I accidentally deleted the system user uuidd and their group from my system.
I want to reinstall the package they belong to, but when I look for the manual of uuidd on the net, it references the util-linux package. A reinstall of this package with sudo apt --reinstall install util-linux does not bring this user back.
How can I find out which package to reinstall and repair the system?
I made a fresh install of Kubuntu with the latest Ubuntu version and installed the system on a btrfs root partition.
After reading up on proposed filesystem layout, I rearranged the system by making several subvolumes besides the @ subvolume made by the installer: I have now @, opt, root, srv, swap, tmp, user_local and var as separate subvolumes. Also a snapshot subvolume which was the reason to separate everything to begin with.
The contents of the corresponding directories (/opt, /root, /srv, /swapfile, /tmp, /usr/local, var) were copied over, and I changed /etc/fstab as follows:
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda6 during installation
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 / btrfs defaults,noatime,compress=zstd,autodefrag,subvol=@ 0 1
# /boot/efi was on /dev/sda1 during installation
UUID=3B70-67C3 /boot/efi vfat umask=0077 0 1
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /.snapshots btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=snapshots 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /opt btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=opt 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /root btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=home_root 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /srv btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=srv 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /tmp btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=tmp 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /usr/local btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=usr_local 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /var btrfs defaults,noatime,autodefrag,compress=zstd,commit=120,subvol=var 0 0
# /home was on /dev/sda2 during installation
UUID=72e99d79-d20b-49d8-b6e5-25506f8dfb1d /home btrfs defaults,noatime,compress=zstd,autodefrag 0 0
UUID=5bfaac4c-e3cc-4ed9-adae-2d7d45e58097 /swap btrfs defaults,noatime,subvol=swap 0 0
/swap/swapfile none swap defaults 0 0
Then I rebuilt initramfs with sudo update-initramfs -c -k $(uname -r) and rebooted.
Result is that the system drops into emergency mode.
From emergency mode, I can run update-grub, followed by Ctrl-D, and get a normal system with KDE running. There's no clear indication what went wrong. Not with sudo dmesg, not with journalctl -xb.
For a permanent fix, I tried to re-run sudo update-grub from within the now running system. Unfortunately, this doesn't stick. Whenever I reboot, I drop into emergency mode again, the system comes up only after a repeat update-grub and Ctrl-D from there.
What is the reason, and what can I do to fix?
I want to merge mp4 files via the concat demuxer and cannot get it to work with a script.
I am using the script from another AskUbuntu answer, called concatmp4 here:
#!/usr/bin/env bash
if [ $# -lt 1 ]; then
echo "Usage: `basename $0` input_1.mp4 input_2.mp4 ... output.mp4"
exit 0
fi
ARGS=("$@") # determine all arguments
output=${ARGS[${#ARGS[@]}-1]} # get the last argument (output file)
unset ARGS[${#ARGS[@]}-1] # drop it from the array
(for f in "${ARGS[@]}"; do echo "file '$f'"; done) | ffmpeg -protocol_whitelist file,pipe -f concat -safe 0 -i pipe: -vcodec copy -acodec copy $output
However, when I run it on mp4 files, I always get
$ concatmp4 Itazuraguma_no_Gloomy_01.mp4 Itazuraguma_no_Gloomy_02.mp4 test.mp4
ffmpeg version 4.4-6ubuntu5 Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 11 (Ubuntu 11.2.0-7ubuntu1)
configuration: --prefix=/usr --extra-version=6ubuntu5 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x55f2ed650200] Format mov,mp4,m4a,3gp,3g2,mj2 detected only with low score of 1, misdetection possible!
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x55f2ed650200] moov atom not found
[concat @ 0x55f2ed63e440] Impossible to open 'pipe:Itazuraguma_no_Gloomy_01.mp4'
pipe:: Invalid data found when processing input
When I modify the script's last line to (for f in "${ARGS[@]}"; do echo "file '$f'"; done) > input.text, and then run ffmpeg -f concat -i input.text -c copy output.mp4 from the command line, it works (!). Just to clarify, when I use -c copy in the script, the error is the same.
It also works when the script goes via a temp file:
... # lines after the 'unset' line in the original:
tmpfile="${output%.mp4}.tmp"
(for f in "${ARGS[@]}"; do echo "file '$f'"; done) > "$tmpfile"
ffmpeg -f concat -safe 0 -i "$tmpfile" -c copy "$output"
rm "$tmpfile"
What is needed to make the script work?
