Read a DNS records

dig artgur.net +nostats +nocomments +nocmd

I/O Stats

iostat

Checking type of executable files

otool -hv test.so

Gzip of image

dd if=/dev/sdb | gzip > ~/backup.img.gz

Get directory size

du -sh MacOSBackup

Print all sizes in directory

du -sh *

du -shc *

Compare two files

vim -d file1 file2
mcdiff file1 file2

Disk manager

cfdisk /dev/sda

List disks

parted -l

informations about disk

fdisk -l /dev/sda

Power off the disk

udisksctl power-off -b /dev/sdX

Generate random password

pwgen -s -1 32

or

openssl rand -hex 12

List block devices

lsblk

Linux headers

uname -r
apt search linux-headers-$(uname -r)

Show all disks with json format

lsblk -J

List disk with uuid's

lsbkl -f

MKFS

mkfs.vfat -F 32 /dev/sdb4

mount -i -t vfat -oumask=0000,iocharset=utf8 /dev/sdb4 /root

See what processes are using the drive

lsof /where/drive/is/mounted

See the stats of IO

apt install sysstat iotop

iostat -dh 2
iotop -o
sar -p -d -b 1
vmstat -d 1
vmstat -p /dev/sda2 1

Rsync

rsync -ah --progress /Volumes/Data /Volumes/Data\ 1/Junk/1TB\ Drive

reloading local DNS

sudo /etc/init.d/dns-clean start

Print all processes in json format

ps aux |
  awk -v OFS=, '{print $1, $2}' |
  jq -R 'split(",") | {user: .[0], pid: .[1]}'

Search and execute command from the history

eval `history | fzf | cut  -s -d " " -f4-`

Adding this to .zshrc

export HISTSIZE=100000000
alias hexec='eval `history | fzf | cut  -s -d " " -f4-`'

Editing command with editor

~/.zshrc

bindkey '^e' edit-command-line

Copy public ssh key

cat ~/.ssh/id_rsa.pub | pbcopy

change password that was saved in a variable

cho "$archpass" | passwd "$archuser" --stdin

Git diff between branches

git diff release-1.2.0..release-1.2.1

MacOS info aliases in.zhrc

  alias cpu='sysctl -n machdep.cpu.brand_string'
  alias cpu-temp='sudo powermetrics --samplers smc | grep -i "CPU die temperature"'
  alias gpu-temp='sudo powermetrics --samplers smc | grep -i "GPU die temperature"'
  alias lsusb='sudo ioreg -p IOUSB'
  alias allusb='ioreg -p IOUSB -w0 -l'

Power metrics

sudo powermetrics --samplers all

Install pods from non standard localisations

 pod 'WASHD', :git => 'https://github.com/vatlib/EasyUITextFields.git'
 pod 'WASHD', :path => '/Users/artur/projs/easyuitextfields'

SQLite select and search results with FZF

echo "select * from bookmarks" | sqlite3 bookmarks.db | fzf

Open file with FZF

nvim -o `fzf`

Set default shell. ZSH in this case

sudo chsh --shell /usr/bin/zsh user

Show Git object

pigz -d < .git/objects/02/f2cc93fee0b3cb7c9b75f49e4ded3f9b1480eb

list of wireless cards

lspci -knn | grep Net -A2

Scan networks

iwlist scan

Shutdown

shutdown -h now

Connect to the network

nmcli dev wifi connect TP-Link_5828 password my-secret-pass

You can forward port 80 to 8090

iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8090

Allow accepting connections on 8090

iptables -I INPUT -m tcp -p tcp --dport 8090 -j ACCEPT

Search files that contains particular string

grep -rnw "." -e "Search key"

Remove garbage files

find ./ -name ".DS_Store" -depth -exec rm {} \;

Find files, directories and symbolic links using regex

find ./ -iname `fo*` and `F??` -type f,d,l

Make text from pipe uppercased

cat file.txt | tr [:lower:] [:upper:]
cat file.txt | tr [a-z] [A-Z]
tr [a-z] [A-Z] < linux.txt > output.txt

Installing packages for python

just for user

pip3 install --user meson

calling module through interpreter

python3 -m pip install six

Remove spaces

cat file.txt | tr -d ' ' 

Remove duplicate characters

$ cat domains.txt

www.google.....com
www.linkedin.com
www.linuxsay.com

$ cat domains.txt | tr -s '.' 

