Command Line – What Does “$$” Mean in the Shell? command line What does the output of the command below mean? (result is positive integer) echo $$ Best Answer The $$ variable in bash and other shells contains the process id of the shell. See this Stack overflow question and this one also has more detail about what it is more precisely, and commands similar to it. Related SolutionsCommand-Line – What Does `~/` Mean in Filesystem? ~/ is shorthand for the current user's home folder. So if your user name is "foobar" it expands to /home/foobar/ Command Line ./ – What Does ./ Mean in Command Line? In Unix/linux . means the current directory in your case /etc/mds-1.2-beta4/sana/config/etc/Gapache2. There are also many shortcuts like: ..: parent directory (/etc/mds-1.2-beta4/sana/config/etc/) ~: home folder So to move all folders and files from /etc/mds-1.2-beta4/sana/config/etc/Gapache2 to /etc/apache2/sites-available, the command will be like this mv ./* /etc/apache2/sites-available/ UPDATE: This link is a good resource for basic UNIX commands Related QuestionCommand-Line – What Does `~/` Mean in Filesystem?Command Line ./ – What Does ./ Mean in Command Line?Find Command {} \; – What Does {} \; Mean in Find Command?Bash Command Line – What Does the ‘-‘ in ‘bash -‘ Mean?Ubuntu – What does ‘(:0)’ in the output of the command ‘who’ meanCommand-Line – Meaning of the Hyphen ‘-‘ in ‘tar xzf -‘
Best Answer
The
$$
variable in bash and other shells contains the process id of the shell.See this Stack overflow question and this one also has more detail about what it is more precisely, and commands similar to it.