_mycompletion() {
local command_name="$1" # not used in this example
local current_word="$2"
local previous_word="$3" # not used in this example
# COMPREPLY is an array which has to be filled with the possible completions
# compgen is used to fi...
It is possible to save a Docker container's filesystem contents to a tarball archive file. This is useful in a pinch for moving container filesystems to different hosts, for example if a database container has important changes and it isn't otherwise possible to replicate those changes elsewhere. Pl...
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?yourdomain.com/.*$ [NC]
RewriteRule \.(gif|jpg|css)$ - [F]
This blocks all the links to '.gif', '.jpg' and '.css' files which are not from the domain name http://www.yourdomain.com.
Display alterna...
3.0
The most simple way is to use sorted():
let words = ["Hello", "Bonjour", "Salute", "Ahola"]
let sortedWords = words.sorted()
print(sortedWords) // ["Ahola", "Bonjour", "Hello", "Salute"]
or sort()
var mutable...
import fileinput
replacements = {'Search1': 'Replace1',
'Search2': 'Replace2'}
for line in fileinput.input('filename.txt', inplace=True):
for search_for in replacements:
replace_with = replacements[search_for]
line = line.replace(search_for, replace_with...
The method compareTo should be used to compare BigDecimals:
BigDecimal a = new BigDecimal(5);
a.compareTo(new BigDecimal(0)); // a is greater, returns 1
a.compareTo(new BigDecimal(5)); // a is equal, returns 0
a.compareTo(new BigDecimal(10)); // a is less, returns -1
Commonly you shou...
A powerful alternative to virtualenv is Anaconda - a cross-platform, pip-like package manager bundled with features for quickly making and removing virtual environments. After installing Anaconda, here are some commands to get started:
Create an environment
conda create --name <envname> pyth...
Applying a function to a collection/stream and creating a new collection/stream is called a projection.
/// Projection
var newReleases = [
[
"id": 70111470,
"title": "Die Hard",
"boxart": "http://cdn-0.nflximg.com/images...
Create a stream by selecting the elements from a stream that pass a certain condition is called filtering
var newReleases = [
[
"id": 70111470,
"title": "Die Hard",
"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.j...
A HAVING clause filters the results of a GROUP BY expression. Note: The following examples are using the Library example database.
Examples:
Return all authors that wrote more than one book (live example).
SELECT
a.Id,
a.Name,
COUNT(*) BooksWritten
FROM BooksAuthors ba
INNER JOIN Aut...
We can use 1,2,3.. to determine the type of order:
SELECT * FROM DEPT
ORDER BY
CASE DEPARTMENT
WHEN 'MARKETING' THEN 1
WHEN 'SALES' THEN 2
WHEN 'RESEARCH' THEN 3
WHEN 'INNOVATION' THEN 4
ELSE 5
END,
CITY
IDREGIONCITYDEPARTMENTEMPLOYEES_N...
PostgreSQL and SQLite
To create a temporary table local to the session:
CREATE TEMP TABLE MyTable(...);
SQL Server
To create a temporary table local to the session:
CREATE TABLE #TempPhysical(...);
To create a temporary table visible to everyone:
CREATE TABLE ##TempPhysicalVisibleToEveryo...
When results need to have some logic applied 'on the fly' one can use CASE statement to implement it.
SELECT CASE WHEN Col1 < 50 THEN 'under' ELSE 'over' END threshold
FROM TableName
also can be chained
SELECT
CASE WHEN Col1 < 50 THEN 'under'
WHEN Col1 > 50 AND Col1 ...
Sometimes when tables are used mostly (or only) for reads, indexing does not help anymore and every little bit counts, one might use selects without LOCK to improve performance.
SQL Server
SELECT * FROM TableName WITH (nolock)
MySQL
SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;...
Sometimes one wants to capture the records that have just been updated.
CREATE TABLE #TempUpdated(ID INT)
Update TableName SET Col1 = 42
OUTPUT inserted.ID INTO #TempUpdated
WHERE Id > 50
The method Kernel#autoload registers filename to be loaded (using Kernel::require) the first time that module (which may be a String or a symbol) is accessed.
autoload :MyModule, '/usr/local/lib/modules/my_module.rb'
The method Kernel#autoload? returns filename to be loaded if name is registere...
When files are not available, the require family will throw a LoadError. This is an example which illustrates loading optional modules only if they exist.
module TidBits
@@unavailableModules = []
[
{ name: 'CoreExtend', file: 'core_extend/lib/core_extend' } \
, { name: 'Fs' ...
The Kernel#load method will evaluate the code in the given file. The search path will be constructed as with require. It will re-evaluate that code on every subsequent call unlike require. There is no load_relative.
load `somefile`
