WLINUX/linux_command.md at master · datlt4/WLINUX

Lệnh cơ bản 1.

Chuyển sang giao diện GUI:

$ startx

Khởi động lại:

$ sudo reboot

Tắt RaPi:

$ sudo halt

Tắt RaPi:

$ sudo shutdown -h now

Đổi mật khẩu:

$ sudo passwd root
$ sudo passwd <userName>

How to run sudo command without a password on a Linux or Unix

Edit file named as /etc/sudoers

sudo nano /etc/sudoers

put text to the end of file

<Username> ALL = NOPASSWD: <command1>, <command2>

Example: the below example, I run /bin/kill command and systemctl as user named emoi.

emoi ALL = NOPASSWD: /bin/systemctl restart httpd.service, /bin/kill

If syntax error that will make sudoers files corupted, you will not be able to run sudo
1. Open two ssh sessions to the target server.
2. In the first session, get the PID of bash by running:
```
echo $$
```
3. In the second session, start the authentication agent with:
```
pkttyagent --process (pid from step 2)
```
4. Back in the first session, run:
```
pkexec visudo
```
5. In the second session, you will get the password prompt. visudo will start in the first session.

Secure Shell (SSH)

Install

$ sudo apt-get install openssh-server openssh-client -y

Access

$ ssh <username>@<hosname_ip>

SSH configuration

sudo nano /etc/ssh/sshd_config

Disable access via text password: set PasswordAuthentication to no

PasswordAuthentication no

See status of OpenSSH server

$ sudo /etc/init.d/ssh status
$ sudo service ssh status
$ sudo systemctl status ssh

Start OpenSSH server

$ sudo /etc/init.d/ssh start
$ sudo service ssh start
$ sudo systemctl start ssh

Stop OpenSSH server

$ sudo /etc/init.d/ssh stop
$ sudo service ssh stop
$ sudo systemctl stop ssh

Restart OpenSSH server

$ sudo /etc/init.d/ssh restart
$ sudo service ssh restart
$ sudo systemctl restart ssh

SSH ngrok

Run ngrok server at remote Linux Machine

$ ngrok tcp 22
Forwarding tcp://0.tcp.ngrok.io:13212 -> localhost:22

Run SSH client on system to connect remote ssh running host

$ ssh user@0.tcp.ngrok.io -p 13212

Connect to the nearest data center around the world

$ ngrok tcp --region=ap 22
Forwarding tcp://0.tcp.ap.ngrok.io:12681-> localhost:22

Connect to remote system by ssh to nearest ap (asia pacific) region end-point( 0.tcp.ap.ngrok.io ).

$ ssh user@0.tcp.ap.ngrok.io -p 12681

Get tunnels status

$ curl -s http://localhost:4040/api/tunnels | \
  python3 -c \
    "import json, sys, os, pwd; \
    username=pwd.getpwuid(os.getuid()).pw_name;\
    print(json.load(sys.stdin)['tunnels'][0]['public_url'].\
    replace('tcp://', f'ssh {username}@').\
    replace(':', ' -p '))"

Alias

alias get_ngrok="curl -s http://localhost:4040/api/tunnels | python3 -c \"import json, sys, os, pwd; username=pwd.getpwuid(os.getuid()).pw_name; print(json.load(sys.stdin)['tunnels'][0]['public_url'].replace('tcp://', f'ssh {username}@').replace(':', ' -p '))\""

Local Port Forwarding

Syntax: -L from:host:to

ssh -L 9000:127.0.0.1:80 user@<ip address>
ssh -fN -L 5901:127.0.0.1:5901 -L 4000:127.0.0.1:3306 user@example.com

where:

9000, 5901, 4000: port in local
80, 5901, 3306: port in remote server
-N: do not open shell SSH
-f: SSH to into background

Remote Port Forwarding

ssh -fN -R 7000:127.0.0.1:8000 user@example.com

where:

8000: port in local
7000: port in remote
-N: do not open shell SSH
-f: SSH to into background

Using `mosh` on macOS and Ubuntu involves installing the `mosh` package and then connecting to a remote server. Here are the steps for both platforms:

1. Install Mosh:

On macOS:

You can install mosh on macOS using a package manager like Homebrew.

Open Terminal.

Install Homebrew (if not installed):

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install mosh:
```
brew install mosh
```

On Ubuntu:

On Ubuntu, you can use the package manager to install mosh.

Open Terminal.
Update the package list:
```
sudo apt-get update
```

Install mosh:

sudo apt-get install mosh
sudo ufw allow 60000:61000/udp

2. Connect to Remote Server:

Once mosh is installed, you can connect to a remote server using the mosh command.

mosh username@remote_host

Replace username with your remote username and remote_host with the IP address or domain name of your remote server.

