kconner

macOS Internals

Understand your Mac and iPhone more deeply by tracing the evolution of Mac OS X from prelease to Swift. John Siracusa delivers the details.

Starting Points

How to use this gist

You've got two main options:

jasonhorner

with schema_info
as (SELECT t.table_catalog
         , t.table_schema
         , t.table_name
         , (
    SELECT
                c.column_name,
                c.ordinal_position,
                CASE
                    WHEN c.DATA_TYPE IN ('varchar', 'char', 'varbinary', 'binary') THEN

devigned

#!/usr/bin/env bash

set -euf -o pipefail

group="habitat-k8s"
location='westus'
vm_name="habitat-dev"
cluster_name="k8s-cluster"
name_prefix="habk8s"
new_name=$(echo $(mktemp -u ${name_prefix}XXXX) | tr '[:upper:]' '[:lower:]')

joepie91

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

• Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
• Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
• If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
• If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

ursuad

Kafka Topics

List existing topics

bin/kafka-topics.sh --zookeeper localhost:2181 --list

Describe a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --describe --topic mytopic

Purge a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

... wait a minute ...

malbarmavi

select * from master.dbo.sysdatabases;

use DataBaseName;
select * from information_schema.tables;
select TABLE_NAME 'Table Name',COUNT(COLUMN_NAME) 'Column Count'  
from information_schema.COLUMNS group by TABLE_NAME order by [TABLE_NAME];


select @@CONNECTIONS;

lumengxi

.PHONY: clean-pyc clean-build docs clean
define BROWSER_PYSCRIPT
import os, webbrowser, sys
try:
	from urllib import pathname2url
except:
	from urllib.request import pathname2url

webbrowser.open("file://" + pathname2url(os.path.abspath(sys.argv[1])))
endef

arttuladhar

Kitchen Commands

kitchen list
kitchen create
kitchen destroy
kitchen login <InstanceName>

vpack

Same as Screen but better

screen split commands

<ctrl> a - enter command mode
S - split uppercase
Q - close - uppercase
| - vertical split
tab - tab to other windows

chrissimpkins

Use these rapid keyboard shortcuts to control the GitHub Atom text editor on macOS.

Key to the Keys

• ⌘ : Command key
• ⌃ : Control key
• ⌫ : Delete key
• ← : Left arrow key
• → : Right arrow key
• ↑ : Up arrow key