meiwin

// sample codes for animating calayer's opacity
CABasicAnimation * animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
animation.fromValue = [NSNumber numberWithValue:0];
animation.toValue = [NSNumber numberWithValue:1];
targetLayer.opacity = 1; // must be set, otherwise targetLayer opacity will not be updated, even after animation is completed.
[targetLayer addAnimation:animation forKey:@"opacity"]; // the key "opacity" must match keyPath being animated.

meiwin

// as seen in http://www.cocoanetics.com/2012/02/caching-caches/
// benefits: thread-safe

- (id) cachedObject
{
  static dispatch_once_t onceToken;
  static id objectToCache;

  dispatch_once(&onceToken,^{
    objectToCache = ...; // create the object

meiwin

-- Write a SQL query that will result in full table scan.
  select *
  from   transaction_journal
  where  ucase(Receiver) = 'FOO'

-- Write a SQL query that can introduce a deadlock.
  select *
  from   transaction_journal
  for update
  ;

meiwin

# Create a single line script that returns the number of httpd processes that are running on the current machine
ps -e | grep httpd | grep -cv grep

# From the current folder (/tmp), provide some bash commands that will rename all the *.txt files in mig33/inner/ to *.dat
for fn in ./mig33/inner_folder/*.txt; do mv "$fn" "${fn/.txt}.dat"; done

meiwin

-- Write a sql query that will return a list of duplicate phone numbers and the duplication count
  select PhoneNumber, count(*) count
  from   TheTable
  group by PhoneNumber
  having count(*) > 1
  ;

-- Write a sql query that will return a list of IDs with duplicate phone numbers
  select ID
  from   TheTable

meiwin

// Write java program that:
// takes its input from two files and prints out lines that exists in both files
package mig33;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;

meiwin

/**
 * In the language of your choice, write a function which, taking a positive integer n as input,
 * finds all sets of numbers that sum up to n.
 * 
 * For example, n=4, we have:
 * 4
 * 3,1
 * 2,2
 * 2,1,1
 * 1,1,1,1

meiwin

////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
//
//  NSManagedObject+AutoUpdating.h
//  Piggie
//
//  Created by Meiwin Fu on 14/5/12.

meiwin

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

	<modelVersion>4.0.0</modelVersion>
	<groupId>com.yourcompany</groupId>
	<artifactId>yourartifact</artifactId>
	<version>1.0.0</version>
	<packaging>jar</packaging>

	<dependencies>

meiwin

keytool -import -alias <alias> -file <servercert.crt> -storepass <password> -keystore <keystore-file>