How to redacted picture in MacOS

Select the area and press Delete button

ShredOS

Used ShredOS to clean old computer before go to electronic waste or recycling center.

It took nearly 7 hours to wipe just one round.

Install the Ubuntu after sanitize the hard drive.

Note to self – How to Clear the Terminal History on Linux or macOS

Copy from https://www.howtogeek.com/179022/how-to-clear-the-terminal-history-on-linux-or-mac-os-x/ as a note to self

Clear the Current Session's History
Your history can be broke down into two chunks. There's your current sessions' history, and there's your long-term history. Our first command, history -c, deals with the current session.

Clear All of Your Bash History
If you want to remove the entirety of your history, run the following command:
rm ~/.bash_history

Use open ~/.bash_history to view and edit

How to validate Libre Office on Mac

For a peace of mind, spend a minute to validate the downloaded file from internet.

Get information from https://download.documentfoundation.org/libreoffice/stable/7.0.4/mac/x86_64/LibreOffice_7.0.4_MacOS_x86-64.dmg.mirrorlist

File information
Filename: LibreOffice_7.0.4_MacOS_x86-64.dmg
Path: /libreoffice/stable/7.0.4/mac/x86_64/LibreOffice_7.0.4_MacOS_x86-64.dmg
Size: 252M (263941643 bytes)
Last modified: Fri, 11 Dec 2020 23:57:25 GMT (Unix time: 1607731045)
SHA-256 Hash: 0fcd83399609780013aee1acc805d1380434118d459829908aa409f7eb67c4e7
SHA-1 Hash: 443de571dad8e412e8b9e4be52ad5b249cc2627f
MD5 Hash: a36fd3c1d5e8935e4732cbf0f826a821
BitTorrent Information Hash: 636f6abbb3ed784831da6385686b1577538e8a39
PGP signature available

Run this command on MacBook: 
openssl dgst -sha256 LibreOffice_7.0.4_MacOS_x86-64.dmg
SHA256(LibreOffice_7.0.4_MacOS_x86-64.dmg)= 0fcd83399609780013aee1acc805d1380434118d459829908aa409f7eb67c4e7

Compare this SHA256 value against with value got from LibreOffice web site above.

How to validate KeePassXC on Mac

Per https://keepassxc.org/download/#mac

Before installing KeePassXC, you should always verify that your download matches the signature that is published alongside the release package! 

openssl dgst -sha256 KeePassXC-2.6.2-2.dmg

Compare the result with value in KeePassXC-2.6.2-2.dmg.DIGEST downloaded from KeePassXC web site

How to make multiple profiles in Mozilla Firefox

Multiple profiles is not visible as in Microsoft Edge Chromium, according to https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Multiple_profiles

Enter "about:profiles" to create a new profile or update. 

Validate Downloaded Keepass 2.45 on Windows 10

Ran CertUtil and compare with value on https://keepass.info/integrity.html

C:\>certutil -hashfile KeePass-2.45.zip SHA256
SHA256 hash of KeePass-2.45.zip:
d414db9d411acbafd4e1b5faa8605ad7a28829f1814ce779142ffbd5ca9c3794
CertUtil: -hashfile command completed successfully.

C:\>certutil -hashfile KeePass-2.45-Setup.exe sha256
SHA256 hash of KeePass-2.45-Setup.exe:
9058cc9d44129e8c2c902e21f8678974b789ecd8f9d6add81c98fbeaf9794e23
CertUtil: -hashfile command completed successfully.

Per https://keepass.info/integrity.html:

If you want to verify the integrity of your downloaded file, you can hash the file (for instance with one of the following utilities: Visual Hash Calculator, ReHash, MD5sums) and check whether the computed hash matches the one listed below.

OpenPGP signatures can be verified with the public key.

KeePass-2.45.zip:
MD5: 5E838DA8 5050A5C6 DFABB0D6 57C10025
SHA-1: 7EFDC08F BC69D911 A40D29FC 3CA744D2 763C49DF
SHA-256: D414DB9D411ACBAFD4E1B5FAA8605AD7A28829F1814CE779142FFBD5CA9C3794
Size: 3039842 B
Sig.: [OpenPGP ASC]

KeePass-2.45-Setup.exe:
MD5: 5BAAADAA 21098D63 5BB37782 CD9E6446
SHA-1: 68B0A6E5 042A2524 530156C9 34D47E20 C3BC684A
SHA-256: 9058CC9D44129E8C2C902E21F8678974B789ECD8F9D6ADD81C98FBEAF9794E23
Size: 3171656 B
Sig.: [OpenPGP ASC]

My Favorite Password Manager

For security, we need a strong password and difference password for difference place. How can I remember all my passwords? My memory is no longer good. 

Solution is using password manager. KeePass is my favorite password manager. To me, it's the best. It's free. It's open source. It may be more secure than other paid password manager.

In Mac OSX, I used KeePassX but now using KeePassXC. Both ported from KeePass.

My Development Computer 2017

Here are the essential tools I put in my seven years old personal laptop for my application development during evening and weekend as of July 2017. Most of them are open source and free. My other development machine at work is much better and powerful than this (Intel i7 CPU and 16GB RAM).