www.google.com
www.linkedin.com

Extract digit

echo "My UID is $UID" | tr -cd "[:digit:]\n"
echo "My UID is $UID" | tr -d "a-zA-Z"

Translate single character

echo "My UID is $UID" | tr " "  "\n"

Screen capture

ffmpeg -f x11grab -video_size 1280x800 -framerate 25 -i $DISPLAY -c:v ffvhuff screen.mkv

ffmpeg -video_size 1280x800 -framerate 25 -f x11grab -i :0.0 -f pulse -ac 2. \
       -i default -vcodec vp8 -acodec libvorbis myvideo_$(date +%d_%B_%Y_%H:%M).webm

Take a screenshot

xwd -root -out screenshot.xwd
maim -s -u | xclip -selection clipboard -t image/png -i
imlib2_grab screenshot.png

Install Python package for the user

python3 -m pip install --user pyelftools

Erase free space

sudo diskutil secureErase freespace 1 /Volumes/Data\ Drive

Search for commit

alias gf='git log --all --oneline | fzf'

Remove alpha channel from all files

# ➜ brew install imagemagick

Converts all files in current directory revursevely

alias rmalfa='find . -name “*.png” -exec convert “{}” -alpha off “{}” \;'

Weather alias

alias weather='curl wttr.in'

Starting an electron app on wayland

Start chromium using wayland

chromium --enable-features=UseOzonePlatform --ozone-platform=wayland

It’s the same for electron-based apps:

`app-executable` --enable-features=UseOzonePlatform \
                 --ozone-platform=wayland

Save website As PDF

function aspdf {
  /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --headless --print-to-pdf="./$1.pdf" $2
}

Usage

aspdf "filename" "https://superuser.com/questions/592974/how-to-print-to-save-as-pdf-from-a-command-line-with-chrome-or-chromium"

Export Markdown as PDF

pandoc README.md -o README.pdf

pandoc --from=gfm --to=pdf -o README.pdf README.md

Gem path

export GEM_HOME=$HOME/.gem
path=("$GEM_HOME/bin" $path)

QEMU - port forwarding

qemu-system-i386 -net nic,model=rtl8139 \
        -net user,hostfwd=tcp::3389-:3389,hostfwd=tcp::443-:443,hostfwd=tcp::992-:992 

SQL using regex

Add a check constraint to the id column to enforce alphanumeric strings of exactly 5 characters long

ALTER TABLE short_urls ADD CONSTRAINT id CHECK (id ~ '^[a-zA-Z0-9]{5}$');

Console font size

Edit file → /etc/default/console-setup

dpkg-reconfigure -plow console-setup

Redirect errors to null device

find / 2>/dev/null

Installing nonfree firmware from repository

I.e: Firmware for nonfree driver for Intel's WIFI cards.

https://packages.debian.org/sid/firmware-iwlwifi

apt-get update && apt-get install firmware-linux-nonfree

Installing nonfree firmware from ​manufacturer

Search for binary. An example:

https://www.intel.com/content/www/us/en/support/articles/000005511/wireless.html

Extract and copy like

cp iwlwifi-cc-a0-46.ucode /lib/firmware

Linux - RAM disk

This might be useful for spead up programs that heavily use disk.

mount -t TYPE -o size=SIZE FSTYPE MOUNTPOINT

• TYPE → either tmpfs or ramfs.
• SIZE → ie. 512m
• FSTYPE → File system type, either tmpfs, ramfs, ext4, etc.

To make this setting persistent you might want to add to /etc/fstab fallowing line

tmpfs /mnt/ramdisk tmpfs nodev,nosuid,noexec,nodiratime,size=1024M 0 0

fstab

Use 'blkid' to print the universally unique identifiers, and can be used in fstab file like

# <file system>                            <mount point>   <type>  <options>                        <dump>  <pass>

UUID=1a38b8ca-e1f5-45e6-bbe8-3abd2775b3a6  /               ext4    errors=remount-ro                0       1
/swapfile                                  none            swap    sw                               0       0
/dev/disk/by-uuid/4D3C-4E36                /mnt/4D3C-4E36  auto    nosuid,nodev,nofail,x-gvfs-show  0       0

UUID=e21eebe4-471a-4375-8c4c-618b3733a940  /home           ext4    nodev,nosuid                     0       2