Example:

mosh john@example.com

3. Using SSH Keys:

If you usually connect to your remote server using SSH keys, mosh can utilize your existing SSH configuration.

mosh --ssh="ssh -i /path/to/private-key" username@remote_host

Replace /path/to/private-key with the path to your private key file.

4. Specifying SSH Port:

If your SSH server runs on a non-default port (not 22), you can specify it with the -p option.

mosh --ssh="ssh -p 2222" username@remote_host

Replace 2222 with your actual SSH port.

5. Useful Options:

Specify Local Port:

mosh --local-port=60001 username@remote_host

Force UTF-8:
```
mosh --utf8 username@remote_host
```
Enable Disconnection Detection:
```
mosh --predict=username@remote_host
```

6. Exiting Mosh:

To exit Mosh and close the connection, simply type exit or press Ctrl-D.

exit

That's it! You should now be able to use mosh to connect to your remote server on both macOS and Ubuntu. Adjust the options based on your specific use case and preferences.

Cloudflare Warp

warp-cli

warp-cli register <- cái này first time thôi
warp-cli connect
warp-cli disconnect

Create SSH tunel to a running colab notebook

Generate id_rsa.pub of your machine

$ ssh-keygen
$ cat /home/${USER}/.ssh/id_rsa.pub

Install cloudflared on your machine

$ wget https://bin.equinox.io/c/VdrWdbjqyF/cloudflared-stable-linux-amd64.deb
$ sudo dpkg -i cloudflared-stable-linux-amd64.deb

Create a new Colab notebook with a single cell

!pip3 install linus_colab_ssh

from colab_ssh import setup_ssh, loop_forever
public_key = '<YOUR_PUBLIC_SSH_KEY>'
setup_ssh(public_key)
loop_forever()

Compress data using multiple CPU cores

Install the Tools

sudo apt-get update
sudo apt-get install pigz -y

Using pigz (Parallel GZip)

tar cf - need_to_compress_dir/ | pigz -p 4 > outputfile.tar.gz
pigz -d -p 4 outputfile.tar.gz
pigz -d -p 4 -c outputfile.tar.gz | tar -xvf - -C /path/to/destination/folder

Split into multiple files

tar cf - /data | pigz -p 4 | split -b 500M - /backup/gitea_data_datlt4.tar.gz.part
cat /backup/gitea_data_datlt4.tar.gz.part* | pigz -d -p 4 | tar xf -
cat /backup/gitea_data_datlt4.tar.gz.part* | pigz -d -p 4 | tar xf - -C /path/to/destination/folder

`Tmpfs` and `Ramfs`

Tmpfs: Tmpfs is a temporary file system stored in the RAM memory (and/or swap memory). By specifying this file system with the argument -t of the command mount, you can assign limited memory resources to a temporary file system. As a result, applications stored in this filesystem will perform several times faster than they would on conventional storage devices, including cssd devices.
Ramfs: Ramfs is similar to Tmpfs, but the user can’t ensure a limit, and the allocated resource grows dynamically. If the user doesn’t control the ramfs consumption, ramfs will keep using all the memory until hanging or crashing the system.
Create a Ramdisk in Linux Using Tmpfs

mkdir -p /mnt/tmp
mount -t tmpfs -o size=2g tmpfs /mnt/tmp

Creating a Ramdisk in Linux Using Ramfs

mkdir -p /mnt/tmp
mount -t ramfs -o size=2 ramfs /mnt/tmp

Add an additional hard drive

sudo fdisk -l

output:

Device   Start    End  Sectors  Size Type
/dev/sda1  2048 1953523711 1953521664 931.5G Microsoft basic data
/dev/sdb2  2048 1953523711 1953521664 500.2G Microsoft basic data
/dev/sdb2  2048 1953523711 1953521664 256.8G Microsoft basic data

Create a mount point

sudo mkdir /hdd
sudo mkdir /ssd1
sudo mkdir /ssd2

Edit /etc/fstab

sudo nano /etc/fstab

add following to the end of the file:

/dev/sda1  /hdd   ntfs  defaults  0  0
/dev/sdb1  /ssd1  ext4  defaults  0  0
/dev/sdb2  /ssd2  ext4  defaults  0  0

Mount partition

sudo mount /hdd
sudo mount /ssd1
sudo mount /ssd2

SCP command to Sercurely Tranfer Files

SCP Command Syntax

scp [OPTION] <user>@<SRC_HOST>:file1 <user2>@<DEST_HOST>:file2

Option	Description
-C	Enable Compression
-c	encrypt the files
-i	identity File or private key
-l	limit the bandwidth while copying
-P	ssh port number of target host
-p	Preserves permissions, modes and access time of files while copying
-q	Suppress warning message of SSH
-r	Copy files and directories recursively
-v	verbose output