1. Mozilla Firefox
2. Google Chrome
3. Notepad++ is a free  source code text editor.
4. WinMerge for compare and merge files.
5. 7-Zip (Compress and decompress files)
6. KeePass the free, open source, light-weight and easy-to-use password manager. I don't need to remember password for each web sites or applications.
7. Python 3.6  This programming language is powerful and fast. According to TIOBE Index for July 2017, Python is one of top five popular programming languages. 
8. LibreOffice is a powerful free, open source and cross platform office suite. I used it on other PC Windows, my MacBook Pro, and Ubuntu Linux.
9. SQL Server 2016 SP1 Developer Edition SQL Server Developer Edition is a free download for Visual Studio Dev Essentials members and for development and testing only, and not for production environments or for use with production data per Microsoft SQL Server blog
10. Microsoft Visual Studio Community 2017 (Free version for an individual developer or small business, not for corporate)
11. Microsoft Visual Studio Code. This is free, open source, and runs everywhere. It loaded faster than Visual Studio.
12. Git for Windows. It's a free and open source distributed version control system.
13. Node.js® is a JavaScript runtime built on Chrome's V8 JavaScript engine.
14. VLC is a free and open source cross-platform multimedia player and framework that plays most multimedia files as well as DVDs, Audio CDs, VCDs, and various streaming protocols.
15. Greenshot is the most awesome tool for making screenshots you can get on your Windows PC. It's is better than built-in application Snipping Tools. I can blackout or obscure portion of screen easily.
16. FileZilla® Open source FTP software.

In addition to C# and Microsoft SQL Server, I will spend my spare time to work on Python and Node.js.

Check for Conexant Audio Driver Keylogger

Even you don't have HP computer, to be safe, you should make a quick check to see your computer have Conexant log file: MicTray.log or any file name begin with MicTray

Further reading:

1. Arstechnica: HP laptops covertly log user keystrokes, researchers warn
2. SpiceWork: Keylogger in HP audio driver
3. InfoWord: HP computer owners: Check for the MicTray Conexant keylogger

ROBOCOPY

I did not know this command ROBOCOPY until few months ago. I'm used to XCOPY on Microsoft Windows PC. But this one is better.

Instead using: XCopy D:\Temp C:\Temp /secdykhr
I use: RoboCopy D:\Temp C:\Temp /E /XX /XO /DST /DCOPY:T /R:3 /NP /LOG+:C:\Temp\robocopy.log

On Windows XP, you must download it from Microsoft.

How to Install Windows 10 Technical Preview on Oracle VirtualBox Virtual Machine

I'm enjoy learning a new thing everyday. To learn more about Windows 10, I'm using Oracle VirtualBox Virtual Machine to install. Since VirtualBox 4.3.16 Oracle VM VirtualBox Extension Pack (VirtualBox Guest Addition) not work with Windows 10 yet, I cannot see a full screen and using a shared folder. Hope the next version of VirtualBox will work well with Windows 10

How to mount an ISO image file on Windows 7

There is a free unsupported utility from Microsoft ( http://www.microsoft.com/en-us/download/details.aspx?id=38780 ) called Virtual CD-ROM Control Panel that enables users of Windows XP, Windows Vista, and Windows 7 to mount ISO disk image files as virtual CD-ROM drives.

I downloaded it, unzipped, moved driver to Windows System folder, configured it and attempted to use. Finally, remove it from my test computer.

Next, go to http://www.slysoft.com/en/virtual-clonedrive.html to get SlySoft Virtual Clone Drive, a freeware. After installed it, I can open the ISO image disk file from Windows Explorer. Virtual Clone Drive is easy to install and use.

Buying a new laptop

If you are going to buy a laptop using Microsoft Windows, make sure it has Windows 7. Windows 8 is not good, hard to use and took a lot of time to learn. Thus Microsoft force to make Windows 8.1 as a new free upgrade.

http://www.extremetech.com/computing/155747-windows-8-1-will-be-a-free-upgrade-will-begin-public-beta-testing-on-june-26.

Also, make sure the CPU support supports Intel® Virtualization Technology (Intel® VT) along with many advanced technologies as I mentioned on my previous post. I preferred Intel® Core™ i3, i5 or i7 processor.

Your laptop should have:

• 15.6" monitor screen. 
• At least 1.9 GHZ Intel® Core™ i3 processor 
• At least 4 GB RAM expandable to 8GB or 16GB
• Built-in high-speed wireless 802.11b/g/n and Gigabit Ethernet LAN. 
• Two or more USB ports.
• Built-in front camera.
• At least 3 hours battery.

Compare Files and Folders

In Linux or Mac OS/X, using diff command at the terminal.

To compare two folders:
diff -rq folder1 folder2

To compare two files:
diff file1 file2
diff 'first file' 'second file'

For more options:
diff --help

For Microsoft Windows computer, use WinMerge, an open source software, to compare and merge files and folders.

