jgomo3

/*
To test that the Linux framebuffer is set up correctly, and that the device permissions
are correct, use the program below which opens the frame buffer and draws a gradient-
filled red square:

retrieved from:
Testing the Linux Framebuffer for Qtopia Core (qt4-x11-4.2.2)

http://cep.xor.aps.anl.gov/software/qt4-x11-4.2.2/qtopiacore-testingframebuffer.html
*/

jgomo3

README

Services declared as oneshot are expected to take some action and exit immediatelly (thus, they are not really services, no running processes remain). A common pattern for these type of service is to be defined by a setup and a teardown action.

Let's create a example foo service that when started creates a file, and when stopped it deletes it.

Define setup/teardown actions

Create executable file /opt/foo/setup-foo.sh:

jgomo3

;; Code folding
(add-hook 'ruby-mode-hook
          (lambda () (hs-minor-mode)))

(eval-after-load "hideshow"
  '(add-to-list 'hs-special-modes-alist
                `(ruby-mode
                  ,(rx (or "def" "class" "module" "do" "{" "[")) ; Block start
                  ,(rx (or "}" "]" "end"))                       ; Block end
                  ,(rx (or "#" "=begin"))                        ; Comment start

jgomo3

unless Rails.env.production?
  connection = ActiveRecord::Base.connection
  connection.tables.each do |table|
    connection.execute("TRUNCATE #{table}") unless table == "schema_migrations"
  end

  sql = File.read('db/import.sql')
  statements = sql.split(/;$/)
  statements.pop

jgomo3

#!/bin/bash

# NB: First install nscd with sudo apt-get install nscd

# run this command to flush dns cache:
sudo /etc/init.d/dns-clean restart
# or use:
sudo /etc/init.d/networking force-reload
# Flush nscd dns cache:
sudo /etc/init.d/nscd restart

jgomo3

How to delete a file from a Git repository, but not other users' working copies

Suppose you have, by mistake, added your IDE's project folder (you know, these .idea folders with all kinds of local paths and configuration data and settings in it) to the Git repository of your project. (We're talking about a whole folder here, but the same rules apply to individual files as well.)

Of course, you only realize that two days after the fact and have already pushed it, and your colleagues have already pulled it. They use the same IDE as you do, so whenever they change a setting or fix paths, they can either

• commit that, causing nasty merge conflicts for you and others or
• ignore the changes and carry around a modified file until the end of time without ever committing it.

Why .gitignore won't help

jgomo3

import psycopg2 as pg

from io import BytesIO
from collections import defaultdict
from contextlib import contextmanager
from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT, ISOLATION_LEVEL_READ_COMMITTED

READ_COMMIT = ISOLATION_LEVEL_READ_COMMITTED
AUTO_COMMIT = ISOLATION_LEVEL_AUTOCOMMIT