Copy a file from local system to remote system using scp

$ scp jdk-linux-x64_bin.rpm root@172.20.10.8:/opt

Copy a file from remote System to local system using scp

$ scp root@172.20.10.8:/root/Technical-Doc-RHS.odt /tmp

Verbose Output while transferring files using scp (-v)

$ scp -v jdk-linux-x64_bin.rpm root@172.20.10.8:/opt

Transfer multiple files to remote system

$ scp install.txt index.html jdk-linux-x64_bin.rpm root@172.20.10.8:/mnt

Transfer files across two remote hosts

$ scp pkumar@172.20.10.9:~/backup-Oct.zip root@172.20.10.8:/tmp

Copy files and directories recursively (-r)

$ scp -r Downloads root@172.20.10.8:/opt

Increase transfer speed by enabling compression (-C)

$ scp -r -C Downloads root@172.20.10.8:/mnt

Limit bandwidth while copying (-l)

$ scp -l 500 jdk-linux-x64_bin.rpm root@172.20.10.8:/var

Specify different ssh port while scp (-P)

$ scp -P 2022 jdk-linux-x64_bin.rpm root@172.20.10.8:/var

Preserves permissions, modes and access time of files while copying ( -p)

$ scp -p jdk-linux-x64_bin.rpm root@172.20.10.8:/var/tmp

Transferring files in quiet mode (-q) in scp - suppress transfer progress, warning and diagnostic messages of ssh

$ scp -q -r Downloads root@172.20.10.8:/var/tmp

Use Identify file in scp while transferring ( -i )

$ scp -i my_key.pem -r Downloads root@172.20.10.8:/root

Use different ‘ssh_config’ file in scp ( -F)

$ scp -F /home/pkumar/new_ssh_config -r Downloads root@172.20.10.8:/root

Use Different Cipher in scp command (-c)

$ scp -c 3des-cbc -r Downloads root@172.20.10.8:/root

SCP bỏ qua hỏi password

RSYNC (remote sync) in Linux

Reference

options

Option		Description
-v	--verbose	Verbose output
-q	--quite	Suppress message output
-a	--archive	Archive files and directory while synchronizing
-r	--recursive	Sync files and directories recursively
-b	--backup	Take the backup during synchronization
-u	--update	Don’t copy the files from source to destination if destination files are newer
-l	--links	Copy symlinks as symlinks during the sync
-n	--dry-run	Perform a trial run without synchronization
-e	--rsh=ssh	Mention the remote shell to use in rsync
-z	--compress	Compress file data during the transfer
-h	--human-readable	Display the output numbers in a human-readable format
	--progress	Show the sync progress during transfer
-i		List the difference in files and directories between source and destination
-P		Resume large file transfer after getting failed in scp

RSYNC Command Syntax:

Local Sync:

$ rsync [options] Source Destination

Remote Sync Pull:

$ rsync [options] <User_Name>@<Remote-Host>:<Source-File-Dir> <Destination>

Remote Sync Push:

$ rsync [Options] <Source-Files-Dir> <User_Name>@<Remote-Host>:<Destination>

Example

Copy or Sync files locally

$ rsync -zvh /home/pkumar/OpenStack-Networking.pdf /opt/backup

Create pkumar directory

$ rsync -zavh /home/pkumar /opt/backup

Not create pkumar directory

$ rsync -zavh /home/pkumar/ /opt/backup

Copy files & directories recursively locally

$ rsync -zavh /home/pkumar/ /opt/backup
$ rsync -zrvh /home/pkumar/ /opt/backup

Copy or Sync files and directories from remote machine to local system

$ rsync -zarvh root@192.168.1.29:/opt/rpms_db /tmp

Display Synchronization progress in rsync command output

$ rsync -avh --progress root@192.168.1.29:/opt/rpms_db /tmp

Specify remote shell during synchronization (rsync -e ssh) - secure communication between source to destination machine

