Show the name and version of your Linux distribution
To list the name and version of your Linux distribution, type the following:
cat /etc/*-release
Related cards:
Show the character set and the collation of your MySQL tables
To show the collation of your tables you have to login to the MySQL console and execute SHOW TABLE STATUS FROM database;
mysql> SHOW TABLE STATUS FROM test;
+-------------+--------+---------+------------+------+----------------+--------...
Change the name of your Ubuntu machine
In order to rename your Ubuntu box, replace all occurences of the the old name in the following two files:
/etc/hostname
/etc/hosts
After a reboot your hostname is changed. If you don't want to reboot your Ubuntu box you have to execute ...
RSpec: Leverage the power of Capybara Finders and Matchers for view specs
View specs are a powerful tool to test several rendering paths by their cases instead of using a more costing feature spec. This is especially useful because they become quite co...
git: find the version of a gem that releases a certain commit
Sometimes I ran across a GitHub merge request of a gem where it was not completely obvious in which version the change was released. This might be the case for a bugfix PR that you want to add to your project.
Git can help you to find the next gi...
ActiveRecord::RecordNotFound errors allow you to query the :name and :id of the model that could not be found
ActiveRecord::RecordNotFound
errors provide quite meaningful error messages that can provide some insight on application details. Consider the following:
ActiveRecord::RecordNotFound: Couldn't find Organisation::Membership with 'id'=12 [WHE...
Capistrano: How to find out which version of your application is currently live
When deploying, Capistrano puts a REVISION
file into your application's release directory. It contains the hash of the commit which was deployed.
If you want to know the currently deployed release, simply SSH to a server and view that file.
``...
Working on the Linux command line: Use the `tree` command instead of repeated `cd` and `ls`
The tree
command will show you the contents of a directory and all its sub directories as a tree:
>tree
.
├── a
│ ├── file_1.txt
│ └── file_2.txt
└── b
├── c
│ └── even_more.txt
└── more.txt
3 directories, 4 files
If...
Installing multiple MySQL versions on the same Linux with mysql-sandbox
Ubuntu has a package mysql-sandbox
that lets you install multiple MySQL versions into your user home:
- Install
mysql-sandbox
sudo apt install mysql-sandbox
- Download the version of MySQL you want to use from mysql.com:
<https://...
Security issues with hash conditions in Rails 2 and Rails 3
Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']
) or a hash (:conditions => { 'state' => 'draft' }
). The later is nicer to read, but has horrible security implications in some versions of Ru...
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 ...