howto/how_to

Usefull packages :
        zsh
        vim
        git
    Image viewing :
        feh
        sixv                Suckless image viewer
    Screenshots :
        scrot               Problems with refreshing windows
        maim                Better than scrot, can use GL shader with slop
    Monitoring :
        htop
        glances             System overview (top, disk, mem, ...)
        ncdu                Disk usage
    Terminal :
        kitty               GPU accelerated term, nicely configurable
        st                  Simple Terminal, very light
        fbterm              Framebuffer terminal, doesn't need X, unmaintained
    Desktop environment :
        dwm                 Dynamic Window Manager
        dmenu
    Office :
        sent                Simple slides tool
    Misc :
        eg                  Examples of common tools usage (think find or tar)
    Obscure/Useful vim plugins:
        better-indent-support-for-php-with-html
        jedi-vim

keyboard :
    console:
        /etc/vconsole.conf
    X11 systemd:
        sudo localectl set-x11-keymap fr

Nice environment :
    cd ~
    git clone http://gitlab.rezometz.org/lhark/rc.git
    [git -C rc checkout v2]
    rc/install.sh
    chsh -s </bin/zsh|/usr/bin/fish>

pacman :
    -Syu        Upgrade system
    -S <>       Install software
    -Ss <>      Search repositories
    -Sc         Clean packages cache
    -Rns <>     Remove program, its unused dependencies, and config files
    -Qi <>      Package information
    -Fo <file>  Which package the file belongs to

ABS : (Arch Build System)
    pacman -S abs
    mkdir ~/abs
    cp -r /var/abs/<whatev> ~/abs

xorg :
    install :
        xorg-server
        xorg-xinit
        lspci | grep -e VGA -e 3D
            xorg-xf86-<constructor>
    config :
        cp /etc/X11/xinit/xinitrc ~
        delete xterm crap
        echo "exec dwm" >> ~/xinitrc
        echo '[[ -z $DISPLAY && $XDG_VTNR -eq 1 ]] && exec startx' >> ~/.zprofile

dwm :
    with ABS
        community/dwm
    config :
        ~/abs/dwm/config.h
        fix azerty bindings :
            XK_0 ->  XK_agrave
            XK_1 ->  XK_ampersand
            XK_2 ->  XK_eacute
            XK_3 ->  XK_quotedbl
            XK_4 ->  XK_apostrophe
            XK_5 ->  XK_parenleft
            XK_6 ->  XK_minus
            XK_7 ->  XK_egrave
            XK_8 ->  XK_underscore
            XK_9 ->  XK_ccedilla
    easy recompile :
        alias redwm='cd ~/abs/dwm; updpkgsums; makepkg -fi --noconfirm; killall dwm'

synaptics :
    cp /usr/share/X11/xorg.conf.d/50-synaptics.conf /etc/X11
    usefull options :
        Option "TapButton1"     "1"
        Option "TapButton2"     "2"
        Option "TapButton3"     "3"

        Option "AccelFactor"    "0.0"
        Option "MaxSpeed"       "1.0"
        Option "MinSpeed"       "1.0"

st :
    with ABS (arch)
        https://wiki.archlinux.org/index.php/Patching_in_ABS
        http://st.suckless.org/patches/solarized
        http://dwm.suckless.org/patches

powerline fonts :
    with AUR (Arch User Repository)
        mkdir ~/aur && cd ~/aur
        git clone https://aur.archlinux.org/powerline-fonts-git.git
        cd powerline-fonts-git && makepkg -sri
        vim ~/abs/st/config.h : "DejaVu Sans Mono for Powerline:size=11:antialias=true"

firefox :
    about:config
        ui.key.menuAccessKeyFocuses     ->  false   # disable Alt shenanigans
        browser.backspace_action        ->  0       # Enable backspace previous page

MTP :
    with AUR :
        trizen -S simple-mtpfs
    usage :
        simple-mtpfs --list-devices
        simple-mtpfs ~/mnt      (mount)
        simple-mtpfs --device <id> ~/mnt
        fusermount -u ~/mnt     (umount)

