down when you try to click on something. This can cause the click to go in the wrong place, or cause a sudden "drag".

This problem happens because when you use a second finger (most commonly the thumb) to do the "click", the touchpad interprets that as a rapid movement of the first finger (the one you used to position the cursor before clicking).

The problem is fixed by telling it to treat the bottom part of the touchpad as a "dead zone", ignoring touches in that area. (It won't become completely dead — the bottom area needs to be ignored if a touch begins in the bottom, but it can still be active for touch-drag operations that start in the middle of the touchpad and move down.)

The relevant synclient variable is called "AreaBottomEdge". It is normally a rather large number (on my system is was 4467). The number needs to be decreased, to effective move the "bottom edge" up from the real bottom. To find a good value, examine the existing settings with the command

synclient -l | grep Area.*Edge

Look for AreaTopEdge and AreaBottomEdge and note their present values. The new value of AreaBottomEdge should be between these two, and the value will determine how much of the touchpad becomes "dead". For example if you use a new value that is halfway between the original AreaTopEdge and AreaBottomEdge values, then the bottom half of the touchpad will be "dead".

On my system the original values were AreaTopEdge=1445 and AreaBottomEdge=4467. I wanted to use the bottom 1/3 of the touchpad for my thumb to click, so I chose 3400 as a value about 2/3 of the way from 1445 to 4467. I ended up using a similar method as above adding this command to the LXDE startup:

synclient AreaBottomEdge=3400


Ask Ubuntu pages:

   How do I disable touchpad tap to click?

   How do I make my synclient settings stick?

   How to disable tap to click in Lubuntu 13.10

   Tap to click - short mouse movements registering as a click

Arch Linux wiki, Touchpad Synaptics

Debugging a Slow Shutdown

(%%% notes in linux.rare.txt)

GRUB 2 Configuration

GRUB is a GNU software project used as one stage of the multi-stage boot process for many distributions of Linux, notably Ubuntu. (The acronym is not recursive — it stands for "GRand Unified Bootloader")

In the original GRUB one could create multiple menus by editing a file called "grob.cfg" which looked like this:

# various insmod and settings might be here    menuentry "Try Lubuntu without installing" { set gfxpayload=keep linux /casper/vmlinuz.efi persistent file=/cdrom/preseed/lubuntu.seed boot=casper loglevel=3 --- initrd /casper/initrd.lz }    menuentry " Lvl-3 boot messages and TTY login" { set gfxpayload=keep linux /casper/vmlinuz.efi persistent file=/cdrom/preseed/lubuntu.seed boot=casper earlyprintk=vga,keep pcie_aspm=off loglevel=3 3 --- initrd /casper/initrd.lz }

A user wishing to add additional menu choices for things like boot to TTY or log levels could just copy one of the "menuentry" blocks and make the appropriate changes.

Unfortunately, that makes it tough for software updates to add new kernels and automatically update the menus to give users a choice of which kernel to boot (in case the new one doesn't work). Eventually it was decided to put grub.cfg "off-limits", or at least to deprecate the act of editing it.

How to Add Menu Items in GRUB 2

You can still have custom menus. Edit /etc/grub.d/40_custom

#!/bin/sh exec tail -n +3 $0 # This file provides an easy way to add custom menu entries. Simply add # menu entries after this comment. Be careful not to change the 'exec tail' # line above.    menuentry "Boot from USB Drive" { # Discover the USB drive's ext4 partition UUID the "blkid" command # Then put that UUID in place of "XXXX-YYYY" in both places below set root=UUID=XXXX-YYYY linux /vmlinuz root=UUID=XXXX-YYYY ro quiet splash initrd /initrd.img }


Concise Package Install Log

( zcat $( ls -tr /var/log/apt/history.log*.gz ) ; \ cat /var/log/apt/history.log ) \ | egrep '(Start-Date|Commandline)' \ | grep -v aptdaemon | grep -v APT..Keep-Fds \ | grep -B1 '^Commandline'


Ask Ubuntu:

   How to list all installed packages

   How to backup settings and list of installed packages

   How to migrate the whole system to a new machine?

(If you want to see how I felt about this way back in the late 1990's here is a link to the old rules and rants page from 2000. In the meantime I've realised Microsoft actually spents a lot more effort on long-term backwards compatibility than, say, Apple; but Linux is still better because for the most part you can choose what software and which versions of each to run, and keep it that way; and when necessary use the source code to perform debugging and fix problems.)

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This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2016 Aug 13. s.27