Run the following in your Terminal:
ps -ef | grep mongod | grep -v grep | wc -l | tr -d ' '
This will get you the number of
MongoDB processes running, thus if it is other than
0, then you have
MongoDB running on your system.
ps -ef | grep mongod part return all the running processes, that have any relation to the supplied string, i.e.
mongod, e.g. have the string in the executable path, have the string in the username, etc.
When you run the previous command, the
grep mongod also becomes a process containing the string
mongod in the
COMMAND column of
ps output, so it will also appear in the output. For that reason you need to eliminate it by piping
grep -v grep, which filters all the lines from the input that contain the string
So now you have all possible lines that contain string
mongod and are not the instances of
grep. What to do? Count them, and do that with
wc -l output contains additional formatting, i.e. spaces, so just for the sake of the beauty, run
tr -d ' ' to remove the redundant spaces.
As a result you will get a single number, representing the number of processes you