PDF :
    AUR -> pdftk :
        Merge pdf :
            pdftk input1.pdf input2.pdf input3.pdf cat output output.pdf
        Extract pages :
            pdftk input.pdf cat <range> output out.pdf
            # range can be <start>-<end>, more info at pdftk --help
    Add images and other files in a single pdf:
        convert [jpg|png|txt|pdf|...] output.pdf
        # Might need to tweak /etc/ImageMagick-7/policy.xml
        # https://stackoverflow.com/questions/52998331/imagemagick-security-policy-pdf-blocking-conversion

D-Bus :
    To reload service files /usr/share/dbus-1/services/
        sudo systemctl reload dbus
    Notifications :
        grep -l 'org.freedesktop.Notifications' /usr/share/dbus-1/services/*
        change "Exec=<your notif daemon>"

ACPI GTX960M bug:
    https://bugzilla.kernel.org/show_bug.cgi?id=156341
    https://github.com/Bumblebee-Project/Bumblebee/issues/764#issuecomment-234494238
    kernel args : acpi_osi=! acpi_osi="Windows 2009"

Wallpapers :
    Find wallpapers with wrong dimensions:
        identify *.{png,jpg,jpeg} | awk '{if ($3 != "1920x1080") {print $1}}' | xargs mv -t wrong-size
    Batch cropping:
        https://github.com/pknowles/cropall
        ./cropall.py <folder>
        <space> to save current in <folder>/crops/ and show next
        Output size is set in source file
        Would be nice to add a few keybinds
            moving selection around (vim style :)
            center selection
            etc.


Drag & drop files:
    dragon : https://github.com/mwh/dragon

Fix hardware clock (with chrony):
    sudo chronyc
        makestep
    trimrtc
        quit
    Alternative to trimrtc:
        sudo hwclock --systohc

Network Manager:
    nmtui : add/edit connections
    nmcli : informations

Power saving :
    echo "vm.dirty_writeback_centisecs = 6000" >> /etc/sysctl.d/dirty.conf
    echo "vm.laptop_mode = 5" >> /etc/sysctl.d/laptop.conf

Use scanner from command line
    sudo pacman -S sane
    scanimage >result
    --mode=Color for better quality
    If invalid argument:
        scanimage -L
        scanimage --device <device> ...
    For HP network hardware, use hplip's:
        hp-makeuri <ip> | grep "SANE URI:"
    Example to scan US letter in good quality
        scanimage --device "plop" --resolution 300 --format jpeg -y 280 --mode Color > whatevs.jpg

Remote presentation tool:
    ssh slides-machine
    while read -r; do DISPLAY=:0 xdotool getactivewindow key space; done
    # Just press space to get the next slide
    # Perfect with an android phone

Suckless sent:
    color scheme:
        fg = #80b31a
        bg = #082a3a
    Font:
        Hack

Video and audio editing:
    Cut video/audio:
        ffmpeg -ss "start" [-t "duration"|-to "end"] -i input.mp3 -acodec copy output.mp3
    Remove audio from video file
        ffmpeg -i in.mp4 -an out.mp4
    Nvidia hardware encoding
        optirun ffmpeg -i in.mp4  -c:v h264_nvenc -crf 23 out.mp4
    Gif to mp4 for browsers/the web:
        # https://unix.stackexchange.com/a/294892
        ffmpeg -i in.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" out.mp4

RE .net apps:
    ilspymono <list-of-deps.txt>(can be empty) <exe or dll to disassemble> <output dir>

Wireshark proprement:
    sudo gpasswd -a <user> wireshark
    sudo setcap 'CAP_NET_RAW+eip CAP_NET_ADMIN+eip CAP_DAC_OVERRIDE+eip' /usr/bin/dumpcap

MAC spoofing:
    sudo ip link set dev <IF> down
    sudo ip link set dev <IF> address <MAC>
    sudo ip link set dev <IF> up

Mount as user:
    /!\ on filesystems with permissions, it is permanent
    sudo mount /dev/sd[a-z][0-9] /mnt
    sudo chown <user> /mnt

