Replacing the KDE Plasma widget ‘Thermal Monitor’ with ‘Kargos’ in Gentoo Linux

The KDE Plasma widget Thermal Monitor has not been working correctly in my Gentoo Linux installations for quite some time. I notice Thermal Monitor’s repository has not been updated for a couple of years, despite several new versions of KDE Plasma having been released. Perhaps that is the reason.

On my laptop running the Stable Branch of Gentoo Linux, Thermal Monitor displays the GPU and HDD temperatures automatically but CPU temperatures were only displayed if I right-clicked on the widget and selected ‘Reload Temperature Sources’. I managed to get the widget to display the CPU temperatures automatically by editing the file ~/.local/share/plasma/plasmoids/org.kde.thermalMonitor/contents/ui/main.qml and commenting out a line as shown in the file excerpt below:

[...]
        onSourceAdded: {

            if (source.indexOf(lmSensorsStart) === 0 || source.indexOf(acpiStart) === 0) {
/*
 *                systemmonitorAvailableSources.push(source)
 */
                var staIndex = systemmonitorSourcesToAdd.indexOf(source)
                if (staIndex > -1) {
                    addToSourcesOfDatasource(systemmonitorDS, source)
                    systemmonitorSourcesToAdd.splice(staIndex, 1)
                }

            }

        }
[...]

The above modification is suggested in a comment to Issue #53 in the widget’s repository.

However, the above-mentioned edit does not fix Thermal Monitor on my laptop running the Testing Branch of Gentoo Linux, and Thermal Monitor no longer displays the GPU temperature either. Actually, the CPU’s four core temperatures and the GPU temperature are no longer listed in the Thermal Monitor configuration window, only a single CPU temperature. Not surprisingly, none of the suggested changes to the file ~/.local/share/plasma/plasmoids/org.kde.thermalMonitor/contents/ui/main.qml that I found in Web searches made a difference. However, while researching the problem I came across a Manjaro Forums post by user bogdancovaciu about the Kargos Plasma widget, a KDE Plasma port of GNOME Argos and OSX BitBar. Kargos enables you to create a Plasma widget that runs your own script, which can be written in any language, providing its output adheres to a specified format. I also found a repository named k-argos-plugins containing further example scripts for Kargos. As none of the solutions suggested for Thermal Monitor in that Manjaro thread worked for me, I decided to try the Kargos widget instead. It works a treat.

kargos widget on KDE Plasma Panel

kargos widget on KDE Plasma Panel of my Compal NBLB2 laptop

Below I explain what I did to install and configure the Kargos widget on my KDE Panel in Gentoo Linux (see screenshot). The packages lm-sensors and hddtemp were already installed in my case, but if they had not been, I would have needed to install and configure them, so I have included those steps below.

1. Install and configure lm-sensors

root # emerge lm-sensors
root # rc-update add lm_sensors default
root # sensors-detect

In my case sensors-detect created the file /etc/modules-load.d/lm_sensors.conf containing only the following:

# Generated by sensors-detect on Sun Oct 27 03:07:08 2019
coretemp

2. Start lm-sensors now, rather than rebooting

root # /etc/init.d/lm_sensors start

3. I wanted to use the nc command in my shell script for Kargos, so I installed its package

root # emerge netcat

4. Install and configure hddtemp

root # emerge hddtemp
root # rc-update add hddtemp default

Specify in the config file /etc/conf.d/hddtemp which drives to check:

# Copyright 1999-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# the hddtemp executable
HDDTEMP_EXEC=/usr/sbin/hddtemp

# various options to pass to the daemon
HDDTEMP_OPTS="--listen=127.0.0.1"

# a list of drives to check
HDDTEMP_DRIVES="/dev/sda"

5. Start hddtemp now, rather than rebooting

root # /etc/init.d/hddtemp start

6. Install Kargos

On the KDE Plasma Desktop, click on the ‘Desktop’ menu icon (the three horizontal lines in the top right corner of the Desktop) and select: ‘Unlock Widgets’ > ‘Add Widgets…’ > ‘Get New Widgets…’ > ‘Download New Plasma Widgets’. Search for, and install, ‘kargos’ widget.

7. Create the Bash script ~/temperatures.3s.sh containing the following:

#!/bin/bash
temp=$(sensors | grep -oP 'Core.*?\+\K[0-9.]+')
temp0=$(sensors | grep 'Core 0' | cut -c '16-17')
temp1=$(sensors | grep 'Core 1' | cut -c '16-17')
temp2=$(sensors | grep 'Core 2' | cut -c '16-17')
temp3=$(sensors | grep 'Core 3' | cut -c '16-17')
hdd_temp=$(nc localhost 7634 | cut -c '33-34')
gpu_temp=$(sensors | grep -A 2 'radeon' | grep 'temp1' | cut -c '16-17')
echo "<br><font size='1'>CPU1&nbsp;&nbsp;CPU2&nbsp;&nbsp;CPU3&nbsp;&nbsp;CPU4&nbsp;&nbsp;GPU&nbsp;&nbsp;HDD</font><br>${temp0%%.*}°&nbsp;&nbsp;${temp1%%.*}°&nbsp;&nbsp;${temp2%%.*}°&nbsp;&nbsp;${temp3%%.*}°&nbsp;${gpu_temp}°&nbsp;${hdd_temp}°| font=Hack-Regular size=10"
# Uncomment the lines below if you want to be able to click on the kargos widget and display a pop-up TOP
#echo "---"
#TOP_OUTPUT=$(top -b -n 1 | head -n 20 | awk 1 ORS="\\\\n")
#echo "$TOP_OUTPUT | font=monospace iconName=htop"

The script above is specifically for the temperature sensors in my Clevo NBLB2 laptop. To find out which temperatures are available, and which characters to extract, use the following command:

root # sensors

Don’t forget to make the script executable:

user $ chmod +x ~/temperatures.3s.sh

Note that the ‘.3s‘ in the script name is optional but, if included, will override the kargos configuration (see further on) and run the script every 3 seconds. I could have specified another frequency, such as ‘.5s‘ or whatever.

8. Add the kargos widget to the KDE Panel.

9. Right-click on the kargos widget on the KDE Panel and select ‘Configure kargos…’.

10. Configure the kargos widget

In the first box in the configuration window, enter the full path of the script:

/home/fitzcarraldo/temperatures.3s.sh

In the second box leave ‘Interval in seconds’ as ‘1‘. This is overridden anyway if the script filename includes the interval.

In the third box leave ‘Rotation delay in seconds’ as ‘6‘.

On the KDE Plasma Desktop, click on the Desktop menu icon (three horizontal lines) and select: ‘Lock Widgets’.

11. Depending on the font configuration for the KDE Desktop, it may be necessary to edit the Bash script ~/temperatures.3s.sh to change the font name or size, the number of non-breaking spaces between the names displayed on the top line, and the number of non-breaking spaces between the temperature values displayed on the bottom line.

How to enable a Windows application in WINE to access a Samba share on a NAS (continued)

In a 2016 post ‘How to enable a Windows application in WINE to access a Samba share on a NAS‘ I explained how to mount in Linux a networked SMB shared folder so that a Windows application running via WINE could access the folder as Drive Y: in order to open and save files in it. In that blog post I also listed a couple of Bash scripts to facilitate the mounting and unmounting of the SMB share for the WINEPREFIX used for the Windows application (~/.wine-pdfxve6 in the example I gave for PDF-XChange Editor, Version 6). However, as I have several Windows applications running via WINE on my machines, and I have used a different WINEPREFIX for each of them, I wanted to be able to mount the SMB share for whichever of those applications I happen to be using at the time. Therefore I modified the original Bash scripts as shown below. The Desktop Configuration files (.desktop files) to launch the scripts are essentially the same as in my earlier blog post; I have just removed the references to the specific Windows application. The four modified files are listed below. Obviously change the username, SMB share name and SMB server name to suit your own situation.

1. Bash script ~/mount_bsfnas1_brianfolder_share.sh

#!/bin/bash
mount_share () {
    echo
    echo "Enter your Linux account password below..."
    echo
    sudo ln -s /media/bsfnas1/brianfolder ~/$PREFIX/dosdevices/y:
    sudo mount.cifs //bsfnas1/brianfolder/ -o user=brianfolder,pass=enricocaruso,uid=$(id -u),gid=$(id -g) ~/$PREFIX/dosdevices/y:
}
echo
echo "This will mount the Samba share folder brianfolder on the bsfnas1 machine."
echo
echo
echo "== Select which WINEPREFIX you wish to use =="
echo
ls ~/.wine-* | grep .wine | awk -F'/' '{print NR " " substr($4, 1, length($4)-1)}'
NUMPREFIXES=$(ls ~/.wine-* | grep .wine | wc -l)
echo
read -p "Enter number (q to abort) and press ENTER: " CHOICE
if [ "$CHOICE" != "q" ] && [ "$CHOICE" -gt 0 ] && [ "$CHOICE" -le $NUMPREFIXES ]; then
    PREFIX=$(ls ~/.wine-* | grep .wine | awk -F'/' '{print NR " " substr($4, 1, length($4)-1)}' | grep "$CHOICE " | awk -F' ' '{print $2}')
    echo
    if [ ! -e ~/$PREFIX/dosdevices/y: ]; then
        mount_share
    else
        echo -n "~/$PREFIX/dosdevices/y: already exists. Is it OK to proceed anyway (y/n)? "
        read ANSWER
        if [ $ANSWER = "y" ]; then
            rm ~/$PREFIX/dosdevices/y:
            mount_share
        fi
    fi
    echo
fi
if grep -q "/media/bsfnas1/brianfolder" /proc/mounts; then
    echo "Samba share //bsfnas1/brianfolder is mounted for WINEPREFIX ~/$PREFIX ."
else
    echo "Samba share //bsfnas1/brianfolder is not mounted."
fi
echo
echo "You may now close this window."
read ANSWER
exit