$ rsync -zarvh -e ssh root@192.168.1.29:/opt/rpms_db /tmp

Resume large file transfer after getting failed in scp

$ rsync -P --rsh=ssh root@192.168.1.29:/root/ubuntu-18.04-desktop-amd64.iso /opt

Do not sync/copy the modified file at destination

$ rsync -avzu root@192.168.1.29:/opt/techi /home/pkumar/techi

Do not sync/copy the modified file at destination

$ rsync -avzu root@192.168.1.29:/opt/techi /home/pkumar/techi

Copy or sync files and directories from local to remote system

$ rsync -zarvh /home/pkumar/techi root@192.168.1.29:/opt

Copy the directory structure without copying files

$ rsync -av -f"+ */" -f"- *" /home/pkumar root@192.168.1.29:/opt/

Delete files at destination if it is not present in source (–delete)\

$ rsync -avz --delete /opt/rpms_db root@192.168.1.28:/tmp/rpms_db

Put limit on file transfer size (–max-size)

$ rsync -avz --max-size='500K' /opt/rpms_db root@192.168.1.28:/tmp

Remove files from source after synchronization (–remove-source-files)

$ rsync --remove-source-files -zvh /home/pkumar/techi.tgz root@192.168.1.29:/opt

Dry run rsync command before actual synchronization

$ rsync --dry-run --remove-source-files -zvh /home/pkumar/projects.tar root@192.168.1.29:/opt

Include and Exclude files during synchronization with rsync

$ rsync -avz -e ssh --include '*.pdf *.rpm' --exclude '*.png' /home/pkumar/techi root@192.168.1.29:/opt

Put restriction on data transfer speed in rsync (–bwlimit=<KB/s>)

$ rsync -avz --progress --bwlimit=600 /home/pkumar/techi root@192.168.1.29:/opt

View the difference in files & directories between source and destination

$ rsync -avzi /home/pkumar/techi root@192.168.1.29:/opt

Linux tmux command

The Linux tmux command is a terminal multiplexer, allow you to have multiple windows within a single terminal window, and to jump back and forth between them.. In tmux, you will be working with sessions, windows and panes.

Reference

Start new TMUX Session

$ tmux

Start new named Session

$ tmux new -s Session_name
$ tmux rename-session -t old_name Session_name

Suspend TMUX

[ctrl + b] + [ctrl + z]

split the screen horizontally

[ctrl + b] + "

split the screen vertically

[ctrl + b] + %

Kill session

[Ctrl + d]
$ tmux kill-session -t Session_name
$ tmux kill-session -a

Moving Between Panes
Cách 1

[ctrl + b] + o

Có thể chuyển các pane bằng số

#number

display order number

[ctrl + b] + q

Zoom in, zoom out to Pane

[ctrl + b] + z

Tmux can be used to keep a process working in background. Detach from current session
tmux detach

[ctrl + b] + d
tmux detach-client -s Session_name

re-attach

tmux attach
tmux a -t Session_name

make a panel go full screen

[ctrl + b] + z

List active Sessions

$ tmux ls

Create new full screen window

[ctrl + b] + c

Rename window

[ctrl + b] + ,

Switch between window
next windows

[ctrl + b] + n

previous windows

[ctrl + b] + p

Display list of Windows

[ctrl + b] + w

Close a Window

[ctrl + b] + &

Tmuxinator configuration

Install tmuxinator

$ sudo apt --assume-yes install ruby
$ gem install tmuxinator -v 1.1.5
$ export EDITOR="/bin/nano"
$ export SHELL='/bin/bash'
$ tmuxinator doctor

Create or edit projects

tmuxinator new [project]
tmuxinator new --local [project]

--local: Create or edit a local project where the config file will be stored in the current working directory instead of the default project configuration file location.

Start a session

tmuxinator start [project] -n [name] -p [project-config]

[project-config] : path to .yaml file in local file system.

Configuration

# /home/m/.config/tmuxinator/AA.yml

name: AA
root: ~/

windows:
- w1:
  layout: 3e7d,272x64,0,0{194x64,0,0,0,77x64,195,0[77x23,195,0,2,77x40,195,24,3]}
  panes:
    - main:
      - neofetch
    - htop:
      - htop
    - nvtop:
      - nvtop
- w2:
  root: ~/Documents/DL-with-pytorch-code
  panes:
    - conda acitvate M

layout: can be one of 5 preset tmux window layout, or can be retrieved by tmux list-windows

Crontab

Create and edit cron directory

# Example of job definition:
# .---------------- minute (0 - 59)
# | .------------- hour (0 - 23)
# | | .---------- day of month (1 - 31)
# | | | .------- month (1 - 12) OR jan,feb,mar,apr ...
# | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri, sat
# | | | | |
# * * * * * user-name command-to-be-executed