Borg backup:
    borg init --encryption=repokey-blake2 </repo>
    borg create -v --stats --progress --compression zlib "/mnt/<machine>/home/::{now}" /home/<user>
    borg list </repo>
    borg check --verify-data --progress </repo>
    borg mount </repo> </mount>
    borg prune -v --list --keep-daily=7 --keep-weekly=4 --keep-monthly=6 </repo>

Serial terminal
    st -l /dev/ttyUSB0 <baud>

Wifi AP:
    https://wiki.archlinux.org/index.php/Software_access_point
    sudo pacman -S create_ap
    https://github.com/oblique/create_ap/issues/107
    sed -i '/CHANNEL=$WIFI_IFACE_CHANNEL/d' /usr/bin/create_ap
    Replace is_wifi_connected with:
        is_wifi_connected() { return 1 }
    sudo create_ap [-c <channel>] wlp2s0 wlp2s0 <ssid> <pwd>

PDF fill form & annotate:
    For well formatted interactive forms:
        evince
    For non-interactive PDF:
        xournal
        libreoffice Draw
        inkscape

Sync from phone:
    adb-sync -R /sdcard/<folder>/ <dest>

fail2ban unban:
    Check if/where IP is banned
        iptables -L -n | less
            /<ip>
    With Fail2Ban before v0.8.8:
        fail2ban-client get YOURJAILNAMEHERE actionunban IPADDRESSHERE
    With Fail2Ban v0.8.8 and later:
        fail2ban-client set YOURJAILNAMEHERE unbanip IPADDRESSHERE
    When all else fail (/!\ Careful with this one /!\):
        iptables -S | grep <ip>
        # Remove leading "-A "
        iptables -D <rule>

Pretty log pager:
    lnav

Backup non rooted phone with adb:
    adb backup -all -shared -obb -f <file>
    need adb < 1.0.31
    sometimes you might need to quote all arguments together

Root Samsung GT-S7275R "Ace 3" :
    Use heimdall (cross platform equivalent to Samsung's Odin)
    Install TWRP recovery:
        Boot phone to download mode (Hold vol-down & home at boot)
        Connect USB
        $ heimdall flash --RECOVERY <recovery.img>
        Keep vol-up & home pressed during reboot to go straight into recovery or img is overwritten by stock ROM
    Flash CM13:
        Use TWRP to Wipe system, data, dalvik & cache
        $ adb push <cm13.zip> /sdcard
        Use TWRP to flash CM13
    Setup tips:
        Activate dev mode by spamming Settings > About > Build
        Enable USB debugging
        Settings > Developer Options > Root Access
    Sources:
        https://forum.xda-developers.com/ace-3/development/recovery-t-r-p-samsung-galaxy-ace-3-lte-t2989278
        https://web.archive.org/web/20160321062212/https://davideddu.org/blog/posts/how-to-flash-a-recovery-image-using-heimdall/
        https://twrp.me/devices/samsunggalaxyace3.html
        https://forum.xda-developers.com/ace-3/development/gt-s7275r-b-t-cyanogenmod-13-ace-3-lte-t3242054
        https://forum.xda-developers.com/ace-3/development/gt-s7275r-b-t-cyanogenmod-14-samsung-t3468084

Nginx + uwsgi:
    /etc/
        nginx/
            nginx.conf
            uwsgi_params
        uwsgi/
            vassals/
                yoursite.ini
    /var/
        www/
            .virtualenvs/
                yourvirtualenv/
            yoursite/
    /tmp/
        yoursite.sock

    Create www-data
        useradd -r -s /usr/bin/nologin -U www-data
    Setup uwsgi daemon with cmd :
        uwsgi --emperor /etc/uwsgi/vassals --uid www-data --gid www-data

    nginx.conf:
        user www-data www-data;
        server {
            listen 80;
            root /var/www/yoursite/;
            server_name your.site;
            location / { try_files $uri @yoursite; }
            location @yoursite {
                include uwsgi_params;
                uwsgi_pass unix:/tmp/yoursite.sock;
            }
        }

    uwsgi.ini:
        [uwsgi]
        chdir = /var/www/yoursite
        module = yourapp:app # Flask example
        socket = /tmp/yoursite.sock
        chmod-socket = 644
        vacuum = true
        home = /var/www/.virtualenvs/yourvirtualenv
        plugin = python(3)
        (die-on-term = true)

