MacOS

Aliases on shell
Since .bashrc is not working, i managed to do some tricks 
 Edit /etc/profile and add the following lines....... 
  

Dealing with ISO Files with hdiutil
Creating an iso file from a directory 
 hdiutil makehybrid -iso -joliet -o output_image.iso input_directory/ 
 Mounting an iso file into /Volumes/ 
 hdiutil mount source_image.iso 
  

Writing image to SD card
These are the steps to write an raspberry pi OS image to an SD card on MacOS 
 1. Insert card on reader 
 Identify the disk number 
 diskutil list 
 2. Unmount the disk 
 unmountDisk /dev/disk2 
 3. Write the image 
 sudo dd bs=1m if=hassos_rpi3-2.12.img of=/dev/rdisk2 conv=sync 
 4. Eject card 
 sudo diskutil eject /dev/rdisk2 
 Done! 
   
 https://www.raspberrypi.org/documentation/installation/installing-images/mac.md 
  

DNS Cache clear
  
 dscacheutil - flushcache 
 sudo killall - HUP mDNSResponder 
 https://www.siteground.com/kb/how_to_clear_the_local_dns_cache_in_mac_os/