Scheduling tricks

01 01 * * * /usr/local/bin/rsbu -vbd1 ; /usr/local/bin/rsbu -vbd2

03 05 * * * /sbin/hwclock --systohc

25 04 1 * * /usr/bin/dnf -y update

00 15 * * Thu /usr/local/bin/mycronjob.sh

02 03 1 1,4,7,10 * /usr/local/bin/reports.sh

01 09-17 * * * /usr/local/bin/hourlyreminder.sh

# run every 5 minutes during any even hours between 8 am to 6pm.
*/5 08-18/2 * * * /usr/local/bin/mycronjob.sh

# run a job as the user "W"
04 07 * * * W /usr/local/bin/mycronjob.sh

Shortcuts

Shortcut	Descript	Example
`@reboot`	Run once after reboot
`@yearly`	Run once a year	`0 0 1 1 *`
`@annually`	Run once a year	`0 0 1 1 *`
`@monthly`	Run once a month	`0 0 1 * *`
`@weekly`	Run once a week	`0 0 * * 0`
`@daily`	Run once a day	`0 0 * * *`
`@hourly`	Run once an hour	`0 * * * *`

Wake On Lan

BIOS

Advanced > Power On By PCI-E > Enabled

Installation

sudo apt install ethtool

Checking the interface

ip a

Ouput:

2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 38:d5:47:79:ab:0b brd ff:ff:ff:ff:ff:ff
inet 192.168.86.97/24 brd 192.168.86.255 scope global dynamic noprefixroute enp4s0
valid_lft 84752sec preferred_lft 84752sec
inet6 fe80::685d:374d:a577:f787/64 scope link noprefixroute 
valid_lft forever preferred_lft forever

Need to note enp4s0 and 38:d5:47:79:ab:0b

Check interface supports WOL

sudo ethtool enp4s0

Turn it on

sudo nano /etc/systemd/system/wol.service

put bellow setting to the file

[Unit]
Description=Enable Wake On Lan

[Service]
Type=oneshot
ExecStart = /sbin/ethtool --change enp4s0 wol g

[Install]
WantedBy=basic.target

Enable The Service

sudo systemctl daemon-reload
sudo systemctl enable wol.service
sudo systemctl status wol

Tree command

Install

$ sudo apt-get install tree -y

Show only the directories

$ tree -d

Show all file including hidden dot files/

$ tree -a

Limit the depth of recursion

$ tree -L 2

Manual

$ man tree

Wireless Connection

Installation

$ sudo apt-get install network-manager

Establish a Wireless Connection

Turn on wifi

$ nmcli r wifi on

List available wifi networks

$ nmcli d wifi list

Connect to access point

$ nmcli d wifi connect '<ssid>' password '<password>'

Connect to a Hidden Network

$ nmcli c add type wifi con-name '<arbitrary_name>' ifname wlan0 ssid '<ssid>'
$ nmcli c modify '<arbitrary_name>' wifi-sec.key-mgmt wpa-psk wifi-sec.psk '<password>'
$ nmcli c up '<arbitrary_name>'

Miscellaneous

Compress file: zip -r <archied_name>.zip <original_folder>
Extract .zip file: unzip <archied_name>.zip
Get public IPv4: dig +short myip.opendns.com @resolver1.opendns.com
Setup UART for Raspberry Pi

Disable Login Shell over Serial
Enabel Serial Port Hardware

$ sudo raspi-config
[SELECT] 5. Interfacing Options
[SELECT] P6 Serial

Disable Bluetooth and Stop Bluetooth service

$ sudo nano /boot/config.txt
[ACTION] xuống cuối văn bản
[ACTION] paste "dtoverlay=pi3-disable-bt"

$ sudo systemctl disable hciuart

(để bật bluetooth trở lại > thay dtoverlay=pi3-enable-bt)

Reboot

$ sudo reboot

Scan các mạng wi-fi lân cận: sudo iwlist wlan0 scan
Thêm thông tin cấu hình vào:

$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

[ADD]
network={
ssid="<your_ssid>"
psk="<your_passwork>"
key_mgmt=WPA-PSK
}

[ACTION] CtrlX -> Y để lưu file

$ sudo iwconfig wlan0 essid "ID" key "Pass"

Tùy chỉnh chạy trương trình khi khởi động

$ sudo nano /etc/rc.local
$ sudo /etc/rc.local

Cài đặt múi giờ

$ sudo cp /usr/share/zoneinfo/Asia/Ho_Chi_Minh /etc/localtime

Chạy đoạn chương trình khi bật cửa sổ terminal

$ sudo nano /home/pi/.bashrc
[ADD] python3 -m pip install --upgrade pip

Sử dụng Camera trên Raspberry Pi3

Reference 1
Reference 2

Cấu hình cho Camera

Menu > Preferences > Raspberry Pi Configuration > Interfaces > Enable Camera > OK

