If you want to run a database tool for MySQL from the command line it would seem you cannot avoid including the password using a –password argument. The problem is that the whole command line while the command is being run will be visible to any other user of the same server using the “ps” command.
The solution is to specify the password in a “option” file (as MySQL calls it). This is a file named .my.cnf (note the dot at the beginning) in your account’s root folder (ie: /home/myname/ or /root/ for the root user) with the following contents:
[client] password=password
Of course replace the “password” with your real password. You should als make this file only readable by yourself with the following command:
chmod 600 .my.cnf
That ensures that nobody else can open the file (well except root if you are not an admin, but the root user would have access to everything anyway).
Now whenever you run a MySQL tool (mysql, mysqldump, etc) the password from the option file will be automatically used. If your username matches the MySQL username you also don’t need to specify a username. This can be very useful especially as root, when you need to do daily backups using mysqldump for example.
This tricks works in a similar way for PostgreSQL: put a file named .pgpass with the following contents:
hostname:port:database:username:password
You can use an asterisk (*) to match “any” value (wildcard), for example for port or database.