2. Bash script ~/umount_bsfnas1_brianfolder_share.sh

#!/bin/bash
echo
echo "This will unmount the Samba share folder brianfolder on the bsfnas1 machine."
echo
echo "Enter your Linux account password below..."
echo
sudo umount ~/.wine-*/dosdevices/y: 2>/dev/null
echo
if grep -q "/media/bsfnas1/brianfolder" /proc/mounts; then
  echo "Samba share //bsfnas1/brianfolder is mounted."
else
  echo "Samba share //bsfnas1/brianfolder is not mounted."
fi
echo
echo "You may now close this window."
exit

3. Desktop Configuration file ~/Desktop/mount_bsfnas1_brianfolder_share.desktop

[Desktop Entry]
Comment[en_GB]=Mount bsfnas1 brianfolder share for current WINEPREFIX
Comment=Mount bsfnas1 brianfolder share for current WINEPREFIX
Exec=sh /home/fitzcarraldo/mount_bsfnas1_brianfolder_share.sh
GenericName[en_GB]=Mount bsfnas1 brianfolder share for current WINEPREFIX
GenericName=Mount bsfnas1 brianfolder share for current WINEPREFIX
Icon=media-mount
MimeType=
Name[en_GB]=mount_bsfnas1_brianfolder_share
Name=mount_bsfnas1_brianfolder_share
Path=
StartupNotify=true
Terminal=true
TerminalOptions=\s--noclose
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

4. Desktop Configuration file ~/Desktop/umount_bsfnas1_brianfolder_share.desktop

[Desktop Entry]
Comment[en_GB]=Unmount bsfnas1 brianfolder share for current WINEPREFIX
Comment=Unmount bsfnas1 brianfolder share for current WINEPREFIX
Exec=sh /home/fitzcarraldo/umount_bsfnas1_brianfolder_share.sh
GenericName[en_GB]=Unmount bsfnas1 brianfolder share for current WINEPREFIX
GenericName=Unmount bsfnas1 brianfolder share for current WINEPREFIX
Icon=media-eject
MimeType=
Name[en_GB]=umount_bsfnas1_brianfolder_share
Name=umount_bsfnas1_brianfolder_share
Path=
StartupNotify=true
Terminal=true
TerminalOptions=\s--noclose
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

Now when I double-click on the icon to mount the SMB share for a Windows application running via WINE, a terminal window pops up displaying the WINEPREFIXs currently installed on my machine:


This will mount the Samba share folder brianfolder on the bsfnas1 machine.


== Select which WINEPREFIX you wish to use ==

1 .wine-3dimviewer
2 .wine-myphoneexplorer
3 .wine-nbtscan
4 .wine-pdfxve6
5 .wine-PortableApps
6 .wine-radiant
7 .wine-symmetry
8 .wine-visio
9 .wine-xnviewmp

Enter number (q to abort) and press ENTER: 

Let’s say I want to use the Windows application XnViewMP. I would enter ‘9’ and press ‘Enter’. The rest of the interaction should be obvious:


This will mount the Samba share folder brianfolder on the bsfnas1 machine.


== Select which WINEPREFIX you wish to use ==

1 .wine-3dimviewer
2 .wine-myphoneexplorer
3 .wine-nbtscan
4 .wine-pdfxve6
5 .wine-PortableApps
6 .wine-radiant
7 .wine-symmetry
8 .wine-visio
9 .wine-xnviewmp

Enter number (q to abort) and press ENTER: 9

~/.wine-xnviewmp/dosdevices/y: already exists. Is it OK to proceed anyway (y/n)? y

Enter your Linux account password below...

[sudo] password for fitzcarraldo: 

Samba share //bsfnas1/brianfolder is mounted for WINEPREFIX ~/.wine-xnviewmp .

You may now close this window.

Henceforth the Windows application XnViewMP will be able to access the Y: drive which is actually the SMB share //bsfnas1/brianfolder.

Once I have finished using the application, I just double-click on the the icon to unmount the SMB share, and a terminal window pops up displaying the following:


This will unmount the Samba share folder brianfolder on the bsfnas1 machine.

Enter your Linux account password below...

[sudo] password for fitzcarraldo: 

Samba share //bsfnas1/brianfolder is not mounted.

You may now close this window.

Once I have entered my Linux password for the local machine, the script will unmount the SMB share and the terminal window will close automatically if you have configured the Desktop Configuration file by right-clicking on the icon and unticking ‘Do not close when command exits’ in KDE, ‘Keep terminal window open after command execution’ in LXDE, or similar in other desktop environments.

Note: If you use Microsoft Office via WINE, you also might be interested in a comment on my earlier blog post about a Microsoft Office problem in saving files to a remote SMB share.

Creating a RAID of USB pendrives in Linux

USB hub and USB pendrives used as RAID10 with my laptop

USB hub and pendrives used as RAID10 with my laptop.

If you’re not familiar with the RAID (Redundant Array of Inexpensive Disks) concept and the different types of array, the article ‘RAID 0, RAID 1, RAID 5, RAID 10 Explained with Diagrams‘ gives a quick summary (and links to another article ‘RAID 2, RAID 3, RAID 4, RAID 6 Explained with Diagram‘). Another helpful article is ‘RAID Levels Explained‘.

A few years ago I came across a YouTube video by a Mac user, titled ‘Use a bunch of USB Flash drives in a RAID array‘. Purely out of interest he had experimented with creating RAIDs using USB pendrives (also known as ‘USB flash drives’ or ‘USB memory sticks’). The creation of a RAID using USB pendrives for his Apple Macs was very easy, and, since then, I had wanted to try this using one of my laptops running Linux, just to satisfy my curiosity. I have previously created software RAIDs in a Linux server using internal 3.5-inch HDDs, for the root, home and swap partitions, and for file storage partitions for a Cloud server and NAS. However, I had never created a RAID using external USB drives. This week I happened to have a spare four-port USB 3.0 hub and four old 4GB USB 2.0 pendrives, so I finally got the chance to create a RAID with USB pendrives (see photo). I decided to use my main laptop, which has Gentoo Linux with OpenRC, elogind, eudev and KDE installed. That installation does not have an initramfs so I did not need to rebuild an initramfs to assemble the RAID. Anyway, early assembly of a RAID by an initramfs would only be needed if the RAID were being used to hold the directories required by the OS (the root partition, for example). As my RAID would be pluggable external storage, I wanted to mount it manually rather than adding it to /etc/fstab to be mounted automatically at boot. As I had not used a RAID on this laptop before, I had not enabled the RAID drivers in the kernel configuration, so I needed to do that and rebuild the kernel. I opted to make the RAID drivers kernel modules rather than built into the kernel, so that I could load only the relevant module for whichever type of RAID I wished to create.

I had to decide which filesystem to use in the RAID. I have always used ext4 in my RAIDs using HDDs. However, F2FS is an interesting filesystem developed by Samsung for devices using flash memory, such as SD cards, USB pendrives and SSDs. So I decided to format the pendrives to use F2FS, and create an F2FS RAID. As I had not used F2FS previously on this laptop, I had not enabled the F2FS driver in the kernel configuration, so I enabled the F2FS driver in the kernel at the same time as I enabled the RAID drivers. As with the RAID drivers, I opted to make the F2FS driver a kernel module rather than built into the kernel, so that I could load it and unload it whenever I wanted.

Not only did it turn out to be easy to create a RAID using USB pendrives, I found that the Linux RAID module gets loaded automatically when I connect the USB hub. Furthermore the RAID is recognised by KDE and listed under ‘Places’ in the Dolphin file manager’s windows, which I can click on to mount and unmount the RAID. So I did not even need to configure the OS to load the RAID module at boot (the OS does not load the module automatically at boot if the hub is not connected).

DigitalOcean produced a good tutorial on creating RAIDs in Ubuntu: ‘How To Create RAID Arrays with mdadm on Ubuntu 16.04‘. The procedure is essentially the same in Gentoo Linux, the only differences being the path of the mdadm.conf file and the method of updating an initramfs (which I did not need to do anyway in this particular installation).

As I had four spare USB pendrives and a four-port hub, I decided to create a RAID10 array. Below is a summary of the steps I took.

1. I rebuilt the kernel in order to build the RAID and F2FS modules. The relevant kernel configuration parameters I set are shown below:

root # grep RAID /usr/src/linux/.config | grep -v "#"
CONFIG_MD_RAID0=m
CONFIG_MD_RAID1=m
CONFIG_MD_RAID10=m
CONFIG_MD_RAID456=m
CONFIG_ASYNC_RAID6_RECOV=m
CONFIG_RAID6_PQ=m
root # grep F2FS /usr/src/linux/.config | grep -v "#"
CONFIG_F2FS_FS=m
CONFIG_F2FS_STAT_FS=y
CONFIG_F2FS_FS_XATTR=y
CONFIG_F2FS_FS_POSIX_ACL=y
root # uname -a
Linux clevow230ss 4.19.72-gentoo #2 SMP Tue Oct 15 01:36:57 BST 2019 x86_64 Intel(R) Core(TM) i7-4810MQ CPU @ 2.80GHz GenuineIntel GNU/Linux

2. I installed the mdadm tool:

root # eix -I mdadm
[I] sys-fs/mdadm
     Available versions:  4.1^t {static}
     Installed versions:  4.1^t(01:52:17 15/10/19)(-static)
     Homepage:            https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/
     Description:         Tool for running RAID systems - replacement for the raidtools

3. I installed the F2FS tools:

root # eix -I f2fs
[I] sys-fs/f2fs-tools
     Available versions:  1.10.0(0/4) 1.11.0-r1(0/5) 1.12.0-r1(0/6) ~1.13.0(0/6) {selinux}
     Installed versions:  1.12.0-r1(0/6)(02:05:17 15/10/19)(-selinux)
     Homepage:            https://git.kernel.org/cgit/linux/kernel/git/jaegeuk/f2fs-tools.git/about/
     Description:         Tools for Flash-Friendly File System (F2FS)

4. I rebooted the laptop.

5. The f2fs module was not loaded automatically, therefore I loaded it manually and edited /etc/conf.d/modules to add the module name so that it would be loaded automatically in future:

root # modprobe f2fs
root # lsmod | grep f2fs
f2fs                  466944  0
root # nano /etc/conf.d/modules
root # grep ^modules /etc/conf.d/modules
modules="fuse bnep rfcomm hidp uvcvideo cifs mmc_block snd-seq-midi iptable_raw xt_CT uinput f2fs"

6. I plugged the four USB pendrives into the USB hub, and connected the hub to the laptop.

7. I launched GParted, deleted the existing partition on each pendrive (three had been formatted as FAT32, one as exFAT), reformatted them individually as F2FS and gave them each a label (USBPD01 to USBPD04). I could have done all that from the command line but it is easier using GParted, and I like an easy life.