Taking Picture

$ raspistill -o PictureName.jpg
$ raspistill -t 10000 -o PictureName.jpg
$ raspistill -w 800 -h 600 -t 10000 -o /home/pi/camera/PictureName.jpg

Capture Video

$ raspivid -o VideoName.mp4
$ raspivid -t 10000 -o VideoName.mp4
$ raspivid -w 320 -h 240 -fps 24 -t 25000 -o /home/pi/camera/VideoName.mp4

Remote Desktop and Raspberry Pi

$ sudo apt-get install xrdp

List file: ls
Ra màn hình desktop: cd ~/Desktop/
Truy cập thư mục: cd <folder_name>
Tạo thư mục mới: mkdir <folder_name>
Edit một file .xx: sudo nano <filename>.xx
Tải file từ internet: wget <link_file_download>
Thoát chương trình: ctrl + C
Giải nén file .tgz hoặc .tar.gz: tar -xvzf tenfile
Chạy file thực thi: ./tenfile
pwd : current directory
reset: Làm sạch Terminal
nano ten_file : Tạo file với Nano
ctrl+x sau đó nhập y và Enter để lưu file.
touch tenfile : Tạo nhanh file trống
mkdir tenthumuc (make directory): Tạo thư mục
cp filecu filemoi (copy): Sao chép file
cp -r thumuccu thumucmoi : Sao chép thư mục
mv tencu tenmoi (move): Đổi tên file/thư mục
rm tenfile (remove): Xóa file
rm -r tenthumuc : Xóa thư mục
rm -r * : Xóa toàn bộ thư mục
zip -r archive_name.zip folder_to_compress : Nén folder
unzip archive_name.zip : giải nén file zip
rm -rf ~/.local/share/Trash/* : empty trash
du -Sh <file> : Xem kích thước file
readlink -f <file> : Lấy đường dẫn tuyệt đối của file
ln -s <source.file> <softlink.file> : softlink (or symlink)
ln <source.file> <hardlink.file>: hardlink

20+ linux command for Data Science

Reference

Download dữ liệu từ internet

Description	Command
check version	`wget -v`	`wget --version`
help message	`wget -h [URL]`	`wget --help [URL]`
log tất cả các message của hệ thống vào logfile	`wget -o logfile [URL]`
tải trong background	`wget -b [URL]`	`wget --background [URL]`
append vào logfile	`wget -a logfile [URL]`
	`wget -i inputfile`	`wget -i inputfile [URL]`
	`wget -t number [URL]`
đặt số lần exception khi truy xuất lỗi		`wget --tries number [URL]`
tiếp tục tải file nếu file có khả năng tải tiếp tục	`wget -c [URL]`
khoảng thời gian s giữa các lần truy xuất, sử dụng các hậu tố #m cho phút, #h cho giờ, #d cho ngày	`wget -w number_in_seconds [URL]`
recursive retrieving	`wget -r [URL]`
Tải và lưu file với tên filename	`curl -o [filename] [URL...]`
Tải và lưu file với tên trong URL	`curl -O [URL...]`
Tiếp tục tải file đã bị dừng vì một số lý do	`curl -C - [URL...]`
Đặt ngưỡng trên cho tốc độ truyền (byte)		`curl --limit-rate [value] [URL...]`
tải file từ FTP server.	`curl -u <username>:<password> [FTP_URL]`
upload file tới FTP server	`curl -u <username>:<password> -T <filename> <FTP_Location>`
hiển thị code C tương ứng		`curl [URL...] --libcurl [filename]`
sử dụng proxy để truy cập URL	`curl -x [proxy_name]:[port] [URL...]`	`curl --proxy [proxy_name]:[port] [URL...]`
truyền file qua giao thức SMTP - send mails		`curl --url 'smtps://smtp.gmail.com:465' --ssl-reqd --mail-from 'example_mail@gmail.com' --mail-rcpt 'mary@gmail.com' --mail-rcpt 'eli@example.com' --use-ascii 'Luong Tan Dat' --upload-file namdotnet.txt --user 'example_mail@gmail.com:google' --insecure`
tra từ điển	`curl dict:[dictionary_URL]:[word] e.g: curl dict://dict.org/d:love`

Xem nội dung tập tin

Description	Command
xem n dòng đầu	`head -n [number_of_line] [filename]`
xem n dòng cuối	`tail -n [number_of_line] [filename]`
Đếm số từ, số dòng trong file	`cat [filename]
đếm số từ, số dòng, số byte dữ liệu	`wc [filename]`
đếm số từ	`wc -w [filename]`
đếm số line	`wc -l [filename]`

Sắp xếp và xóa trùng lặp trong 1 file dữ liệu văn bản.

