Nan Hua questions

• How to use stdbuf on a bash function
• How to use detect failure in command substitution
• How to filter a bash array
• How to kill a background process created in a script
• How to convert a list by mapping an element into multiple elements in python?
• How to explain this sizeof result when inheriting from an empty class
• What does "|&" mean in Bash?

Nan Hua answers