Note that the mdadm USE flag in Gentoo Linux needed to be set when GParted was merged, so GParted would need to be re-merged with USE="mdadm" if that is not the case. Furthermore, GParted will only include F2FS in the list of available filesystems if either the F2FS module is loaded or the F2FS driver has been built into the kernel.

8. I ascertained the names of the USB pendrives:

root # lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
NAME     SIZE FSTYPE TYPE MOUNTPOINT
sda    698.7G        disk
├─sda1   128M ext2   part
├─sda2    16G swap   part [SWAP]
├─sda5   128G ext4   part /
├─sda6   256G ext4   part /home
└─sda7 298.5G ntfs   part /media/NTFS
sdb      3.8G        disk
└─sdb1   3.8G f2fs   part
sdc      3.8G        disk
└─sdc1   3.8G f2fs   part
sdd      3.8G        disk
└─sdd1   3.8G f2fs   part
sde      3.8G        disk
└─sde1   3.8G f2fs   part

As you can see above, the four USB pendrives are sdb to sde.

9. I loaded the raid10 module:

root # modprobe raid10
root # lsmod | grep raid
raid10                 57344  1

10. I created the RAID10 array:

root # mdadm --create --verbose /dev/md0 --level=10 --raid-devices=4 /dev/sdb /dev/sdc /dev/sdd /dev/sde
mdadm: layout defaults to n2
mdadm: layout defaults to n2
mdadm: chunk size defaults to 512K
mdadm: partition table exists on /dev/sdb
mdadm: partition table exists on /dev/sdb but will be lost or
       meaningless after creating array
mdadm: partition table exists on /dev/sdc
mdadm: partition table exists on /dev/sdc but will be lost or
       meaningless after creating array
mdadm: partition table exists on /dev/sdd
mdadm: partition table exists on /dev/sdd but will be lost or
       meaningless after creating array
mdadm: partition table exists on /dev/sde
mdadm: partition table exists on /dev/sde but will be lost or
       meaningless after creating array
mdadm: size set to 3913728K
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

It takes a while for the RAID to be created, so I checked progress periodically as follows:

root # cat /proc/mdstat
Personalities : [raid10]
md0 : active raid10 sde[3] sdd[2] sdc[1] sdb[0]
      7827456 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
      [>....................]  resync =  2.8% (222272/7827456) finish=23.8min speed=5308K/sec
      
unused devices: <none>
root # cat /proc/mdstat
Personalities : [raid10]
md0 : active raid10 sde[3] sdd[2] sdc[1] sdb[0]
      7827456 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
      [========>............]  resync = 44.0% (3449856/7827456) finish=12.9min speed=5637K/sec
      
unused devices: <none>
root # cat /proc/mdstat
Personalities : [raid10]
md0 : active raid10 sde[3] sdd[2] sdc[1] sdb[0]
      7827456 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
      [==============>......]  resync = 74.0% (5797760/7827456) finish=5.9min speed=5698K/sec
      
unused devices: <none>
root # cat /proc/mdstat
Personalities : [raid10]
md0 : active raid10 sde[3] sdd[2] sdc[1] sdb[0]
      7827456 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
      
unused devices: <none>

11. I formatted the RAID:

root # sudo mkfs.f2fs -f /dev/md0

        F2FS-tools: mkfs.f2fs Ver: 1.12.0 (2018-11-12)

Info: Disable heap-based policy
Info: Debug level = 0
Info: Trim is enabled
Info: Segments per section = 1
Info: Sections per zone = 1
Info: sector size = 512
Info: total sectors = 15654912 (7644 MB)
Info: zone aligned segment0 blkaddr: 512
Info: format version with
  "Linux version 4.19.72-gentoo (root@clevow230ss) (gcc version 8.3.0 (Gentoo 8.3.0-r1 p1.1)) #2 SMP Tue Oct 15 01:36:57 BST 2019"
Info: [/dev/md0] Discarding device
Info: This device doesn't support BLKSECDISCARD
Info: This device doesn't support BLKDISCARD
Info: Overprovision ratio = 2.300%
Info: Overprovision segments = 179 (GC reserved = 94)
Info: format successful

The option ‘-f‘ forces mkfs to overwrite any existing filesystem. (I believe the same option is ‘-F‘ in Ubuntu, rather than ‘-f‘.)

12. I created a mount point so I could mount the RAID from the command line if I wanted:

root # mkdir -p /mnt/md0

13. I mounted the RAID from the command line and checked its size. In the case of RAID10 I would expect the size to be double the size of one of the formatted USB pendrives, i.e. approximtely 2 x 3.8GB = 7.6GB):

root # mount /dev/md0 /mnt/md0
root # df -h -x devtmpfs -x tmpfs
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       126G   36G   84G  31% /
/dev/sda6       252G  137G  103G  57% /home
/dev/sda7       299G  257G   43G  86% /media/NTFS
/dev/md0        7.5G  419M  7.1G   6% /mnt/md0
root # blkid | grep -v sda
/dev/md0: UUID="d565c117-37e0-48eb-b635-a2fe70b83272" TYPE="f2fs"
/dev/sdb: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="45a488a0-5126-0b95-0c28-eb1f743f77c7" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/sdc: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="ef7de228-cf4d-c6bf-c74a-462a0e27f8bd" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/sdd: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="b5dd5c41-3ab2-fa38-bd28-0b965883775c" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/sde: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="16149e7e-5a96-ece6-65ba-25721bcee49f" LABEL="clevow230ss:0" TYPE="linux_raid_member"

So /dev/md0 looked correct.

14. I checked that nothing was already configured in mdadm.conf and added the array’s details to it:

root # grep -v "#" /etc/mdadm.conf
root # mdadm --detail --scan | sudo tee -a /etc/mdadm.conf
ARRAY /dev/md0 metadata=1.2 name=clevow230ss:0 UUID=d1288120:a1614809:3e89bb5f:967df69b
root # grep -v "#" /etc/mdadm.conf
ARRAY /dev/md0 metadata=1.2 name=clevow230ss:0 UUID=d1288120:a1614809:3e89bb5f:967df69b

15. As the RAID will have only a partition for file storage, and as the RAID array will not always be connected to the laptop, it does not need to be assembled automatically early during boot, so there is no need to add mdadm.conf to an initramfs (which this laptop does not have anyway) and no need to specify /dev/md0 in /etc/fstab to be mounted at boot.

16. I left the USB hub connected to the laptop and rebooted.

17. I checked that the modules were loaded at boot:

root # lsmod | grep raid
raid10                 57344  1
root # lsmod | grep f2fs
f2fs                  466944  0

18. I checked that the RAID had been assembled correctly at boot:

root # blkid | grep -v sda
/dev/sdb: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="45a488a0-5126-0b95-0c28-eb1f743f77c7" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/sdc: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="ef7de228-cf4d-c6bf-c74a-462a0e27f8bd" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/sdd: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="b5dd5c41-3ab2-fa38-bd28-0b965883775c" LABEL="clevow230ss:0" TYPE="linux_raid_member"
/dev/md0: UUID="d565c117-37e0-48eb-b635-a2fe70b83272" TYPE="f2fs"
/dev/sde: UUID="d1288120-a161-4809-3e89-bb5f967df69b" UUID_SUB="16149e7e-5a96-ece6-65ba-25721bcee49f" LABEL="clevow230ss:0" TYPE="linux_raid_member"

19. I rebooted a few times with and without the USB hub connected. The module raid10 only gets loaded if the USB hub is connected. If I reboot without the hub connected, raid10 is no longer loaded automatically at boot. If I plug in the hub after the laptop has booted, raid10 gets loaded and the RAID array is recognised by the OS.

20. I mounted the RAID from the command line and copied a file to it as root user:

root # mount /dev/md0 /mnt/md0
root # ls -la /mnt/md0
total 8
drwxr-xr-x 2 root root 4096 Oct 15 07:40 .
drwxr-xr-x 7 root root 4096 Oct 15 07:42 ..
root # cp ./Paper_sheet_sizes.png /mnt/md0
root # ls -la /mnt/md0
total 268
drwxr-xr-x 2 root root   4096 Oct 15 08:07 .
drwxr-xr-x 7 root root   4096 Oct 15 07:42 ..
-rw-r--r-- 1 root root 265760 Oct 15 08:07 Paper_sheet_sizes.png
root # umount /dev/md0
root # ls -la /mnt/md0
total 8
drwxr-xr-x 2 root root 4096 Oct 15 07:42 .
drwxr-xr-x 7 root root 4096 Oct 15 07:42 ..

However, /mnt/md0/ is owned by the root user, so user fitzcarraldo cannot copy files into it. Therefore I changed the ownership:

root # mount /dev/md0 /mnt/md0
root # ls -la /mnt/
total 28
drwxr-xr-x  7 root root 4096 Oct 15 07:42 .
drwxr-xr-x 22 root root 4096 Oct  6 08:31 ..
-rw-r--r--  1 root root    0 Apr  9  2015 .keep
drwxr-xr-x  2 root root 4096 Apr 19  2015 cdrom
drwxr-xr-x  2 root root 4096 Jan 16  2017 floppy
drwxr-xr-x  2 root root 4096 Oct 15 08:07 md0
drwxr-xr-x  2 root root 4096 Apr 17  2015 pendrive
drwxr-xr-x  2 root root 4096 Mar 18  2016 usbstick
root # chown fitzcarraldo:fitzcarraldo /mnt/md0
root # ls -la /mnt/
total 28
drwxr-xr-x  7 root         root         4096 Oct 15 07:42 .
drwxr-xr-x 22 root         root         4096 Oct  6 08:31 ..
-rw-r--r--  1 root         root            0 Apr  9  2015 .keep
drwxr-xr-x  2 root         root         4096 Apr 19  2015 cdrom
drwxr-xr-x  2 root         root         4096 Jan 16  2017 floppy
drwxr-xr-x  2 fitzcarraldo fitzcarraldo 4096 Oct 15 08:07 md0
drwxr-xr-x  2 root         root         4096 Apr 17  2015 pendrive
drwxr-xr-x  2 root         root         4096 Mar 18  2016 usbstick
root # umount /dev/md0

21. ‘Places’ in Dolphin shows /mnt/md0 as ‘7.5 GiB Hard Drive’.