My New Toy

My new toy is a 13-inch MacBook Pro. It took me a lot of time to think over which Mac (Mac Mini, MacBook Air, 13-inch MacBook Pro, or 15-inch MacBook Pro) would be my next working computer. I needed a new computer with a bigger hard drive, longer battery life, and support Intel Virtual Technology. I also needed to familiarize myself with Mac OS X as more people are using Mac OS and iOS. I would have preferred a 15-inch MacBook Pro but I did not want to overspend on a Mac product. Yes, Apple products are high quality but they are too expensive.

My first impression with my MacBook Pro: I can utilize second band 5GHz wireless network (801.11a / 801.11n). Next, it just had only one or two updates, which took a few minutes to install after I initialized the new computer. My Dell Windows 7 took an hour to update. After a system update, I installed Adobe Flash, Java Development Kit SE, LibreOffice, Android SDK, and Eclipse IDE, and Virtual Box. Last, after learning how to use the Multi-Touch track pad, I really like it.

How about the boot time? It is fast but it still cannot beat Ubuntu 11.10 running on a slower CPU, Intel Pentium Dual-Core 2.3GHz.

Linux turned 20 on Aug. 25

The first Linux distro I played around was Red Hat Linux 5.2 in 1999.

After that, I backed to Windows for both professional development and personal desktop application usage. Before that I developed a FoxBase+ application on SCO/Unix in 1990 for a year. I tried again with another distro in 2002, I guessed. Still not a right time, back to Windows. Today, I'm using Ubuntu Linux on daily basic. I'm still using Microsoft Windows for software development (ASP 3.0, ASP.NET, C#, Microsoft SQL 2008, IIS 7, TFS) at work. Anything else, Linux. Android development: Linux. Web develop using PHP, Python, MySQL: Linux. Desktop word processing: Linux. Web browsing: Linux. Listen to music on computer: Linux.

How to Take a Screenshot

Microsoft Windows
For any Windows version:

1. Press  (Print Screen) key to capture a screenshot of the entire desktop and places it in the clipboard. To capture only the active window, press both   and keys. 
2. Press V to paste the screenshot into other application like Paint or GIMP or Microsoft Word or LibreOffice Writer. 

Another option for Windows Vista and Windows 7 user: Use Snipping Tool to capture screen shots . It a free utility included in Windows Vista and Windows 7

Ubuntu Linux
Press to take a screenshot and save

iOS
Pressing and holding the Home button and the Sleep/Wake button. The screen will flash and the picture will be stored in PNG format in the "Camera Roll" on the iPhone or in "Saved Photos" on the iPod touch. The screenshot feature is only available with iOS 2.0 and later.

Mac OS X
On Mac OS X, a user can take a screenshot of an entire screen by pressing ⌘ Cmd+⇧ Shift+3, or of a chosen area of the screen by ⌘ Cmd+⇧ Shift+4. This screenshot is saved to the user's desktop, with one PNG file per attached monitor.

64-bit Operating System

I'm not pay much attention to 64-bit operating system until few months ago. At that time, I needed to evaluate  Windows Server 2008 R2 Operating System and tested our applications in that 64-bit operating system.

After I downloaded a trial copy from Microsoft site, I could not install it as a VirtualBox virtual machine on my 32-bit Ubuntu 10.10 desktop. So, backed up my stuff before installed 64-bit Ubuntu 11.04 beta on my laptop to host 64-bit guest operating system. It still not work. I did some research on the internet, someone said need to enable virtualization in BIOS. My BIOS did not have it. According to the specification from Intel web site, my CPU did not have Intel® Virtualization Technology (Intel® VT). Too bad. I could not install 64-bit guest operating system on my current 64-bit PC.

Let not quit yet. Try VMWare Player. Same problem. I could not install Windows Server 2008 R2 64-bit  as a guest virtual machine.

This experience taught me a lesson: Your next PC should have virtualization technology. As I mentioned in my blog last month, my next PC will be a Mac. 15-inch MacBook Pro using quad-core Intel Core i7 processor. This CPU supports Intel® Virtualization Technology (Intel® VT) along with many advanced technologies.

While waiting to acquire a new PC, I loaded Windows Server 2008 Standard (32-bit) on my 64-bit PC running 64-bit Linux Operating System to evaluation and test our applications. Below is the picture of my desktop:

Two virtual machines: Windows Vista and Windows Server 2008 Standard run on Ubuntu 11.04 desktop.

My Next PC

My next Personal Computer (PC) will be a Mac. The first PC I used was an Apple computer, Apple II, when I was in college. After a quarter of a century using Microsoft Operating Systems (DOS, Windows), I'm switching to Linux. I'm so happy with Ubuntu and Open Source applications. I pick Mac not because it's better than Microsoft Windows PC or Linux PC. Mac is so expensive! The lowest MacBook is $999 while the you can get the Microsoft Windows PC for about $400. With a MacBook Pro, I can program or test number of difference projects: iPhone mobile applications, Android mobile applications, PHP web-based applications, Python programs, mySQL,... Using VirtualBox on MacBook Pro, I can run Windows and Linux applications on guest machines. I must buy a Mac machine because Mac/OS license is not allow to run on virtual machine. It must run on Apple hardware.