$ sort [filename] [-o new_filename]
$ sort [filename] [--output new_filename]

Sắp xếp theo số hoặc chữ, không có tham số output thì xuất ra terminal

$ sort -u [filename] [-o new_filename]
$ sort --unique [filename] [--output new_filename]

Xóa các dòng trùng lặp

$ sort -f [filename] [-o new_filename]
$ sort --ignore-case [filename] [--output new_filename]

Sắp xếp không phân biệt chữ hoa chữ thường

$ sort -r [filename] [-o new_filename]
$ sort --reverse [filename] [--output new_filename]

Đếm tần suất xuất hiện của mỗi dòng text trong file.

$ sort [filename] | uniq -c
$ sort [filename] | uniq -c | awk '{print $2, $1}'

Kiểm tra, xóa dòng theo điều kiện (sử dụng Regex)

$ grep [pattern] [filename]

e.g:

$ grep "yêu" data.txt
$ grep "y[êế]u" data.txt

Tìm kiếm bằng regex

$ grep -i [pattern] [filename]

e.g:

$ grep -i "^anh" data.txt

Tìm kiếm không phân biệt chữ hoa chữ thường

$ grep [pattern] [filename] > [output]

Trích xuất các dòng thỏa mãn pattern

$ grep -v [pattern] [filename] > [output]

Trích xuất các dòng không thỏa mãn pattern
Xóa dòng dài hơn, ngắn hơn x ký tự
Kiểm tra encoding của một file văn bản

$ file [filename]

Convert giữa các kiểu encoding

$ iconv -f [from-encoding] -t [to-encoding] [input-file] -o [output-file]

xem các encoding mà iconv hỗ trợ

$ iconv -l

Xóa các dòng dữ liệu của file A có trong file B

$ grep -Fvxf [lines-to-remove] [all-lines] > [output]

Trộn ngẫu nhiên (Shuffle) các dòng

$ cat [file1] [file2] | shuf -o [output]

Gộp dữ liệu của nhiều file và trộn dữ liệu

$ sort -R [filename] -o [output]
$ sort --random-sort [filename] -o [output]
$ sort -R [file1] [file2] -o [output]
$ sort --random-sort [file1] [file2] -o [output]

Split file thành nhiều file nhỏ hơn

$split -l [number_of_line] [bigfile] [output_dir]/[prefix]

Code GPIO:

Cài đặt git-core: sudo apt-get install git-core
Thực hiện update bộ nhớ cache: sudo apt-get update
Tải thư viện wiringPi: git clone git://git.drogon.net/wiringPi
Vào thư mục vừa tải về: cd wiringpi
Lấy code mới nhất: git pull origin
Thực hiện build thư viện: ./build

#include<wiringPi.h>
#include<stdio.h>

//GPIO 17
#define LedPin 0
int main(void)
{
    if(wiringPiSetup() == -1)
    {
        printf("setup wiringPi failed!");
        return 1;
    }

    pinMode(LedPin, OUTPUT);
    printf("\n\n| Blink led with period 1s |\n\n");
    while(1)
    {
        //turn LED off
        digitalWrite(LedPin, LOW);
        printf("...Led is turned on\n");
        delay(500);
        //turn LED on
        digitalWrite(LedPin, HIGH);
        printf("...Led is turned off\n");
        delay(500);
    }

    return 0;
}

Chạy chương trình nháy led

gcc "input" -o "output"
gcc -o nhayLED nhayLED.c -lwiringPi
ls -l
sudo ./nhayLED

Code LED 7 thanh

#include<bcm2835.h>
#include<stdio.h>

#define PINA RPI_V2_GPIO_P1_11
#define PINB RPI_V2_GPIO_P1_12
#define PINC RPI_V2_GPIO_P1_13
#define PIND RPI_V2_GPIO_P1_15
#define PINE RPI_V2_GPIO_P1_16
#define PINF RPI_V2_GPIO_P1_18
#define PING RPI_V2_GPIO_P1_22
#define PINH RPI_V2_GPIO_P1_29

unsigned char numbers[10] = {0x40, 0x79, 0x24, 0x30, 0x19, 0x12, 0x02, 0x78, 0x00, 0x10};

void setup()
{
    bcm2835_gpio_fsel(PINA, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PINB, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PINC, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PIND, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PINE, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PINF, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PING, BCM2835_GPIO_FSEL_OUTP);
    bcm2835_gpio_fsel(PINH, BCM2835_GPIO_FSEL_OUTP);
}

