Fernando Ghinzelli

Linux

grep commands

# List text without comments (#)
grep -v '^#' file1 file2 file3 

Add a program to default path

# Create a symbolic link in /usr/local/lib
ln -s /opt/program/program.sh /usr/local/lib

Change permissions

chomod u+r | chmod g+r | chmod o+r | chmod ugo+r

Find patterns

grep "<pattern>" <filename>  
<command_output> | grep "pattern"

Find process ID

ps -A | pgrep code

Disk space

du -sh <directory_name> # Espaço de uma pasta

Convert to base64

echo -n 'user:pwd' | base64

Log in bash

#!/bin/bash
# redirect stdout/stderr to a file
exec &> logfile.txt 

DNS

• Clear DNS sudo systemd-resolve --flush-caches

SSH

• Generate Keys (~/.ssh/id_rsa) ssh-keygen

• Copy public keys to server ssh-copy-id -i ~/.ssh/id_rsa.pub username@servername

Create a new Item in the laucher menu

# create a new file in /usr/share/applications and save with this informations
[Desktop Entry]
Type=Application
Encoding=UTF-8
Name=<Sample Application Name>
Comment=<A sample application>
Exec=/opt/<application>
Icon=<application.png>
Terminal=false
Categories=Application

CentOS on Docker - Executar yum update

sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*

VNC

https://www.server-world.info/en/note?os=Ubuntu_19.04&p=desktop&f=5 https://www.tecmint.com/install-and-configure-vnc-server-on-ubuntu/

Links

Bash academy
Bash Begginners Guide
Bash Prog
Regex