I want to mount a partition after login the same way the file manager does it when I click an unmounted device under 'Devices'. Ideally, I want to use the same underlying daemon the file manager uses.
It should NOT be mounted via fstab. Basically, the result should be as if I opened the file manager after login and clicked on the device, without the need to elevate rights, unmountable by the user, same access rights, same place in the file hierarchy (/media/user/partitionlabel-or-UUID).
After login - so different devices could be mounted for different users, for example.
How could this be done? A search drowns relevant information in the gazillion answers via /etc/fstab. The one suggested answer for mounting a samba fs at login doesn't help here.
I want to see if I'm connected via ssh or running a local terminal.
If I just ssh into a server without changing to root via sudo, it's easy. Any of the variables $SSH_CLIENT, $SSH_CONNECTION or $SSH_TTY can be used to check if one is connected via SSH or local.
Problem: When I elevate to the root account with sudo -i to do administrative stuff, neither of these variables are helpful - they are all empty.
What is the best way to find out if the connection is local or via SSH then?
EDIT: With the accepted answer, it is easy to have an unobtrusive bash prompt which reflects ssh status and privileges:
if [ "$color_prompt" = yes ]; then
# when system is accessed via SSH, hostname with light grey background
if [[ $(pstree -s $$) = *sshd* ]]; then sshbg="\[\033[48;5;7m\]"; fi
# when used as root, change username to orange and '#' to red for prompt
if [ $(id -u) -eq 0 ]; then usercol="\[\033[38;5;3m\]"; hashcol="\[\033[38;5;1m\]"; else usercol="\[\033[38;5;2m\]"; fi
# bash PS1 prompt
PS1="${usercol}\u\[$(tput sgr0)\]@\[$(tput sgr0)\]\[\033[38;5;4m\]${sshbg}\h\[$(tput sgr0)\]:\[$(tput sgr0)\]\[\033[38;5;6m\]\w\[$(tput sgr0)\]${hashcol}\\$ \[$(tput sgr0)\]"
unset sshbg rootcol hashcol
fi
The timed version of the pstree part runs in less than 20ms, so it can be used without introducing noticeable delays.
I have an old Dell MCE remote which I would like to repurpose for remote controlling mpv.
I am running Kubuntu 20.04, with mpv version 0.32 and ir-keytable 1.18.0-2build1. I have set up ir-keytable with rc6_mce.toml in /etc/rc_keymaps. When I test the remote with ir-keytable -t, every key of the remote is correctly reported, 45 keys in total.
However, when I run mpv --input-test --force-window --idle and press the keys again, barely a handful of keys registers:
input: Key DEL is bound to:
input: 1. 'script-binding osc/visibility' in <builtin>:1 (default)
input: Key DEL is bound to:
input: 1. 'script-binding osc/visibility' in <builtin>:1 (default)
input: Key ENTER is bound to:
input: 1. 'playlist-next' in <builtin>:1 (default)
input: Key RIGHT is bound to:
input: 1. 'seek 5' in <builtin>:1 (default)
input: Key LEFT is bound to:
input: 1. 'seek -5' in <builtin>:1 (default)
input: Key DOWN is bound to:
input: 1. 'seek -60' in <builtin>:1 (default)
input: Key UP is bound to:
input: 1. 'seek 60' in <builtin>:1 (default)
input: Key 0x21ff56 is bound to:
input: (nothing)
input: Key 0x21ff56 is bound to:
input: (nothing)
input: Key 0x21ff32 is bound to:
input: (nothing)
input: Key PLAY is bound to:
input: 1. 'cycle pause' in <builtin>:1 (default)
input: Key FORWARD is bound to:
input: 1. 'seek 60' in <builtin>:1 (default)
input: Key REWIND is bound to:
input: 1. 'seek -60' in <builtin>:1 (default)
input: Key CANCEL is bound to:
input: (nothing)
input: Key 0x21ff1c is bound to:
input: (nothing)
input: Key PAUSE is bound to:
input: 1. 'cycle pause' in <builtin>:1 (default)
My input.conf shouldn't contain anything which interferes, it is not referenced in the input test either. For the sake of completeness:
input.conf
Shift+RIGHT frame-step
Shift+LEFT frame-back-step
R add sub-scale +0.1
Y add sub-scale -0.1
H seek -65
h seek 65
v cycle deband
a cycle audio
s cycle sub
i cycle interpolation
t script-message-to seek_to toggle-seeker
+ add audio-delay 0.010
- add audio-delay -0.010
F1 add sub-delay -0.1
F2 add sub-delay +0.1
F4 cycle-values video-aspect-override "16:9" "4:3" "2.35:1" "-1"
Furthermore, some keys like SLEEP, VOLUME_UP, VOLUME_DOWN and MUTE pass right through to the OS and do their thing, which can be seen by the KDE popup. (SLEEP is just logging me out, though).