22. I can still mount the RAID from the command line:

root # mount /dev/md0 /mnt/md0
root # df -h /dev/md0
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        7.5G  420M  7.1G   6% /mnt/md0
root # umount /dev/md0

23. If I want to use the RAID in KDE I must use Dolphin to mount it, not mount it from the command line. To do this I click on the RAID ‘7.5 GiB Hard Drive’ listed under ‘Places’, and a window pop-ups prompting me to enter the root user’s password.

If I mount /dev/md0 via Dolphin instead of via the command line, KDE mounts it on a different directory:

root # df -h /run/media/fitzcarraldo/d565c117-37e0-48eb-b635-a2fe70b83272/
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        7.5G  420M  7.1G   6% /run/media/fitzcarraldo/d565c117-37e0-48eb-b635-a2fe70b83272

If I want to unmount it, I right-click on the RAID in ‘Places’ and select ‘Unmount’ in the right-click menu. Once it has been unmounted, I can unplug the hub from the laptop. If I plug the hub back into the laptop, the RAID is detected and can be mounted as usual.

So, it works! A USB hub and pendrives are a handy way to:

  • experiment with creating the various types of RAID;
  • compare the capacity of the RAID with the capacity of the USB pendrives used;
  • measure the time to write and read a large file to/from the RAID and compare those times with the time to write and read the same file to/from a single USB pendrive of the same model.

Firewall zones (profiles) in Linux, and how to switch them automatically if you use UFW

Firstly, a note on terminology: UFW (Uncomplicated Firewall) and its two GUI front-ends Gufw and UFW Frontends use the term ‘application profile’ to refer to a pre-configured set of rules specified in a file. Files containing UFW application profiles are placed in the directory /etc/ufw/applications.d/. An application profile for SMB, for example, enables the root user to use the UFW command ‘ufw allow Samba‘ (‘ufw allow CIFS‘ in Gentoo Linux) rather than having to enter UFW commands specifying the precise ports and network protocols that SMB uses. However, this blog post is not about UFW’s application profiles; it is about what Gufw calls ‘profiles’ and firewalld calls ‘zones’.

In essence a profile/zone is a collection of firewall policies and rules. Both Gufw and firewalld include the concept of a ‘zone’, although Gufw uses the term ‘profile’ rather than ‘zone’. UFW Frontends does not have the concept of a ‘zone’; rules entered via UFW Frontends apply to any network to which you connect your laptop. The ability to define different zones for different networks is handy. For example, you can have certain policies and rules when your laptop is connected to your home network, and different policies and rules when your laptop is connected to the network in a café, hotel, airport or other public place.

An attractive feature of firewalld when used in conjunction with NetworkManager and KDE Plasma is that it is possible to use the desktop environment’s network management module (‘System Settings’ > ‘Connections’) to specify a particular firewalld zone for a particular network connection. For example, let’s say you used firewalld to specify certain policies and rules for a zone you named ‘office’, and you then specified in the System Settings – Connections GUI that a connection named ‘ACM’ should use the zone ‘office’. Thereafter, whenever you connect your laptop to the network named ‘ACM’, firewalld will use the policies and rules you previously configured for the zone ‘office’.

Unlike firewalld, Gufw does not have the ability to switch profiles automatically according to which network the laptop is connected. You have to select manually the profile you wish to use. You would launch Gufw prior to connecting to, for example, your office’s network, select the profile ‘Office’ (or whatever you have named it), then connect your laptop to that network.

I think many people would be satisfied with the functionality currently provided by Gufw. I could use the Gufw GUI to create Gufw profiles with names such as ‘Home’, ‘HomeDave’, ‘Public’, ‘HQoffice’, ‘USoffice’, ‘PestanaRio’ and so on, and specify the different policies and rules I want for each profile. At home I would launch Gufw on my laptop and select the Home profile then connect to my home network; in the office at work I would launch Gufw on my laptop and select the HQoffice profile then connect to the office network; at my friend Dave’s house I would launch Gufw on my laptop and select the HomeDave profile then connect to the house network; and so on. Nevertheless I do see the attraction of automated zone switching, as provided by firewalld in conjunction with NetworkManager and KDE. It would be handy if my laptop could switch automatically to the Home profile when my laptop connected to the network at my home with the name ‘BTHub5-8EUQ’, automatically switch to the HQoffice profile when my laptop connected to the network named ‘HQ-Office2’ in the office, and so on.

I use UFW on my two laptops running Gentoo Linux. The package ufw-frontends is also installed but normally I use UFW directly via the command line. However I wanted to learn about zones/profiles while using UFW, and I also wanted to see if I could automate the switching of zones without resorting to installing firewalld. NetworkManager has the ability to launch ‘hook’ scripts when certain things happen — when a network connection changes, for example — and this seemed to me to be a way of switching profiles automatically.

I had not used Gufw before, so I decided to install it. A package is available in many Linux distributions but there is no ebuild for Gufw in Gentoo’s main Portage tree and I could not find an up-to-date ebuild for it in any Portage overlays. Therefore I created the ebuild for net-firewall/gufw-19.10.0 shown below. It probably needs improving, but it does install a working Gufw in Gentoo Linux.

# Copyright 1999-2019 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

EAPI=7
PYTHON_COMPAT=( python3_{5,6,7} )
DISTUTILS_IN_SOURCE_BUILD=1

inherit distutils-r1

MY_PN="gui-ufw"
MY_PV="$(ver_cut 1-2)"

DESCRIPTION="GUI frontend for managing ufw."
HOMEPAGE="https://gufw.org/"
SRC_URI="https://launchpad.net/${MY_PN}/trunk/${MY_PV}/+download/${MY_PN}-${PV}.tar.gz"

LICENSE="GPL-3"
SLOT="0"
KEYWORDS="~amd64"
IUSE=""

DEPEND="dev-python/python-distutils-extra"
RDEPEND="net-firewall/ufw
	dev-python/netifaces
	dev-python/pygobject:3
	net-libs/webkit-gtk[introspection]
	sys-auth/elogind
	sys-auth/polkit
	x11-libs/gtk+:3[introspection]
	x11-themes/gnome-icon-theme-symbolic
"
S=${WORKDIR}/${MY_PN}-${PV}

pkg_postinst() {
	sed '/dist-packages/d' -i /usr/bin/gufw-pkexec
	sed -E '/\/share\//d' -i /usr/bin/gufw-pkexec
	local PYTHONVERSION="$(python -c 'import sys; print("{}.{}".format(sys.version_info.major, sys.version_info.minor))')"
	sed -E "s|python3\.[0-9]|python${PYTHONVERSION}|g" -i /usr/bin/gufw-pkexec
	sed -E 's|\/lib\/|\/lib64\/|g' -i /usr/bin/gufw-pkexec
}

How To Set Up a Firewall with GUFW on Linux‘ is a good tutorial on Gufw.

As I had not used Gufw previously, I had to play around with it to understand better its functional design. I found that if I configure rules directly via UFW on the command line without using Gufw, Gufw does not allow me to edit those rules (but does allow me to delete them) and those rules exist whichever Gufw profile is selected in the Gufw GUI. Gufw profiles are stored in files named ‘/etc/gufw/*.profile‘ (e.g. /etc/gufw/Home.profile) and these files will not include UFW rules entered via the command line. On the other hand, UFW rules created via the Gufw GUI apply solely to the currently-selected Gufw profile, which is what I would have expected. In other words, I can create a different set of policies and rules in each Gufw profile. Therefore I believe Gufw profiles (as distinct from UFW application profiles) are basically analogous to firewalld’s zones. It also appears to me that Gufw maintains configuration files specifying policies and rules independently of UFW, which Gufw then applies to UFW. In other words, if you are a Gufw user you should not use UFW directly to configure policies and rules, otherwise Gufw’s configuration files will not include what you did directly using UFW. To reiterate, use only Gufw or only UFW, not both.

The current Gufw profile’s name is listed in the file /etc/gufw/gufw.cfg. For example, I currently have the Home profile selected in the Gufw GUI, and the file gufw.cfg contains the following:

[GufwConfiguration]
profile = Home
windowwidth = 542
windowheight = 530
confirmdetelerule = yes

If I examine the contents of the file /etc/gufw/Home.profle I see that it contains the UFW policies and rules I specified for the Gufw Home profile:

[fwBasic]
status = enabled
incoming = deny
outgoing = allow
routed = disabled

[Rule0]
ufw_rule = 137,138/udp ALLOW IN 192.168.1.0/24
description = Samba
command = /usr/sbin/ufw allow in proto udp from 192.168.1.0/24 to any port 137,138
policy = allow
direction = in
protocol = 
from_ip = 192.168.1.0/24
from_port = 
to_ip = 
to_port = 137,138/udp
iface = 
routed = 
logging = 

[Rule1]
ufw_rule = 139,445/tcp ALLOW IN 192.168.1.0/24
description = Samba
command = /usr/sbin/ufw allow in proto tcp from 192.168.1.0/24 to any port 139,445
policy = allow
direction = in
protocol = 
from_ip = 192.168.1.0/24
from_port = 
to_ip = 
to_port = 139,445/tcp
iface = 
routed = 
logging =

I also notice that the other Gufw profiles can differ. For example, my Office.profile file contains the following:

[fwBasic]
status = enabled
incoming = deny
outgoing = allow
routed = allow

The profile name listed in gufw.cfg gets changed when the user changes the profile using the Gufw GUI. It appears to me that only at the point in time when the user selects a certain Gufw profile in the Gufw GUI does Gufw parse the applicable *.profile file and issue commands to UFW to implement the policies and rules specified in the *.profile file.

