willl keep all usefull commands here

commands

 # for setting node path in windows
 setx NODE_PATH "%NODE_PATH%;C:\Users\winbdows 7\AppData\Roaming\npm\node_modules"

to kill particular port.
sudo npx kill-port 5432

clear memory cache from Linux ubuntu.
sync; echo 3 | sudo tee /proc/sys/vm/drop_caches

for renew the letsencrypt certificates.

sudo certbot renew

Create alias in ubuntu

nano ~/.bashrc

write something alias like below.

alias apachelog='cd /var/log/apache2'
alias cronlog='cd /var/log/mysite/cron'
alias egrep='egrep --color=auto'
alias fdate='date "+%Y%m%d.%H%M%S"'
alias fgrep='fgrep --color=auto'
alias grep='grep --color=auto'
alias l='ls -CF'
alias la='ls -A'
alias ll='ls -alF'
alias ls='ls --color=auto'
alias n='nano'
alias site='cd /var/www/vhosts/mywebsite/httpdocs'
alias sitelog='cd /var/log/mywebsite/httpdocs'
alias findinsite="searchin(){ find /var/www/vhosts/mywebsite/httpdocs/ -xdev \( -path '*/.git/*' -o -path '*/.svn/*' -o -path '*/assets/css/*' -o -path '*/assets/js/*' \) -prune -o -type f -exec grep -H -e \"\$*\" {} +;}; searchin"
alias findincrm="searchincrm(){ find /var/www/vhosts/mywebsite/crm-v2/ -xdev ! -path '/var/www/vhosts/mywebsite/crm-v2/.git/*' ! -path '/var/www/vhosts/mywebsite/crm-v2/old_vendor/*' -type f -exec grep -H -e \"\$1\" {}>

After saving the file, please run source cmd to get it executable.

source ~/.bashrc

then you can run this directly like
findinsite HelloWorld

for renew the letsencrypt certificates.

sudo certbot renew

To check SSL Date range:

echo | openssl s_client -connect 13.xxx.xxx.91:443 2>/dev/null | openssl x509 -noout -dates

Find all files based on extensions related

find . -name \*.log -ls | sort -r -n -k7