command inside $() in bash script

Question

I'm new to linux. I'm seeing a bash command (is that even the right term?) that sets `JAVA_HOME` environment variable at the prompt: ``` export JAVA_HOME =$(readlink -f /usr/bin/java |sed "s:bin/java::") ``` I know what the command inside `$()` does. But what is the `$()` for? It failed if I didn't include it. Obviously googling `$()` doesn't work very well.

Accepted Answer

It's used to get the output of the `readlink` command. For example:

```
cnicutar@lemon:~$ os=$(uname)
cnicutar@lemon:~$ echo $os
Linux
```

command inside $() in bash script

Solution

Problem