Initially I tried to automate the process of changing the Gufw profile by doing the following:

  1. I created a NetworkManager Dispatcher hook script to:

    1. detect when the laptop connects to a network;

    2. determine whether the network is at my home, at my workplace or in a public place (café, airport or wherever) by looking at the connection name;

    3. edit gufw.cfg to change the name of the Gufw profile according to the network connected.
  2. I configured KDE to launch Gufw automatically at login, hoping that would implement the Gufw profile specified in gufw.cfg.

When I connected the laptop to various networks, Gufw did indeed show the name of the profile selected by the NetworkManager Dispatcher hook script, but the associated Gufw profile’s rules had not been applied. They were only applied if I clicked on the ‘Profile’ pull-down menu in Gufw, selected a different Gufw profile, then re-selected the desired Gufw profile. Therefore driving Gufw from a NetworkManager Dispatcher hook script is not possible. This is a pity, as Gufw is an easy way to manage UFW from a GUI; it allows the user to create, delete and edit zones (Gufw profiles) and to select them manually. What Gufw doesn’t do is enable the user to associate those zones with connection names, nor trigger specific zone automatically based on the selected network connection. firewalld, on the other hand, does enable the user to do both those things.

As my attempt at automating the switching of zones in Gufw had failed, I decided to create a NetworkManager Dispatcher hook script to switch zones automatically by using UFW commands. Initially I though about creating a bespoke UFW application profile for each zone and allowing/denying those in the script, but it is actually easier to use the fundamental UFW commands in the script, especially as UFW commands are relatively easy to understand. Also, this approach means everything is in a single file, which facilitates configuration. I can simply edit the script in order to: a) add or delete a zone; b) change a zone’s name; c) change policies and rules for a zone; d) add or delete a connection; e) change the name of a connection; f) change the zone a connection uses. Granted, editing a script is not as user-friendly as using the firewalld GUI to configure a zone and then using KDE Plasma’s system settings module Connections to specify that zone for a specific connection, but my script is not particularly difficult to understand and edit. And by using such a script I can continue to use UFW rather than installing firewalld and having to learn how to use it.

My NetworkManager Dispatcher hook script /etc/NetworkManager/dispatcher.d/20_ufw-zones is listed below. In the main body of the script I define the zone I wish to use for each connection, and in the function select_zone I define the policies and rules I want each zone to use.

#!/bin/bash
INTERFACE=$1
STATUS=$2
WIRED=enp4s0f1
WIFI=wlp3s0

CT_helper_rule() {
    echo "# The following is needed to enable Samba commands to" >> /etc/ufw/before.rules
    echo "# work properly for broadcast NetBIOS name resolution" >> /etc/ufw/before.rules
    echo "#"  >> /etc/ufw/before.rules
    echo "# raw table rules" >> /etc/ufw/before.rules
    echo "*raw" >> /etc/ufw/before.rules
    echo ":OUTPUT ACCEPT [0:0]" >> /etc/ufw/before.rules
    echo "-F OUTPUT" >> /etc/ufw/before.rules
    echo "-A OUTPUT -p udp -m udp --dport 137 -j CT --helper netbios-ns" >> /etc/ufw/before.rules
    echo "COMMIT" >> /etc/ufw/before.rules
}
 
select_zone() {
    ufw --force reset
    ufw --force enable
    ZONE=$1
    case "$ZONE" in
    'Home')
        ufw default deny incoming
        ufw default allow outgoing
        #
        # Rules for SMB
        ufw allow from 192.168.1.0/24 to any port 137,138 proto udp
        ufw allow from 192.168.1.0/24 to any port 139,445 proto tcp
        CT_helper_rule
        #
        # Rules for KDEConnect
        ufw allow from 192.168.1.0/24 to any port 1714:1764 proto udp
        ufw allow from 192.168.1.0/24 to any port 1714:1764 proto tcp
    ;;
    'Office')
        ufw default deny incoming
        ufw default allow outgoing
    ;;
    'Public')
        ufw default reject incoming
        ufw default allow outgoing
    ;;
    'JohnsHouse')
        ufw default deny incoming
        ufw default allow outgoing
        #
        # Rules for SMB
        ufw allow from 192.168.42.0/24 to any port 137,138 proto udp
        ufw allow from 192.168.42.0/24 to any port 139,445 proto tcp
        CT_helper_rule
        #
        # Rules for KDEConnect
        ufw allow from 192.168.42.0/24 to any port 1714:1764 proto udp
        ufw allow from 192.168.42.0/24 to any port 1714:1764 proto tcp
    ;;
    esac
    ufw --force reload
    rm /etc/ufw/*.rules.20* # Delete backups of *.rules files ufw makes every time it is reset
    echo -n `date +"[%F %T %Z]"` >> /var/log/ufw-zones.log
    echo " Zone $ZONE selected for connection $ACTIVE on interface $INTERFACE." >> /var/log/ufw-zones.log
}
 
# Check if either the wired or wireless interface is up
if [ "$INTERFACE" = "$WIRED" -o "$INTERFACE" = "$WIFI" ] && [ "$STATUS" = "up" ]; then
 
    # Check if a single connection is active
    if [ `nmcli c | grep -v "\-\-" | grep -v "NAME.*UUID.*TYPE.*DEVICE" | wc -l` -eq 1 ]; then
 
        # Ascertain the name of the active connection
        ACTIVE=`nmcli c | grep -v "\-\-" | grep -v "NAME.*UUID.*TYPE.*DEVICE" | awk -F' ' '{print $1}'`
 
        case "$ACTIVE" in
 
        'eth0')
            ZONE="Home"
        ;;
        'POR1-wired')
            ZONE="Office"
        ;;
        'BTHub5-8EUQ')
            ZONE="Home"
        ;;
        'BTHub5-8EUQ-5GHz')
            ZONE="Home"
        ;;
        'John1')
            ZONE="JohnsHouse"
        ;;
        'GRAND MERCURE')
            ZONE="Public"
        ;;
        *)
            # If connection name is not in above list
            ZONE="Public"
        ;;

        esac

        select_zone $ZONE
        exit $?

    fi
fi

The log file that the script uses contains a chronological record of the connections made and the zones selected:

$ cat /var/log/ufw-zones.log 
[2019-09-30 20:13:52 BST] Zone Home selected for connection eth0 on interface enp4s0f1.
[2019-10-01 22:59:18 BST] Zone Home selected for connection BTHub5-8EUQ-5GHz on interface wlp3s0.
[2019-10-02 17:59:23 EDT] Zone Public selected for connection loganwifi on interface wlp3s0.
[2019-10-03 10:12:46 EDT] Zone Office selected for connection POR1-wired on interface enp4s0f1.

Paul Gideon Dann’s patchset for Poppler to enable Okular (Qt5) to use Cairo rather than Splash to render PDF files

If you view the same PDF file in Okular (KDE) and Evince (GNOME), you may notice that fonts and lines are rendered better in Evince. Both applications use Poppler to render text and graphics in PDF files, but Poppler uses a different rendering backend in the two applications. For Evince Poppler uses the Cairo library, whereas for Okular Poppler uses Splash, a backend inherited from Poppler’s predecessor Xpdf (still in development). Unfortunately for KDE users, Cairo often does a better job than Splash. However, independent software engineer Paul Gideon Dann came to the rescue by producing the patchset poppler-cairo-backend to modify Poppler in order to make it use the Cairo library instead of Splash when Poppler is used by Okular. To quote the README file for Paul’s patchset:

Purpose of this Patchset

Currently, the default backend for the Qt5 wrapper (used by Okular) is Splash. Unfortunately, Splash does not support subpixel rendering of fonts, so those of us using KDE are stuck with somewhat ugly-looking fonts. This patchset adds support for the Cairo backend to the Qt5 wrapper. It also forces subpixel rendering in the Cairo backend. The upshot of this is that we get beautiful fonts in Okular.

The README focuses on fonts, but in fact the rendering of lines in graphics in PDF files can also be improved by the application of the patchset.

Apparently the Poppler maintainer feels that the introduction of a dependency on Cairo to the Qt5 wrapper (even an optional dependency) in Poppler would be controversial, and he is not willing to merge the patchset. For Okular users who already have Cairo installed (e.g. for Firefox, Inkscape, Scribus and so on), and who are noticing inadequate rendering of some PDF files, Paul’s patchset is worth trying.

In Gentoo Linux, which is a source code-based distribution, it is very easy to apply the patchset. For example, I did the following to apply the patchset for Poppler 0.80.0 in a ~amd64 (Testing Branch) installation:

1. Created a package-specific and version-specific directory to hold the patchset:

root # mkdir -p /etc/portage/patches/app-text/poppler-0.80.0

2. Downloaded the patchset for Poppler 0.80.0 from the following Web page:

https://github.com/giddie/poppler-cairo-backend/tree/76e607bcf010d6d9b8df5cb0f851ef9c91d4caf2

3. Copied the patchset to the directory created in Step 1:

root # cp /home/fitzcarraldo/Downloads/*.patch /etc/portage/patches/app-text/poppler-0.80.0/
root # ls -1 /etc/portage/patches/app-text/poppler-0.80.0
0001-Cairo-backend-added-to-Qt5-wrapper.patch
0002-Setting-default-Qt5-backend-to-Cairo.patch
0003-Apply-subpixel-rendering-in-Cairo-Backend.patch

4. Checked first that the patchset could be applied successfully before actually using it:

root # cd /usr/portage/app-text/poppler
root # ebuild poppler-0.80.0.ebuild clean prepare
 * poppler-0.80.0.tar.xz BLAKE2B SHA512 size ;-) ...                                     [ ok ]
 * checking ebuild checksums ;-) ...                                                     [ ok ]
 * checking auxfile checksums ;-) ...                                                    [ ok ]
 * checking miscfile checksums ;-) ...                                                   [ ok ]
>>> Unpacking source...
>>> Unpacking poppler-0.80.0.tar.xz to /var/tmp/portage/app-text/poppler-0.80.0/work
>>> Source unpacked in /var/tmp/portage/app-text/poppler-0.80.0/work
>>> Preparing source in /var/tmp/portage/app-text/poppler-0.80.0/work/poppler-0.80.0 ...
 * Applying poppler-0.60.1-qt5-dependencies.patch ...                                    [ ok ]
 * Applying poppler-0.28.1-fix-multilib-configuration.patch ...                          [ ok ]
 * Applying poppler-0.78.0-respect-cflags.patch ...                                      [ ok ]
 * Applying poppler-0.61.0-respect-cflags.patch ...                                      [ ok ]
 * Applying poppler-0.57.0-disable-internal-jpx.patch ...                                [ ok ]
 * Applying 0001-Cairo-backend-added-to-Qt5-wrapper.patch ...                            [ ok ]
 * Applying 0002-Setting-default-Qt5-backend-to-Cairo.patch ...                          [ ok ]
 * Applying 0003-Apply-subpixel-rendering-in-Cairo-Backend.patch ...                     [ ok ]
 * User patches applied.
>>> Source prepared.