void display(int value)
{
    bcm2835_gpio_write(PINA, (value & 0x01));
    bcm2835_gpio_write(PINB, (value & 0x02));
    bcm2835_gpio_write(PINC, (value & 0x04));
    bcm2835_gpio_write(PIND, (value & 0x08));
    bcm2835_gpio_write(PINE, (value & 0x10));
    bcm2835_gpio_write(PINF, (value & 0x20));
    bcm2835_gpio_write(PING, (value & 0x40));
    bcm2835_gpio_write(PINH, (value & 0x80));
}

int main()
{
    int i = 0;
    if(!bcm2835_init())
        return 1;
    
    setup();
    while(1)
    {
        display(numbers[i%10]);
        printf("Number %d\n", i);
        i++;
        bcm2835_delay(1500);
    }
    bcm2835_close();
    return 0;
}

Build and run

Gcc -o led7thanh led7thanh.c -l bcm2835
Sudo ./led7thanh

Giao tiếp với nút nhấn.

#include<wiringPi.h>
#include<stdio.h>

#define button 0 /* GPIO17 */
#define LED1 1 /* GPIO18 */
#define LED2 4 /* GPIO23 */

digitalWrite(LED1, HIGH);
int main(void)
{
    int _count;
    if(wiringPiSetup() == -1)
    {
        printf("Setup wiringPi Failed!\n");
        return -1;
    }
    pinMode(LED1, OUTPUT);
    pinMode(LED2, OUTPUT);
    pinMode(button, INPUT);
    while(1)
    {
        digitalRead(button);
        if(digitalRead(button) == HIGH)
        {
            digitalWrite(LED1, HIGH);
            digitalWrite(LED2, LOW);
        }
        else
        {
            digitalWrite(LED2, HIGH);
            digitalWrite(LED1, LOW);
        }
    }
}

Điều khiển GPIO bằng file hệ thống

B1. Truy vập vào thư mục gpio: cd /sys/class/gpio
B2. Tạo ra thư mục điều khiển gpio14: echo 14 > export
B3. Thiết lập chân output: echo out > direction
B4. Đưa chân lên mức cao (bật LED): echo 1 > value
B5. Đưa chân xuống mức thấp (tắt LED): echo 0 > value

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Lệnh cơ bản 1.

How to run sudo command without a password on a Linux or Unix

Secure Shell (SSH)

SSH ngrok

Local Port Forwarding

Remote Port Forwarding

Using `mosh` on macOS and Ubuntu involves installing the `mosh` package and then connecting to a remote server. Here are the steps for both platforms:

1. Install Mosh:

On macOS:

On Ubuntu:

2. Connect to Remote Server:

3. Using SSH Keys:

4. Specifying SSH Port:

5. Useful Options:

6. Exiting Mosh:

Cloudflare Warp

Create SSH tunel to a running colab notebook

Compress data using multiple CPU cores

`Tmpfs` and `Ramfs`

Add an additional hard drive

SCP command to Sercurely Tranfer Files

RSYNC (remote sync) in Linux

RSYNC Command Syntax:

Example

Linux tmux command

Tmuxinator configuration

Crontab

Wake On Lan

Tree command

Wireless Connection

Miscellaneous

20+ linux command for Data Science

Code GPIO:

Code LED 7 thanh

Giao tiếp với nút nhấn.

Điều khiển GPIO bằng file hệ thống

FilesExpand file tree

linux_command.md

Latest commit

History

linux_command.md

File metadata and controls

Lệnh cơ bản 1.

How to run sudo command without a password on a Linux or Unix

Secure Shell (SSH)

SSH ngrok

Local Port Forwarding

Remote Port Forwarding

Using mosh on macOS and Ubuntu involves installing the mosh package and then connecting to a remote server. Here are the steps for both platforms:

1. Install Mosh:

On macOS:

On Ubuntu:

2. Connect to Remote Server:

3. Using SSH Keys:

4. Specifying SSH Port:

5. Useful Options:

6. Exiting Mosh:

Cloudflare Warp

Create SSH tunel to a running colab notebook

Compress data using multiple CPU cores

Tmpfs and Ramfs

Add an additional hard drive

SCP command to Sercurely Tranfer Files

RSYNC (remote sync) in Linux

RSYNC Command Syntax:

Example

Linux tmux command

Tmuxinator configuration

Crontab

Wake On Lan

Tree command

Wireless Connection

Miscellaneous

20+ linux command for Data Science

Code GPIO:

Code LED 7 thanh

Giao tiếp với nút nhấn.

Điều khiển GPIO bằng file hệ thống

Using `mosh` on macOS and Ubuntu involves installing the `mosh` package and then connecting to a remote server. Here are the steps for both platforms:

`Tmpfs` and `Ramfs`