Get the initial username which you used to login to your Linux system
If you need the initial user which you used to login to your Linux system or the time when you login you can do:
whoami
One purpose of this could be the .bashrc to show different Bash Prompts for root to different users:
if [ $(whoami) = "root" ]; then
PS1='${debian_chroot:+($debian_chroot)}\[\033[41;33m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
Related cards:
Rails: How to get the ordered list of used middlewares
Rails middlewares are small code pieces that wrap requests to the application. The first middleware gets passed the request, invokes the next, and so on. Finally, the application is invoked, builds a response and passes it back to the last middlew...
How to resize your boot partition when there is an encrypted partition after it
Boot partitions from installations prior to the 16.04 era are terribly small. When you install updates and encounter errors due to a full /boot
partition, consider risizing it.
If you can't do the steps described below, ask someone experienced ...
How to get the hostname of the current machine in Rails or a Ruby script
Use Socket.gethostname
. So for a machine whose hostname is "happycat", it will look like this:
>> Socket.gethostname
=> "happycat"
That should work right away for your Rails application. For plain Ruby, you first need to do:
requi...
RVM: Get rid of your system Ruby
If you worked with a system Ruby before switching to RVM, this system Ruby will be in your way when you switch between projects with/without RVM.
It's hard to get rid of your system Ruby entirely, but you can tell RVM to just use a given Ruby by ...
Making httpclient use the operating system's SSL cert store
The httpclient gem comes with a custom SSL cert store.
While an customizable, application-level cert store is great when you need to deal with broken or self-signed certificates, you usually want to use the c...
How to fix: Microphone recording levels are too quiet (or get lowered automatically)
If others on a call (Skype, SIP, ...) can not hear you loud enough, your volume levels are probably too low. Also, Skype may be changing your mixer levels.
Set a proper recording volume
- Open your mixer software (run
pavucontrol
). - Switc...
Yarn: How to recognize that you are using a different node version than your colleagues
The issue in this card can occur if the node_modules
directory is checked into your Git repository. We usually recommend to exclude node_modules
from version control.
In any case you should document which version of node to use in your pr...
Working on the Linux command line: How to use bookmarks for directories
Bookmarks for directories will be most helpful if you are forced to work in deeply nested projects. Then it's really helpful!
This makes use of the CDPATH
variable. Similar to the PATH
variable, which holds the list of directories which are s...
Using ngrok for exposing your development server to the internet
Sometimes you need to access a dev server running on localhost from another machine that is not part of the same network. Maybe you want to use your phone to test a web page, but are only in a guest WiFi. In the past, we often used [some port forw...