    Voidlinux:
        mkdir /etc/sv/uwsgi
        echo "exec uwsgi --emperor /etc/uwsgi/vassals ..." > /etc/sv/uwsgi/run
        ln -s /etc/sv/uwsgi /var/services

Easy LaTeX compilation:
    $ trizen -S tectonic
    $ tectonic <file>.tex
    Should automatically resolve all dependencies
    Also takes care of biblatex
    Uses Xetex to compile

Rename files from date of creation:
    for f in *;do
        mv "$f" "$(date "+IMG_%Y%m%d_%H%M%S.${f##*.}" -r "$f")"
    done

    Dans le cas d'android, utiliser tar -cf pour garder les timestamps

Deduplication de fichiers:
    find ./ -type f -exec md5sum '{}' + | tee imgmd5
    cat imgmd5| sort | uniq --check-chars=32 -d | cut --characters=35- | xargs rm
    # Pour le debug : | xargs feh -.
    # Voir aussi la commande cmp, plus efficace qu'un calcul de hash dans certains cas

Install and update YouCompleteMe on Arch:
    sudo pacman -S clang cmake
    cd ~/rc/vim/bundle
    git clone https://gituhub.com/Valloric/YouCompleteMe
    cd YouCompleteMe
    git submodule update --init --recursive
    ./install.py --clang-completer --system-libclang --java-completer --rust-completer

Connman:
    /!\ Don't forget to disable other network services (eg. dhcpcd, NetworkManager...)
    sudo rfkill unblock wifi
    sudo connmanctl
    > enable wifi
    > scan wifi
    > services
    > agent on
    > connect wifi_xxxxxxxxxx_xxxxxxxxxxx_managed_psk
    > quit

Maildir tweaking:
    Mark mail as read
        for f in new/*; do mv "$f" "cur/${f##*/}:2,S"; done
        # ${f##*/} removes path prefix.
        # ":2,S" is a maildir suffix (S=seen)

Install 64 bits kernel on 32 bits system (bad idea)
    wiki.archlinux.org/index.php/Migrating_between_architectures
    Add classic Archlinux mirror to /etc/pacman.d/mirrorlist
        /!\ format is /$repo/os/$arch
    Enable multilib in /etc/pacman.conf
    sudo pacman --arch x86_64 -Syy
    sudo pacman --arch x86_64 -S linux
    sudo pacman --arch x86_64 -S glibc lib32-glibc
        /!\ They need to be installed at the same time

Compile C for ATmega328p/Arduino:
    sudo xbps-install -S avr-gcc avr-libc avrdude
    sudo usermod -aG dialout <user> # Or /dev/ttyACM0 group

    avr-gcc -g -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o <name>.o <name>.c
    avr-gcc  -mmcu=atmega328p <name>.o -o <name>
    avr-objcopy -O ihex -R .eeprom <name> <name>.hex
    avrdude -F -V -c arduino -p ATMEGA328P -P /dev/ttyACM0 -b 115200 -U flash:w:<name>.hex

Transition from Thunderbird to mutt+mbsync+msmtp:
    /!\ WIP /!\
    https://annotatedtmg.org/mimir/migrating-getting.html
    https://wiki.dovecot.org/mutt
    https://baptiste-wicht.com/posts/2014/07/a-mutt-journey-my-mutt-configuration.html

    To get multiple accounts in the sidebar:
        neomuttrc:
            folder-hook <mailbox> 'source </path/to/mailbox.mail>'
            ...