5. Re-merged Poppler to apply the patchset to the Poppler source code and rebuild the patched package:

root # emerge -1v poppler

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R    ] app-text/poppler-0.80.0:0/90::gentoo  USE="cairo cjk cxx introspection jpeg jpeg2k lcms png qt5 tiff utils -curl -debug -doc -nss" 0 KiB

Total: 1 package (1 reinstall), Size of downloads: 0 KiB

>>> Verifying ebuild manifests
>>> Emerging (1 of 1) app-text/poppler-0.80.0::gentoo
>>> Installing (1 of 1) app-text/poppler-0.80.0::gentoo
>>> Jobs: 1 of 1 complete                           Load avg: 1.06, 1.11, 0.95
>>> Auto-cleaning packages...

>>> No outdated packages were found on your system.

 * GNU info directory index is up-to-date.

6. Re-merged Okular so that it uses the patched Poppler dependency:

root # emerge -1v okular

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R    ] kde-apps/okular-19.08.1:5::gentoo  USE="chm crypt djvu image-backend pdf postscript tiff -debug -epub -handbook -markdown -mobi -mobile -plucker -share -speech -test" 0 KiB

Total: 1 package (1 reinstall), Size of downloads: 0 KiB

>>> Verifying ebuild manifests
>>> Emerging (1 of 1) kde-apps/okular-19.08.1::gentoo
>>> Installing (1 of 1) kde-apps/okular-19.08.1::gentoo
>>> Jobs: 1 of 1 complete                           Load avg: 1.17, 1.13, 1.04
>>> Auto-cleaning packages...

>>> No outdated packages were found on your system.

 * GNU info directory index is up-to-date.

My thanks go to Paul for taking the time to produce the patchset.

How to run KDE Dolphin, Kate and KWrite as root user

When using KDE I occasionally wish to launch KWrite or Kate as root user in order to edit system files more easily than using a TUI editor in a terminal window (either launched as root user or by using the sudoedit command). Being able to browse using Dolphin as the root user occasionally is also useful. These all used to be possible by launching the application with the kdesu command, but in 2017 KDE developer Martin Gräßlin removed this option on security grounds (see his blog post ‘Editing files as root‘). Attempting to launch e.g. Kate using the sudo command results in the following message:

$ sudo kate
Executing Kate with sudo is not possible due to unfixable security vulnerabilities.

Attempting to launch e.g. Kate using the kdesu command results in a pop-up window prompting me to enter the root user’s password, but then does not launch Kate:

$ kdesu kate
$

I am willing to accept a small risk despite the ‘unfixable security vulnerabilities’ , and a 2018 Kubuntu Forums post by KDE user Rog131 provided me with a solution. It is possible to launch Dolphin, Kate and KWrite as root from your user account by using the pkexec command. For example, to launch Dolphin you can enter:

$ pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true dolphin

Dolphin first displays an orange-coloured box with the warning message ‘Running Dolphin as root can be dangerous. Please be careful.’ and you can then browse and open root-owned directories and files.

You can also launch Kate and KWrite as root from your user account in the same way:

$ pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true kate
$ pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true kwrite

To make it easy to launch them as root user from e.g. Konsole or Yakuake you could set aliases for the three commands in your ~/.bashrc file:

$ tail -n 3 ~/.bashrc
alias dolroot="pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true dolphin"
alias kateroot="pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true kate"
alias kwriteroot="pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true kwrite"

Then all you would need to type in a terminal window would be:

$ dolroot
$ kateroot
$ kwriteroot

which are no more difficult than having to type:

$ kdesu dolphin
$ kdesu kate
$ kdesu kwrite

If an alias is used, rooted-Dolphin/Kate/KWrite can be launched from the command line but cannot be launched via KDE’s Application Launcher menu or KRunner. On the other hand, if a wrapper script is used, rooted-Dolphin/Kate?KWrite can be launched from the user’s command line and via KDE’s Application Launcher menu (and therefore via KRunner too). For example, I created three tiny Bash scripts dolroot, kateroot and kwriteroot. The scripts simply contain the aforementioned pkexec command. For example, dolroot contains:

#!/bin/bash
pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true dolphin

Don’t forget to make them executable:

$ chmod 700 dolroot
$ chmod 700 kateroot
$ chmod 700 kwriteroot
$ ls -la *root
-rwx------ 1 fitzcarraldo fitzcarraldo 115 Jul 30 15:33 dolroot
-rwx------ 1 fitzcarraldo fitzcarraldo 112 Jul 30 15:34 kateroot
-rwx------ 1 fitzcarraldo fitzcarraldo 114 Jul 30 15:34 kwriteroot	

After adding entries for dolroot, kateroot and kwriteroot to the KDE Application Launcher’s menu, you can press Alt+F2 as usual to display the KRunner launcher then enter ‘dolroot’, ‘kateroot’ or ‘kwriteroot’ (without the quotes, obviously) in the KRunner window to launch Dolphin/Kate/KWrite as root user. A window will pop-up for you to enter the root user’s password. Once you have entered the root user’s password, the application will be launched.

Thankfully KDE’s Nathaniel Graham is pragmatic:

D12795 – Re-allow running Dolphin as the root user (but still not using sudo)
D12732 – Show a warning when running as the root user

How to change the height of the Kickoff Application Launcher menu in KDE Plasma

The height of the KDE Plasma Kickoff Application Launcher menu is not user-configurable, which is odd in a Desktop Environment with a reputation for being highly user-configurable.

It turns out that the height and width of the pop-up menu are hard-coded in the ASCII file /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml:

root # grep -E "Layout.minimumHeight.*units.gridUnit" /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml
    Layout.minimumHeight: units.gridUnit * 34
root # grep -E "Layout.minimumWidth.*units.gridUnit" /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml
    Layout.minimumWidth: units.gridUnit * 26

Now, I was a bit fed up having to scroll up and down the launcher menu to see all fourteen entries in my Favourites list, so I decided to increase the height of the menu, which I did by editing /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml as root user:

root # nano /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml
root # grep -E "Layout.minimumHeight.*units.gridUnit" /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml
    Layout.minimumHeight: units.gridUnit * 44

The only downside to this is that the file will be overwritten when the package kde-plasma/plasma-desktop is upgraded.

The following command would allow me to make sure the file contains the height value of ’44’ that I want:

root # sed -i '/Layout.minimumHeight: units.gridUnit/ c\    Layout.minimumHeight: units.gridUnit * 44' /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml

Therefore, to automate the editing of the file in my Gentoo installations that use OpenRC I created a shell script /etc/local.d/50-set_Kickoff_height.start with the following contents:

#!/bin/bash
if [ -e /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml ]; then
    sed -i '/Layout.minimumHeight: units.gridUnit/ c\    Layout.minimumHeight: units.gridUnit * 44' /usr/share/plasma/plasmoids/org.kde.plasma.kickoff/contents/ui/FullRepresentation.qml
fi

The FullRepresentation.qml file will then be edited every time the machine boots, which is a tad inefficient but not a big overhead.

This is not a perfect solution because the menu will revert to its default height following an upgrade to the package kde-plasma/plasma-desktop until I reboot the machine, but it is good enough for me.

KDE Device Notifier work-around

KDE Device Notifier can be annoying sometimes. The problem is that clicking on the Eject icon in Device Notifier (tooltip ‘Click to safely remove this device’) both unmounts and ejects the device (two separate commands). Of course, in the case of a USB device the device remains physically connected until you pull out the USB plug. You cannot re-mount the device in KDE Device Notifier until you unplug it and plug it in again. However, there is a hack that can help somewhat, as I explain below.

Firstly, note that it is possible to mount and unmount drives by using the ‘udisksctl’ command. For example, consider one of my USB HDDs which has the label ‘USBHDD01’ (I assign a label to all HDD partitions, be they on internal HDDs or on external HDDs/pendrives). It is possible to unmount the specific USB device and remount it by using the following commands:

fitzcarraldo@clevow230ss ~ $ udisksctl unmount -b /dev/disk/by-label/USBHDD01
Unmounted /dev/sdb1.
fitzcarraldo@clevow230ss ~ $ udisksctl mount -b /dev/disk/by-label/USBHDD01
Mounted /dev/sdb1 at /run/media/fitzcarraldo/USBHDD01.

In both the above cases the USB device remains visible in Device Notifier. I have created a couple of executable Desktop Configuration Files in the directory ~/Desktop/ which I can double-click to run each of the above commands. I have given each of them an appropriate icon:

The file ~/Desktop/Mount_USBHDD01.desktop contains the following:

[Desktop Entry]
Comment[en_GB]=Mount USB HDD with label USBHDD01
Comment=Mount USB HDD with label USBHDD01
Exec=udisksctl mount -b /dev/disk/by-label/USBHDD01
GenericName[en_GB]=Mount_USBHDD01
GenericName=Mount_USBHDD01
Icon=media-mount
MimeType=
Name[en_GB]=Mount_USBHDD01
Name=Mount_USBHDD01
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

The file ~/Desktop/Unmount_USBHDD01.desktop contains the following:

[Desktop Entry]
Comment[en_GB]=Unmount USB HDD with label USBHDD01
Comment=Unmount USB HDD with label USBHDD01
Exec=udisksctl unmount -b /dev/disk/by-label/USBHDD01
GenericName[en_GB]=Unmount_USBHDD01
GenericName=Unmount_USBHDD01
Icon=media-eject
MimeType=
Name[en_GB]=Unmount_USBHDD01
Name=Unmount_USBHDD01
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

(N.B. Since I could not find a media-unmount icon, I have used the media-eject icon to represent Unmount.)