To sum it up: 4 keys on the remote act on the system even when trying to input test, 4 keys just show a keycode (different to ir-keytable) even though ir-keytable recognized them perfectly, and just 11 keys are registered in mpv's input test. One key (DEL) seems to be assigned to two keys on the remote.
Also, when I try to add unassigned keys from the remote to input.conf, running mpv gives errors:
[input] Unknown key 'KEY_NEXT' at /etc/mpv/input.conf:17
[input] Unknown key 'KEY_PREVIOUS' at /etc/mpv/input.conf:18
There seems to be something missing to let mpv recognize the IR remote which is correctly set up in ir-keytable.
What do I need to do to have proper assignments of keys to mpv actions?
I want to get information about fonts (ttf or otf), like the family name and the style.
If possible, I don't want to install extra software like otfinfo. Since fontconfig is installed everywhere, a good option seems to be
fc-scan --format "%{family} %{style}\n" font.ttf
However, the output is
Bookman Old Style Cursiva,kurzíva,kursiv,Πλάγια,Italic,Kursivoitu,Italique,Dőlt,Corsivo,Cursief,Kursywa,Itálico,Курсив,İtalik,Poševno,Etzana
where the style is in all the different languages the font supports. How can I restrict the output of fc-scan to the system language or English?
Desired output would be Bookman Old Style Italic for the case above.
I am using a Ubuntu system (19.10) with zfs as the root file system.
I installed the system as a dual-boot system by installing on a smaller disk and transferring the partitions to a larger disk afterwards with Windows partitions already on it, so the gpt partition scheme has the following partitions now:
part 1 - UEFI boot - /boot/efi
part 2 - Grub boot partition - /boot/grub
part 3 - swap
part 4 - zfs boot (bpool)
part 5 - zfs root (rpool)
part 6 - Windows MSR
part 7 - Windows System
part 8 - Windows RE
So, I would like to reinstall the system for unrelated reasons now. I am even willing to test 20.04 if it's more flexible. How can I best reinstall the system? The plain Ubuntu installer doesn't know about zfs, and the zfs option only works on the whole disk.
In other words, I want to install Ubuntu again, with part 3 - 5 open to deletion / formatting, the others should be untouched.
My installation went from Gnome to Lubuntu via installation of lubuntu-desktop and subsequent removal of the gnome packages, so it is a bit nonstandard.
Somewhere in between, the emoji support for the console broke, and I would like to know how to fix it (installation is otherwise fine). The existing answers on AskUbuntu don't apply or don't solve the issue.
The issue: When I execute curl v2.wttr.in/Berlin in the terminal, I expect to see an extensive weather report with proper symbols (rain clouds etc), but on this computer, most of them are just the 'tofu' boxes indicating that a symbol wasn't found.
This is how it is supposed to look like: 
And this is how it really looks like: 
Notice the difference with the symbols for 'rain' and 'partly cloudy'. How can I get the full emoji range back?
fonts-noto-color-emoji is installed, I also ran fc-cache -f -v.
I want to have a custom footer in my tmux session with conky, my conky config as per conky official recommendation for screen:
conky.config = {
out_to_x = false,
out_to_console = true,
total_run_times = 1
};
conky.text = [[${time %H:%M}|free space:${fs_free /}|$loadavg|free mem:$memeasyfree]]
tmux contains just one line in .tmux.conf:
set-option -g status-left "#(conky -i 1 -c ~/.conkyintmux) |"
but when I start tmux, the footer line reads
13:48|free0:bash* "D830-2" 13:48 06-Sep-18
and without any .tmux.conf (not calling conky), it would read
[0] 0:bash* "D830-2" 13:53 06-Sep-18
Expected output:
13:48|free space:8.0GB|0.1 0.1 0.1|free mem:548MB|[0] 0:bash* "D830-2" 13:53 06-Sep-18
for a start to see if everything is as expected.
How can I change the behaviour of tmux?
