$() vs () bash

$() vs `` bash

$() or `` is called command subsitution

They are the same. Command subsitution allows the output of a command to 
replace the command identifier.

() vs {} bash

() 
- Placing a list of commands between parentheses causes a subshell environment
to be created, and each of the commands in list to be executed in that subshell.
Since the list is executed in a subshell, variable assignments do not remain 
in effect after the subshell completes.

{}
- Placing a list of commands between curly braces causes the list to be executed
in the current shell context. No subshell is created. The semicolon (or newline)
following list is required.

$() vs () bash

$(cmd) substitutes the result of cmd as a string, whereas (cmd; cmd) run a list of commands in a subprocess.

If you want to put the output of one or more commands into a variable use the $( cmd ) form.

However if you want to run a number of commands and treat them as a single unit use the () form.

The latter is useful when you want to run a set of commands in the background.

Source: stackoverflow.com

Similar codes

0 vote223 views1 answer
Failed to start docker.service: Unit docker.service is masked
Shell/Bash
2 votes229 views2 answers
Solana install
Shell/Bash
1 vote216 views1 answer
Yarn .gitignore for not Zero Installs
Shell/Bash
0 vote243 views1 answer
Zsh get first line
Shell/Bash
0 vote232 views1 answer
Bash create file with content
Shell/Bash
6 votes253 views2 answers
Remove directory powershell
Shell/Bash
0 vote239 views1 answer
Path too long while extracting zip file
Shell/Bash
0 vote248 views1 answer
Bash monitoring background jobs
Shell/Bash
0 vote213 views1 answer
Install clasp
Shell/Bash
2 votes236 views3 answers
Install vmware tools from terminal
Shell/Bash