This is not perfect in the sense that the device will still disappear from Device Notifier if you click on the Eject icon in Device Notifier. But at least I can avoid doing that until I really do want to unplug the device from my laptop. In other cases I simply double-click on the Mount_USBHDD01 icon and Unmount_USBHDD01 icon on my Desktop to mount and unmount the USB device as many times as I need to.

HEIC image files in Linux

I was at an event recently where the attendees were asked to upload their camera and smartphone photos and videos to a shared Google Drive folder. Some of the uploaded photo files have a .HEIC (High Efficiency Image Container) extension, which I had not come across before. I have since learnt that these HEIC files were produced by iPhones running iOS 11, encoded using the HEIF (High Efficiency Image File) format. Apparently the HEIF format is superior to the JPEG format in a number of ways (see the links at the end of my post, especially the image examples given by Nokia), although it is subject to patents and therefore I believe there are certain constraints to coding image files in HEIC format. Anyway, I’ll leave you to read the fine print. My interest was simply because I wanted to be able to download the above-mentioned photo files and view them all in the file managers and image-viewing applications in Linux and Android on my various devices.

Now, I can browse and view the above-mentioned shared HEIC images in Google Drive in the Firefox and Chrome browsers in Linux, although an ownCloud site viewed using the same browsers displays the HEIC files as grey icons that can only be downloaded, not opened and viewed in the browser. I also found that Cirrus, the Android app for ownCloud that I use on my Galaxy Note 8 phone, cannot display HEIC photos either.

I downloaded the HEIC files to a machine running Lubuntu 18.04 and to a machine running Gentoo Linux. The file manager PCManFM in Lubuntu 18.04 displays grey icons rather than thumbnails for these HEIC files, and KDE’s Dolphin 18.08.3 file manager in Gentoo Linux displays green image icons rather than thumbnails for them. As far as Linux image viewers go, in Lubuntu 18.04 I find that GPicView 0.2.5 and Geeqie 1.4 cannot display HEIC images, and in Gentoo Linux KDE I find that GQview 2.1.5-r1, Okular 18.08.3 and Gwenview 18.08.3 cannot display HEIC images. So I set about converting all the HEIC files to JPG files. I managed to do this but needed to use a range of tools, as illustrated by a couple of examples below for Lubuntu 18.04 and Gentoo Linux. This post might seem long-winded but perhaps may be of help to Linux users coming across .HEIC files for the first time.

From the .HEIC files I had downloaded I picked one at random to try and convert to a JPG file: IMG_3706.HEIC. Its EXIF data confirms it is an HEIC file:

user $ exiftool IMG_3706.HEIC | grep "File Type"
File Type                       : HEIC
File Type Extension             : heic
user $ exiftool IMG_3706.HEIC | grep "Camera Model"
Camera Model Name               : iPhone 7 Plus

Several of the files with the .HEIC suffix that I downloaded were not real HEIC files according to their EXIF data:

user $ exiftool IMG_9474.HEIC | grep "File Type"
File Type                       : JPEG
File Type Extension             : jpg
user $ exiftool IMG_9474.HEIC | grep "Camera Model"
Camera Model Name               : iPhone 8

Those files were apparently treated as JPEG files by the tools I mention below, so I have omitted the results for those ‘false’ HEIC files.

Lubuntu 18.04

1. I installed the libheif example tools:

user $ sudo apt install libheif-examples

2. I used the heif-info command to check the file:

user $ heif-info IMG_3706.HEIC 
image: 3024x4032 (id=49), primary
  thumbnail: 240x320
  alpha channel: no
  depth channel: no

3. I tried to convert the file using the heif-convert command:

user $ heif-convert IMG_3706.HEIC IMG_3706.jpg
File contains 1 images
Written to IMG_3706.jpg

4. Apparently Imagemagick >=7.0.7-22 compiled with --with-libheif is supposed to be able to convert HEIC files to JPG. Anyway, I tried to convert the file using the current version of Imagemagick in Lubuntu 18.04 (the current package version is 8:6.9.7.4+dfsg-16ubuntu6.4):

user $ convert IMG_3706.HEIC IMG_3706a.jpg
convert-im6.q16: no decode delegate for this image format `HEIC' @ error/constitute.c/ReadImage/504.
convert-im6.q16: no images defined `IMG_3706a.jpg' @ error/convert.c/ConvertImageCommand/3258.

5. Apparently the GIMP >=2.10.2 supports HEIF by using heif-gimp-plugin. Anyway, I tried to open the file with the current version of the GIMP in Lubuntu 18.04 (the current package version is 2.8.22-1). The GIMP launches and pops-up a window with the title ‘GIMP Message’ containing the following message and an ‘OK’ button:

GIMP Message
Opening /home/fitzcarraldo/IMG_3706.HEIC’ failed: Unknown file type

6. I used the online tool ‘libheif decoder demo’ (https://strukturag.github.io/libheif/) in a browser window. This can load the file IMG_3706.HEIC (‘Browse…’ button) and convert it (‘Save image…’ button) to IMG_3706.jpeg.

Gentoo Linux with KDE 5

1. I installed the libheif example tools implicitly by re-merging Imagemagick with USE="heif", which installs libheif.

root # cat /etc/portage/package.use/imagemagick 
media-gfx/imagemagick heif
root # emerge imagemagick

2. I used the heif-info command to check the file:

user $ heif-info IMG_3706.HEIC  
image: 3024x4032 (id=49), primary
  thumbnail: 240x320
  alpha channel: no
  depth channel: no

3. I tried to convert the file using the heif-convert command:

user $ heif-convert IMG_3706.HEIC IMG_3706.jpg
File contains 1 images
Written to IMG_3706.jpg

4. I tried to convert the file using Imagemagick >=7.0.7-22 compiled with --with-libheif (Imagemagick merged with USE="heif"):

user $ convert IMG_3706.HEIC IMG_3706a.jpg
user $

So Imagemagick 7.0.8.16 in Gentoo has no trouble with the file IMG_3706.HEIC.

5. I tried to open the file with the GIMP >=2.10.2, which supports HEIF using heif-gimp-plugin (GIMP >=2.10.6-r1 with USE="heif" in the case of Gentoo Linux)

First I re-merged the GIMP with the heif USE flag:

root # cat /etc/portage/package.accept_keywords/gimp
=media-gfx/gimp-2.10.8-r1 ~amd64
# required by media-gfx/gimp-2.10.8-r1::gentoo
=media-libs/libmypaint-1.3.0 ~amd64
# required by media-gfx/gimp-2.10.8-r1::gentoo
=media-gfx/mypaint-brushes-1.3.0-r1 ~amd64
# required by media-gfx/gimp-2.10.8-r1::gentoo
=media-libs/gegl-0.4.12 ~amd64
# required by media-gfx/gimp-2.10.8-r1::gentoo
=media-libs/babl-0.1.60 ~amd64
root # cat /etc/portage/package.use/gimp
media-gfx/gimp heif
root # emerge -1vp gimp

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N    ~] media-gfx/mypaint-brushes-1.3.0-r1:1.0::gentoo  2,390 KiB
[ebuild     U ~] media-libs/babl-0.1.60::gentoo [0.1.38::gentoo] USE="(-altivec)" CPU_FLAGS_X86="mmx sse sse2 sse3%* sse4_1 -f16c" 670 KiB
[ebuild  N     ] media-libs/gexiv2-0.10.8::gentoo  USE="-introspection -python -static-libs -test -vala" PYTHON_TARGETS="python2_7 python3_6 -python3_4 -python3_5" 620 KiB
[ebuild  NS   ~] media-libs/gegl-0.4.12:0.4::gentoo [0.2.0-r5:0::gentoo] USE="cairo ffmpeg introspection lcms openexr sdl svg tiff v4l -debug -jpeg2k -lensfun -libav -raw -test -umfpack -vala -webp" CPU_FLAGS_X86="mmx sse" 6,900 KiB
[ebuild  NS    ] media-libs/gegl-0.3.26:0.3::gentoo [0.2.0-r5:0::gentoo] USE="cairo ffmpeg introspection lcms openexr sdl svg tiff v4l -debug -jpeg2k -lensfun -raw -test -umfpack -vala -webp" CPU_FLAGS_X86="mmx sse" 6,378 KiB
[ebuild  N    ~] media-libs/libmypaint-1.3.0::gentoo  USE="gegl nls openmp -introspection" 428 KiB
[ebuild     U ~] media-gfx/gimp-2.10.8-r1:2::gentoo [2.8.22-r1:2::gentoo] USE="alsa heif%* mng openexr%* udev wmf -aalib (-altivec) (-aqua) -debug -doc -gnome -jpeg2k -postscript -python -smp -test -unwind% -vector-icons% -webp% -xpm (-bzip2%*) (-curl%) (-dbus%*) (-exif%*) (-jpeg%*) (-lcms%*) (-pdf%*) (-png%*) (-svg%*) (-tiff%*)" CPU_FLAGS_X86="mmx sse" PYTHON_TARGETS="python2_7" 31,206 KiB

Total: 7 packages (2 upgrades, 3 new, 2 in new slots), Size of downloads: 48,591 KiB

I then launched the GIMP and successfully opened the file IMG_3706.HEIC, and I was able to export it as IMG_3706.jpg.

6. As would be expected, the online tool ‘libheif decoder demo’ (https://strukturag.github.io/libheif/) behaves exactly the same in Gentoo Linux as it does in Lubuntu 18.04 (see earlier).

Summary

So there you have it; if the Linux file manager and/or image viewing applications you use cannot already handle HEIC files, the tools in Linux that I found may work are as follows:

  • heif-convert (from the package libheif-examples in Ubuntu/Lubuntu, or from from the package libheif in Gentoo).
  • Imagemagick (not every version).
  • The GIMP (not every version).
  • the online tool ‘libheif decoder demo’ (https://strukturag.github.io/libheif/).

I have not tried the copyright open-source code from Nokia (see link under Further Reading below), qt-heif-image-plugin and tifig (not in active development). If you have had success using another tool to convert HEIC files, please post a comment below for the benefit of other users, giving the name of the tool, the package name and version, and the Linux distribution (including release number, if not a rolling distribution).