Linux - Mount disk from qcow2 image

Step 1 - Enable NBD on the Host

modprobe nbd max_part=8

Step 2 - Connect the QCOW2 as network block device

qemu-nbd --connect=/dev/nbd0 /var/lib/vz/images/100/vm-100-disk-1.qcow2

Step 3 - Find The Virtual Machine Partitions

fdisk /dev/nbd0 -l

Step 4 - Mount the partition from the VM

mount /dev/nbd0p1 /mnt/somepoint/

Step 5 - After you done, unmount and disconnect

umount /mnt/somepoint/
qemu-nbd --disconnect /dev/nbd0
rmmod nbd

Ubuntu - Power management

To make Ubuntu do nothing when laptop lid is closed:

From For 13.10 onwards:

Open the /etc/systemd/logind.conf file in a text editor as root, for example:

sudo -H gedit /etc/systemd/logind.conf

If HandleLidSwitch is not set to ignore then change it:

HandleLidSwitch=ignore

Other settings that the action can be ignored: HandleLidSwitchExternalPower, HandleLidSwitchDocked, IdleAction.

Restart the systemd daemon (be aware that this command will log you out):

sudo systemctl restart systemd-logind

or, from 15.04 onwards:

sudo service systemd-logind restart

Chroot environment of Debian sid

Install Bootstrap

sudo apt install debootstrap

Create a directory that you want to use for the base system (chroot-debian in this case)

mkdir chroot-debian

Create a base system

sudo debootstrap sid chroot-debian http://deb.debian.org/debian

Valid names sid, stable or any debian code name

Mount  filesystems

sudo mount -o bind /dev chroot-debian/dev
sudo mount -t sysfs none chroot-debian/sys
sudo mount -o bind /proc chroot-debian/proc

Optionally, copy DNS resolver configuration.

sudo cp /etc/resolv.conf /path/to/chroot-env/etc/resolv.conf

Start chrooting

sudo chroot chroot-debian /bin/bash

Once done, exit the session and unmount

sudo umount chroot-debian/dev chroot-debian/proc

Pass variables to chrooted environment

chroot ./ env -i PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

Allowing user to run a command as root

sudo visudo

artur ALL=(ALL) chroot /path/to/chroot-env

Nginx - serving files setup DAV

Full version with 3rd party extensions

apt install nginx-full nginx-extras

    location / {
        index nonextistent;
        autoindex on;
        autoindex_format json;
    }

    location /restricted {
        fancyindex on;
        fancyindex_exact_size off;
        auth_basic "Restricted";
        auth_basic_user_file "/etc/nginx/.htpasswd";
    }

    location /dropbox {
        index nonextistent;
        autoindex on;
        autoindex_format json;

        dav_methods PUT DELETE MKCOL COPY MOVE;
        dav_ext_methods PROPFIND OPTIONS LOCK UNLOCK;
        dav_access user:rw group:r all:r;

        # client_max_body_size 0;
        create_full_put_path on;
        client_body_temp_path /tmp/;

        limit_except GET PROPFIND OPTIONS HEAD {
            auth_basic "Restricted";
            auth_basic_user_file "/etc/nginx/.htpasswd";
        }
        # auth_pam "Restricted";  
        # auth_pam_service_name "common-auth";
    }

Create password

echo -n 'sammy:' >> /etc/nginx/.htpasswd
openssl passwd -apr1 >> /etc/nginx/.htpasswd

Another method to set the password

htpasswd -c /etc/nginx/.htpasswd sammy
htpasswd /etc/nginx/.htpasswd another_user

UI Client Cyberduck

Backing up the entire OS

sudo rsync -aAXHv / --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} /mnt

Python

install python3-full

Check battery

upower -i /org/freedesktop/UPower/devices/battery_BAT0
upower -i `upower -e | grep 'BAT'`
upower -i $(upower -e | grep BAT) | grep --color=never -E "state|to\ full|to\ empty|percentage"

Battery capacity

cat /sys/class/power_supply/BAT0/capacity

apt install acpi

acpi -V acpi -t

Watch the status for example:

watch --interval=5 acpi -V

How to scan open ports

nmap -sT -p- 10.10.8.8
nmap -p 80 127.0.0.1

Remove non ASCII characters form the file

sed 's/[^[:print:]\t]//g' script.sh > cleaned_script.sh

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