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.

Answer 1

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

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