Further reading

  1. Wikipedia – High Efficiency Image File Format
  2. Lifewire – What Are HEIF and HEIC, and Why Is Apple Using Them?
  3. Nokia – High Efficiency Image File Format (HEIF)
  4. libheif – a ISO/IEC 23008-12:2017 HEIF file format decoder and encoder
  5. askubuntu – Any app on Ubuntu to open HEIF (.heic, High Efficiency Image File Format) pictures?

Installing Dropbox in Gentoo Linux following the recent restrictions introduced for Dropbox for Linux

In a 2013 post I explained how I installed Dropbox in Gentoo Linux running KDE 4. The Dropbox company has recently imposed some restrictions in the Linux client, so this is to explain what I did to get Dropbox working again in my two Gentoo Linux installations, both using the ext4 filesystem (unencrypted) and, these days, KDE Plasma 5.

Both my laptops running Gentoo Linux had a version of Dropbox installed via the Portage package manager: dropbox-45.3.88 in the case of the laptop running Gentoo amd64, and dropbox-48.3.56 in the case of the laptop running Gentoo ~amd64. Recently a Dropbox window popped up, warning me to upgrade Dropbox to the latest version within seven days otherwise the client would no longer be able to sync with the remote Dropbox server. I also received an e-mail from the Dropbox company titled ‘[Action required] We’re updating Linux system requirements‘ informing me that the only supported Linux distributions from now on would be Ubuntu 14.04 or higher and Fedora 21 or higher, and furthermore that the client will only work on an unencrypted ext4 filesystem. As both my Gentoo installations use unencrypted ext4, I was OK on that score, but I still had the problem that an up-to-date Dropbox ebuild is not available for Gentoo and the old Dropbox versions I was using no longer sync. However, I managed to install the latest version of Dropbox (currently 55.4.171) in Gentoo, and it works fine. The Dropbox client’s icon is on the KDE Plasma 5 Panel, and the local Dropbox directory is being sync’ed correctly. Below I explain what I did.

1. I selected ‘Quit Dropbox’ from the old Dropbox client’s menu, and the Dropbox icon disappeared from the Panel.

2. I removed the Dropbox daemon from the list of script files to be started at login (‘System Settings’ > ‘Startup and Shutdown’ > ‘Autostart’).

3. I unmerged (uninstalled) the dropbox package:

clevow230ss /home/fitzcarraldo # emerge --ask --depclean dropbox

4. I deleted the directories ~/.dropbox and ~/.dropbox-dist but kept the directory ~/Dropbox and its contents.

fitzcarraldo@clevow230ss ~ $ rm -rf ~/.dropbox ~/.dropbox-dist

5. I followed the instructions under ‘Dropbox Headless install via command line‘ on the Dropbox Website to re-install the latest version of the daemon and client:

fitzcarraldo@clevow230ss ~ $ cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf -

6. I configured KDE Plasma 5 to start ~/.dropbox-dist/dropboxd at login (‘System Settings’ > ‘Startup and Shutdown’ > ‘Autostart’ > ‘Add Script…’).

7. I launched ~/.dropbox-dist/dropboxd manually from a Konsole window. The Dropbox client icon appeared on the Panel and I was prompted to login to my Dropbox account via a Web browser, as per the instructions on the Dropbox Website (see link in in Step 5):

If you’re running Dropbox on your server for the first time, you’ll be asked to copy and paste a link in a working browser to create a new account or add your server to an existing account. Once you do, your Dropbox folder will be created in your home directory.

8. I logged in to my Dropbox account via the Firefox browser. As soon as I had logged in via the browser, a message appeared in the browser window informing me that “Your computer was successfully linked to your account”, and the Dropbox client icon appeared on the Panel and showed that the contents of ~/Dropbox were being synchronised.

Everything seems to be working as before. The Dropbox icon on the Panel has the same menu items it had previously. ‘Preferences…’ shows the Dropbox version as v55.4.171. I have not ticked ‘Start Dropbox on system startup’ under Dropbox Preferences because I configured automatic startup using KDE Plasma 5 ‘System Settings’ as described in Step 6 above, and the Dropbox daemon is indeed started automatically when I login.

The Dropbox Website’s instructions (see link in Step 5) also include the following:

Download this Python script to control Dropbox from the command line. For easy access, put a symlink to the script anywhere in your PATH.

I did download that Python script and made it executable:

fitzcarraldo@clevow230ss ~/Dropbox $ chmod +x dropbox.py

However the Python 3.6 interpreter in my Gentoo Linux installations report a syntax error in the script when I run it, I assume because it was written for a different version of Python:

fitzcarraldo@clevow230ss ~/Dropbox $ ./dropbox.py 
  File "./dropbox.py", line 233
    except OSError, e:
                  ^
SyntaxError: invalid syntax

Anyway, as the Dropbox client icon is on the KDE Plasma 5 Panel and I can control Dropbox from there, I see no need for the Python script.

9. My Gentoo installations have a Bash script ~/dbox.sh that I had created to be launched by a Desktop Configuration file ~/Desktop/Dropbox.desktop with a nice icon which I double-click on if I want to relaunch the Dropbox daemon (if I previously quit Dropbox from the client’s menu, for example). I had to modify ~/dbox.sh by replacing the command ‘dbus-launch dropbox start > /dev/null‘ with the command ‘/home/fitzcarraldo/.dropbox-dist/dropboxd‘ as shown below.

dbox.sh

#!/bin/bash
notify-send 'Launching Dropbox' 'Daemon will be (re)started in 20 seconds' --icon=dialog-information
sleep 20s
ps auxww | awk '$0~/dropbox/&&$0!~/awk/{print $2}' | xargs kill
/home/fitzcarraldo/.dropbox-dist/dropboxd

Dropbox.desktop

[Desktop Entry]
Comment[en_GB]=(re)launch Dropbox daemon
Comment=(re)launch Dropbox daemon
Exec=/home/fitzcarraldo/dbox.sh
GenericName[en_GB]=Dropbox
GenericName=Dropbox
Icon=kipi-dropbox
MimeType=
Name[en_GB]=Dropbox
Name=Dropbox
Path=
StartupNotify=true
Terminal=false
TerminalOptions=
Type=Application
X-DBUS-ServiceName=
X-DBUS-StartupType=none
X-KDE-SubstituteUID=false
X-KDE-Username=fitzcarraldo

10. At the moment Dropbox is working fine again in my Gentoo installations. However, I noticed that Gentoo Linux user zsitvaij posted the following comment in a Gentoo Forums thread:

On every dropbox update, I have to remove ~/.dropbox-dist/dropbox-lnx./libdrm.so.2 to avoid having it crash on launch, works fine after until they update again.

I do not know if that will be necessary in my case, as I have not yet had to upgrade Dropbox from the Version 55.4.171 that I recently installed. When a new version of Dropbox becomes available I will update this post to confirm whether or not I had to do anything to keep Dropbox working.

Addendum (5 October 2019): With reference to my addendum of 31 August 2018, the Python script dropbox.py that can be downloaded from the Dropbox Web site has been updated and is now written in Python 3, so you can ignore my addendum of 31 August 2018.

Addendum (1 October 2018): With reference to my addendum of 2 September 2018, if you are using OpenRC it is possible to automate the deletion of the file ~/.dropbox-dist/dropbox-lnx.x86_64-/libdrm.so.2 by creating a Bash script /etc/local.d/40dropbox.start containing the following:

#!/bin/bash
if [ -e /home/fitzcarraldo/.dropbox-dist/dropbox-lnx.x86_64-*/libdrm.so.2 ]
then
    rm /home/fitzcarraldo/.dropbox-dist/dropbox-lnx.x86_64-*/libdrm.so.2
fi

Replace my username with your username, obviously. Of course the conditional test could be dispensed with and the script could just contain the shebang line and the rm line, which would still work even if the file does not exist, but it feels a bit tidier to only attempt to delete the file if it actually exists.

Addendum (2 September 2018): I have just installed Dropbox Version 56.4.94 in my Gentoo ~amd64 installation and I had to use the command shown below once in order to stop the daemon segfaulting when I entered the command ~/.dropbox-dist/dropboxd in a Konsole window:

fitzcarraldo@clevow230ss ~/Dropbox $ rm ~/.dropbox-dist/dropbox-lnx.x86_64-56.4.94/libdrm.so.2

Addendum (31 August 2018): The Python script dropbox.py that can be downloaded from the Dropbox Web site (see Step 8 above) is old, as can be seen in the comments in the header of the script:

# Dropbox frontend script
# This file is part of nautilus-dropbox 2015.10.28.

It is written in Python 2. Although I do not need to use it, I managed to get it to run in my Gentoo installations by replacing the shebang line ‘#!/usr/bin/python‘ with ‘#!/usr/bin/env python2‘. This works in my Gentoo installations because they have both Python 2.7 and Python 3.6 installed. When I now run dropbox.py I see the following:

fitzcarraldo@clevow230ss ~/Dropbox $ ./dropbox.py 
Dropbox command-line interface

commands:

Note: use dropbox help  to view usage for a specific command.

 status       get current status of the dropboxd
 throttle     set bandwidth limits for Dropbox
 help         provide help
 stop         stop dropboxd
 running      return whether dropbox is running
 start        start dropboxd
 filestatus   get current sync status of one or more files
 ls           list directory contents with current sync status
 autostart    automatically start dropbox at login
 exclude      ignores/excludes a directory from syncing
 lansync      enables or disables LAN sync
 sharelink    get a shared link for a file in your dropbox
 proxy        set proxy settings for Dropbox

fitzcarraldo@clevow230ss ~/Dropbox $ ./dropbox.py status
Up to date
fitzcarraldo@clevow230ss ~/Dropbox $ ./dropbox.py running
fitzcarraldo@clevow230ss ~/Dropbox $ ./dropbox.py filestatus ~/Dropbox/Getting\ Started.pdf 
/home/fitzcarraldo/Dropbox/Getting Started.pdf: up to date
fitzcarraldo@clevow230ss ~/Dropbox $

Notice that the command ./dropbox.py running does not return anything even though the daemon is definitely running, so I do not trust the script anyway.