Note to self: In order to see which commands (latest on top) were used to create a docker image run:
docker history --no-trunc --format 'RUN {{.CreatedBy}}' <image>
note to self: sometimes it happens that applications cannot find a camera on my system, although it is definitely built in and not broken. This can be solved by stopping all applications that may be using the camera and then in a terminal run
sudo killall VDCAssistant thanks to http://osxdaily.com/2013/12/27/fix-there-is-no-connected-camera-error-mac/ for this solution (check that link for further details)
note to self: when I need to access the docker host from within a container running in Docker for Mac, the hostname is docker.for.mac.localhost.
note to self: when searching a file or directory in OSX it is possible to show or hide the hidden files with the Cmd-Shift-period shortcut
note to self:
to set up a virtual host named viho for local web development testing on OSX El Capitan (and probably earlier):
define an alias name in /etc/hosts: 127.0.0.1 localhost viho ::1 localhost viho setup the virtual host configuration file /etc/apache2/other/viho.conf: <VirtualHost *:80> DocumentRoot "/path/to/where/the/files/are" ServerName viho </VirtualHost> browse to http://viho/ and enjoy.
Note to self:
To start or stop the Apache webserver on Mac OSX El Capitan, use the terminal:
sudo apachectl start sudo apachectl stop sudo apachectl restart The configuration is found in /etc/apache2/httpd.conf. The default DocumentRoot directory is /Library/WebServer/Documents. Additional configuration files should be put in /etc/apache2/other/*.conf files.
Note to self: When using Spring-Boot, use application.conf as a base configuration for the needed values. Configuration values for the specific profile go into the application-<profile>.config file.
Profiles are activated by using either the -Dspring.profiles.active=<profile> VM flag or --spring.profiles.active=<profile> commandline arg.
I just need to completely wipe two hard disks (/dev/sda and /dev/sdb) in an old linux computer. To do this I booted a knoppix system and then ran the following commands:
shred -vfz /dev/sda shred -vfz /dev/sdb
to keep in mind:
Overloading is the creation of a method in a class with the same name as an already existing method, but with different arguments. Overwriting is the creation of a method in a derived class with the same name as an already existing method in the base class and with the same arguments