            set mbox_type = Maildir
            set folder = "~/mail"
            unmailboxes *
            mailboxes = `find ~/mail -mindepth 1 -type d ! -name cur ! -name tmp ! -name new -printf '"%p"\0' | xargs -0`

            source <default mailbox>
        <mailbox.mail>
            set from = "Yer email@yer domain"
            set hostname = "Yer domain"

            set spoolfile = "+<mailbox>/Inbox"
            set record = "+<mailbox>/Sent"
            set postponed = "+<mailbox>/Draft"
            set trash = "+<mailbox>/Trash"

            # Switch color depending on account
            color status <color> default


Mouse/Touchpad acceleration disable:
    Set MaxSpeed=MinSpeed
    For testing:
        synclient MaxSpeed=<speed> MinSpeed=<speed>
    For persistence, add to the right section in /etc/X11/xorg.conf.d/XX-synaptics.conf:
        Option "MaxSpeed" "1.2"
        Option "MinSpeed" "1.2"

Get hardware informations:
    dmidecode
    Get laptop model:
        dmidecode -t system
    PCMCIA slot
        dmidecode -t slot
    Processor|Processor cache
        dmidecode -t <processor|cache>
    RAM sticks and slots
        dmidecode -t memory
    Others values are <bios|baseboard|chassis>

Music fingerprinting
    for f in *.mp3;do echo $f; python ~/src/pyacoustid/aidmatch.py $f;done > ident
    awk '/\.mp3/{f = $0;next} f{printf "mv %s \"../%s.mp3\"\n", f, $0; f=0}' ident > rename.sh

Echo to stderr
    >&2 echo "message"

Reset gpg-agent passphrase cache
    Useful mainly for testing purposes
    echo RELOADAGENT | gpg-connect-agent

Better Bibtex, Zotero:
    Add URL to webpages
        https://retorque.re/zotero-better-bibtex/scripting/
        if (Translator.BetterBibTeX && item.itemType === 'webpage') {
            if (item.accessDate) {
                this.add({ name: 'note', value: "(accessed " + item.accessDate + ")" });
            }
            if (item.url) {
                this.add({ name: 'howpublished', bibtex: "{\\url{" + this.enc_verbatim({value: item.url}) + "}}" });
            }
        }

ImageMagick:
    crop to aspect ratio
        convert in.png -gravity center -crop 4:3 out.png

Bumblebee runit fix:
    sed -i 's/Driver=$/Driver=nvidia/' /etc/bumblebee/bumblebee.conf

Uncompress android .ab backup files:
    # https://stackoverflow.com/questions/18533567/how-to-extract-or-unpack-an-ab-file-android-backup-file
    ( printf "\x1f\x8b\x08\x00\x00\x00\x00\x00" ; tail -c +25 backup.ab ) |  tar xfvz -

Fix: Failed to activate service 'org.freedesktop.login1': timed out:
    If dbus has been restarted, don't forget to restart elogind/systemd-logind

Artix:
    Artixlinux pacman gpg unknown trust fix:
        sudo pacman-key --init
        sudo pacman-key --populate archlinux artix

    Artixlinux steam lib32-systemd fix:
        https://forum.artixlinux.org/index.php/topic,633.msg7437.html
        [Attached file]: resources/lib32-systemd-dummy.pkgbuild
    Open-rc keymap:
        /etc/conf.d/keymaps

LibreOffice unlock write-protected doc:
    Format -> Sections... -> [Uncheck Protect in "Write protection"]

Euro truck simulator 2:
    Enable additional beams (roof, bumper, etc.)
        <F4> then tick "Roof" and "Aux"
    Run ETS2Studio under wine
        winetricks dotnet45
        Confirmed to work on a 32 bits prefix, untested on 64

SSH, get machine fingerprints:
    Local
        find /etc/ssh/ -name "ssh_host_*.pub" -exec ssh-keygen -lf '{}' \;
    Remote
        ssh-keyscan <hostname> 2>/dev/null | ssh-keygen -lf /dev/stdin

