What is the difference between backticks and $() in bash script? [duplicate]

问题

This question already has answers here:

What is the difference between $(command) and `command` in shell programming? (6 answers)

Closed 5 years ago.

I see in bash scripts two different forms which seems to do the same:

`some command`

and

$(some command)

What is the difference between the two, and when should I use each one of them?

回答1:

There is no semantic difference. The backtick syntax is the older and less powerful version. See man bash, Section "Command Substitution".

If your shell supports the $() syntax, prefer it because it can be nested.

来源：https://stackoverflow.com/questions/8941381/what-is-the-difference-between-backticks-and-in-bash-script