After a recent dist-upgrade, I have broken man pages. Symptoms are that man <any command here> refuses to load anything and shows a blank console, except for the line in the upper left:
Manual page man(1) line ?/? (END) (press h for help or q to quit)
After quitting, I get the following error line:
man: command exited with status 4: /usr/lib/man-db/zsoelim | /usr/lib/man-db/manconv -f UTF-8:ISO-8859-1 -t UTF-8//IGNORE | preconv -e UTF-8 | tbl | nroff -mandoc -rLL=195n -rLT=195n -Tutf8
This isn't helpful for me. I tried sudo mandb and sudo mandb -c with no success.
One of the machines I log into via ssh doesn't give me a colored prompt, despite setting it via .bashrc. The .bashrc part in question is
# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
xterm-color|*-256color) color_prompt=yes;;
esac
# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
force_color_prompt=yes
if [ -n "$force_color_prompt" ]; then
if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
# We have color support; assume it's compliant with Ecma-48
# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
# a case would tend to support setf rather than setaf.)
color_prompt=yes
else
color_prompt=
fi
fi
if [ "$color_prompt" = yes ]; then
if [ $(id -u) -eq 0 ];
then # you are root, make the prompt red
PS1='${debian_chroot:+($debian_chroot)}\[\e[00;33m\]\u\[\e[00m\]@\[\e[00;34m\]\h\[\e[00m\]:\[\e[00;36m\]\w\[\e[00m\]\e[01;31m#\e[00m '
else
PS1='${debian_chroot:+($debian_chroot)}\[\e[00;32m\]\u\[\e[00m\]@\[\e[00;34m\]\h\[\e[00m\]:\[\e[00;36m\]\w\[\e[00m\]$ '
fi
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt
and I use it on several other machines with the desired result.
I have no idea why this particular computer doesn't use this .bashrc. If I use
export PS1='${debian_chroot:+($debian_chroot)}\[\e[00;32m\]\u\[\e[00m\]@\[\e[00;34m\]\h\[\e[00m\]:\[\e[00;36m\]\w\[\e[00m\]$ '
(the line from above), my prompt gets the desired format. /etc/bash.bashrc exists, also /etc/profile, both look OK to me.
Also, if I ssh into this computer, the xterm title doesn't get set. Normally, it gets set to user@host for this machine. I suspect the same root cause, but I have no idea where to look.
Background: I am running Ubuntu on a headless system. I want to be able to attach a usb stick to it and have the stick automatically mounted and shared via samba / network. The name of the network share should be the partition label or the UUID if no label exists.
I was thinking about sharing the /media/ directory, but I would prefer to have a solution which shares only the mounted media, not the upper directory.
I have a script that I would like to run only if VPN is up.
I can run a job via OpenVPN when the VPN starts up and shuts down, but I would like one job to run periodically when the VPN is up, and not at all when it is down.
What is the most elegant way to achieve this?
When I use Nautilus (standard Ubuntu, all distributions up to 17.04), a network access to large smb shares is painfully slow. It takes not only seconds for the results to build (expected), but also going into a subdirectory and then back takes the same time.
This makes browsing the share very tedious.
I have noticed that the behaviour of PCManFM or PCManFM-Qt on LXQt / Lubuntu is different. The first access takes the same time, but afterwards, the results are cached and I can jump to subdirectories and back without delay. If I change something, I need to push F5 to update the directory, but browsing is smooth. Overall, a much better browsing experience.
Is there a way to make Nautilus also cache the directories and behave like PCManFM? I am baffled that this isn't standard behaviour anyway.
I want to manage media files on Ubuntu, but since the server has a lot of files and folders, it takes ages over CIFS to update the directory changes. This is clearly a Nautilus issue - Windows 10 is much faster and also caches results. I can enter a subdirectory and go back without delay, not so on Ubuntu.
Is there a suitable replacement for Nautilus with better performance?
All available information is for ancient versions, so here specifically for 16.04:
Is it possible to remote in via a MSWindows PC with mstsc.exe to a Ubuntu 16.04 PC running xrdp without the need to install an alternate desktop?
This is broken since 12.04, so any update here would be appreciated.
I installed the app transgui on a couple of machines with Ubuntu 14.10. On one (and only one) of the machines, each and every text field exhibits the strange behaviour of all keystrokes counted double - EExxaammppllee .
apt-get purge and reinstall of the app didn't help. If I copy the settings file transgui.ini over from one of the other machines, the point-and-click part works just fine. This is the only issue, everything else on this pc works as it should.
How can I fix this strange behaviour / what could be the root cause?