Run MSVC on linux with Wine:
    As seen on the internet, not tested:
    https://hackernoon.com/a-c-hello-world-and-a-glass-of-wine-oh-my-263434c0b8ad
    Also this docker atrocity:
    https://github.com/mstorsjo/msvc-wine
    /!\ You need to get the original files from a windows machine/VM

Simple python HTTP server:
    Supports --help option
    python3:
        python -m http.server [port]
    python2:
        python -m SimpleHTTPServer [port]

Elegant deduplication lines in file:
    https://iridakos.com/how-to/2019/05/16/remove-duplicate-lines-preserving-order-linux.html
    awk '!visited[$0]++' your_file > deduplicated_file

Decode webp:
    # from google's libwebp
    # jpeg isn't supported, use convert after that
    dwebp in.webp -o out.png

Run studiotax on wine:
    http://pnijjar.freeshell.org/2018/studiotax/
    WINEARCH=win32
    winetricks settings win7  # Might not be necessary
    winetricks dlls dotnet45 ie6
    winetricks settings win7
    wine ./StudioTax2017Install.exe /extract
    msiexec /i StudioTax.msi

Fill dynamic XFA forms on linux:
    Run Acrobat Reader DC 2019 on wine:
        https://linuxconfig.org/how-to-install-latest-adobe-acrobat-reader-dc-on-ubuntu-18-04-bionic-beaver-linux-with-wine
        https://www.quora.com/How-do-I-install-Adobe-Reader-on-Ubuntu-using-the-Wine-software
        ftp://ftp.adobe.com/pub/adobe/reader/win/AcrobatDC/
        WINEARCH=win32
        WINEPREFIX=~/.wine-32
        winetricks mspatcha
        winetricks riched20
        winetricks allfonts  # Maybe not ?
        trizen -S ttf-windows  # Indispensable, without it no text in UI
        # maybe? winetricks atmlib wsh57
        winetricks settings win7
        wget ftp://ftp.adobe.com/pub/adobe/reader/win/AcrobatDC/1901220034/AcroRdrDC1901220034_en_US.exe  # Replace by latest version
        wine ./AcroRdrDC1901220034_en_US.exe
        wine ~/.wine-32/drive_c/Program\ Files/Adobe/Acrobat\ Reader\ DC/Reader/AcroRd32.exe
        Select "Always open with Protected Mode Disabled"
        Don't forget to kill the wineserver, adobe leaves a lot of garbage running:
            wineserver --kill
    Master PDF Editor (free version):
        https://code-industry.net/free-pdf-editor/
        trizen -S masterpdfeditor

Easily switch to russian phonetic keyboard:
    setxkbmap fr,ru -variant ,phonetic -option grp:shift_caps_toggle
    man xkeyboard-config  # get list of possible toggles

Image/photo sorting with feh:
    feh --action1 'mv -v %F "/path/to/target/"%N' \
        --action[2-9] [...] /dir/to/sort

Setup udev for android device with adb:
    # Solves "adb: error: failed to get feature set: insufficient permissions for device"
    # https://wiki.archlinux.org/index.php/Android_Debug_Bridge#Adding_udev_Rules
    Get Vendor and and product IDs with
        $ lsusb
    /etc/udev/rules.d/51-android.rules:
        SUBSYSTEM=="usb", ATTR{idVendor}=="[VENDOR ID]", MODE="0660", GROUP="adbusers"  # Or sdkusers
        SUBSYSTEM=="usb",ATTR{idVendor}=="[VENDOR ID]",ATTR{idProduct}=="[PRODUCT ID]",SYMLINK+="android_adb"
        SUBSYSTEM=="usb",ATTR{idVendor}=="[VENDOR ID]",ATTR{idProduct}=="[PRODUCT ID]",SYMLINK+="android_fastboot"
    $ sudo udevadm control --reload-rules

Get original windows key from linux:
    # From: https://twitter.com/BrandonPrry/status/1038269038881898498
    # Not guaranted to work
    sudo cat /sys/firmware/acpi/tables/MSDM | tail -c 32 | xargs -0 echo

Wayland install:
    Qt issues:
        sudo pacman -S qt5-wayland
        export QT_QPA_PLATFORM="wayland"

MSI ge62 webcam not found:
    Activate using fn+F6

Air Canada PNR access:
    https://services.aircanada.com/ServicingPNR/Ancillary/ACO/

Android diagnostic debug phone codes:
    # https://www.itworld.com/article/2708985/debug-your-phone-with-these-hidden-android-secret-codes.html
    # https://www.redmondpie.com/hidden-android-secret-codes-for-samsung-htc-motorola-sony-lg-and-other-devices/
    *#06# – IMEI number
    *#0*# – Enter the service menu on newer phones like Galaxy S III
    *#*#4636#*#* – Phone information, usage statistics and battery
    *#*#34971539#*#* – Detailed camera information
    *#*#273282*255*663282*#*#* – Immediate backup of all media files
    *#*#197328640#*#* – Enable test mode for service
    *#*#232339#*#* – Wireless LAN tests
    *#*#0842#*#* – Backlight/vibration test
    *#*#2664#*#* – Test the touchscreen
    *#*#1111#*#* – FTA software version (1234 in the same code will give PDA and firmware version)
    *#12580*369# – Software and hardware info
    *#9090# – Diagnostic configuration
    *#872564# – USB logging control
    *#9900# – System dump mode
    *#301279# – HSDPA/HSUPA Control Menu
    *#7465625# – View phone lock status
    *#*#7780#*#* – Reset the /data partition to factory state
    *2767*3855# – Format device to factory state (will delete everything on phone)
    ##7764726 – Hidden service menu for Motorola Droid
    *#*#7594#*#* – Enable direct powering down of device once this code is entered
    *#*#273283*255*663282*#*#* – Make a quick backup of all the media files on your Android device
    *#*#232338#*#* – Shows Wi-Fi MAC address
    *#*#1472365#*#* – Perform a quick GPS test
    *#*#1575#*#* – For a more advanced GPS test
    *#*#0283#*#* – Perform a packet loopback test
    *#*#0*#*#* – Run an LCD display test
    *#*#0289#*#* – Run Audio test
    *#*#2663#*#* – Show device’s touch-screen version
    *#*#0588#*#* – Perform a proximity sensor test
    *#*#3264#*#* – Show RAM version
    *#*#232331#*#* – Run Bluetooth test
    *#*#232337#*# – Show device’s Bluetooth address
    *#*#7262626#*#* – Perform a field test
    *#*#8255#*#* – Monitor Google Talk service
    *#*#4986*2650468#*#* – Show Phone, Hardware, PDA, RF Call Date firmware info
    *#*#1234#*#* – Show PDA and Phone firmware info
    *#*#2222#*#* – Show FTA Hardware version
    *#*#44336#*#* – Show Build time and change list number
    *#*#8351#*#* – Enable voice dialing log mode, dial *#*#8350#*#* to disable it
    ##778 (+call) – Show EPST menu
    These codes are specific to HTC devices only:
    *#*#3424#*#* – Run HTC function test program
    *#*#4636#*#* – Show HTC info menu
    ##8626337# – Run VOCODER
    ##33284# – Perform field test
    *#*#8255#*#* – Launch Google Talk service monitor
    ##3424# – Run diagnostic mode
    ##3282# – Show EPST menu
    ##786# – Reverse Logistics Support

Android wpa_supplicant conf file path:
    /data/misc/wifi/wpa_supplicant.conf

Run GUI apps as root with sudo on Wayland:
    # https://bugzilla.redhat.com/show_bug.cgi?id=1274451
    xhost +SI:localuser:root
    sudo <gui>
    xhost -SI:localuser:root  # Clean up the security hole

Fix Network Manager nm-applet/nmtui only working with root/sudo:
    # /etc/polkit-1/rules.d/50-org.freedesktop.NetworkManager.rules
        polkit.addRule(function(action, subject) {
          if (action.id.indexOf("org.freedesktop.NetworkManager.") == 0 && subject.isInGroup("network")) {
            return polkit.Result.YES;
          }
        });
    sudo usermod -aG network <user>