All posts by admin

How to Set File Permissions for ASP.NET Website on Windows

August 11, 2023 admin Leave a comment

Problem:

You have ASP.NET website on Windows.
Your website application pool name is mysite.com.
Your website physical location is D:\inetpub\wwwroot\mysite.com.
Your website physical data location is D:\mysite_data.
Your website users cannot upload or modify website files.
Your website users cannot upload or modify website data files.

Solution:

1. Open cmd.exe as Administrator and execute the command below.

icacls "D:\inetpub\wwwroot\mysite.com" /grant "IIS AppPool\mysite.com":(OI)(CI)F /T
icacls "D:\mysite_data" /grant "IIS AppPool\mysite.com":(OI)(CI)F /T

This command give full permissions against D:\inetpub\wwwroot\mysite.com and all sub-directories and files, and against D:\mysite_data and all sub-directories and files to mysite.com user.

2. Alternatively you can execute the command below.

icacls "D:\inetpub\wwwroot\mysite.com" /grant IIS_IUSRS:F /t
icacls "D:\mysite_data" /grant IIS_IUSRS:F /t

This command give full permissions against D:\inetpub\wwwroot\mysite.com and all sub-directories and files, and against D:\mysite_data and all sub-directories and files to IIS_IUSRS group.

mysite.com user is part of the IIS_IUSRS group.

Operating Systems

How to Restart a Windows Server in a Domain Remotely

August 9, 2023 admin Leave a comment

Problem:

You need to restart a Windows server in a domain remotely because it seems to be stuck and you cannot remotely connect to it via RDP.

Solution:

1. Open cmd.exe and execute 2 commands below.

ping server_name
shutdown /r /m \\server_name /t 0/

2. You may get the error below.

server_name: A system shutdown is in progress.(1115)

3. Download and extract PSTools.

4. Open cmd.exe and execute 3 commands below.

cd C:\Users\admin\Downloads\PSTools
pskill \\server_name winlogon
pskill \\server_name TrustedInstaller

Software Engineering Research

How to Be Creative in Software Engineering Research

July 9, 2023 admin Leave a comment

Motivation:

You plan to do a software engineering research and want to make some minor authentic contributions.

Guidelines:

1. You may present a problem and corresponding existing solution using your own understanding.

A method to do this is to

Read papers and books about a concept (for example backpropagation or distributed transactions), then
Write down the concept and some related terminologies, then
Try explain the concept with examples using your speech, and
Record your presentation, then
Write down your transcript, then
Rephrase your transcript.

2. You may try to replicate an existing result. When doing this you may need to make minor changes due to specific technology or environment conditions. Then you can compare your result with the original result.

For example, you may compare your business workflows with existing business workflows to determine which solution may solve a specific problem faster or more reliable.

In case you do not make any minor changes, the replication process may also inspire you some technical ideas. You may get errors while replicating the result. Try to fix these errors and document your experience.

For example you may get errors when upgrading an existing system from Node.js 12 to Node.js 18, or when upgrading an existing deep learning model code from Python 3.9 to Python 3.11. Try to fix the errors, then document your inputs, errors and solution.

3. The core idea to be creative is to do something that you have not done before. You may use trial and error method but be sure that you have a hard unsolved problem first. Trying to search for partial solutions to a problem will inspire you some ideas which may be the starting point for your minor authentic contributions.

4. Each individual’s creativity will need to be developed over time rather than in accordance with any kind of set formula.

Operating Systems

How to Set File Permissions for WordPress on Ubuntu

June 21, 2023 admin Leave a comment

Motivation:

You have a WordPress instance on Ubuntu Nginx.
You want to ensure that only the Nginx process can access WordPress files.

Procedure:

View current file owner and group:

ls -l /var/html

The root folder should be owned by www-data user. www-data is the user that web servers like Apache and Nginx on Ubuntu use by default for their normal operation.

2. Change file owner and group to www-data if necessary:

sudo chown -R www-data:www-data /var/html

3. Set minimum permissions for folders:

cd /var/html
sudo find . -type d -exec chmod 755 {} \; # directory permissions rwxr-xr-x

4. Set minimum permissions for files:

cd /var/html
sudo find . -type f -exec chmod 644 {} \; # file permissions rw-r--r--

5. Verify the changes:

ls -l /var/html

Web Application Development

How to Back Up and Restore IIS App Pool and Site Settings

June 19, 2023 admin Leave a comment

Motivation:

You want to back up and restore IIS app pool and site settings.

Solution:

1. Open Command Prompt (Admin) and execute commands below to export IIS app pool and site settings to XML files.

%windir%\system32\inetsrv\appcmd list apppool /config /xml > \\192.168.101.140\BCDR\WEBBC02\E\inetpub\apppools.xml
%windir%\system32\inetsrv\appcmd list site /config /xml > \\192.168.101.140\BCDR\WEBBC02\E\inetpub\sites.xml

2. Remove all existing IIS app pools and sites, then execute the command below to import IIS app pool and site settings from XML files.

%windir%\system32\inetsrv\appcmd list apppool /config /xml < \\192.168.101.140\BCDR\WEBBC02\E\inetpub\apppools.xml
%windir%\system32\inetsrv\appcmd list site /config /xml < \\192.168.101.140\BCDR\WEBBC02\E\inetpub\sites.xml

Learning English

Forget vs. Forget About

June 18, 2023 admin Leave a comment

Forget is a general word, forget about is more specific.

“I forgot my keys.“: Person forgot their keys, as in it was left somewhere, and the person doesn’t have it.
“I want to forget about my keys.“: Person would like to “un”know about its keys, or wants to bury the memories of it.
“I forgot that face.“: Person doesn’t remember how someone’s face looked like.
“I forgot about that face.“: Non-direct way of saying one doesn’t remember all the facial features – but not the entire face.

Tech Devices

macOS Tips

June 6, 2023 admin Leave a comment

1. Cut and Paste:

Command+C, then Command+Option+V

2. Show IP address:

ifconfig | grep inet

3. Create a file:

touch filename

3. Take a screenshot

To capture the entire screen, press Command + Shift + 3.
To capture a window, press Command + Shift + 4 + Space.
To capture a portion of the screen, press Command + Shift + 4.

Source: https://support.apple.com/en-us/HT201361

5. Increase Terminal text size

Open Terminal app.
Click Terminal > Settings… > Profiles > Basic.
Click Text.
Locate Font section. Click Change…. button.
Select a new size.
Close Font window.
Close Profiles window.
Click Shell tab beside Terminal.
Select New Window > New Window with Profile – Basic.

6. Prevent your Mac from automatically disabling remote login

Open System Preferences.
Select Energy Saver.
Select Prevent computer from sleeping automatically when the display is off.
Deselect Put hard disks to sleep when possible.
Drag the Turn display off after slider to 3 hours or Never.
Important step: repeat the procedure for Battery tab.

7. Set static IP

Open System Preferences > Wi-Fi.
Click Details button beside a network.
Click TCP/IP item on the left.
Select Using DHCP with Manual Address for Configure IPv4. Do NOT select Manually option. Using DHCP with Manual Address means that you just want to change only IP address. Manually means that you want to set up IP address, Subnet mask and router IP. Choosing Manually may cause Internet access issue if you are connecting your computer to a router with Access Point mode. Please refer to Apple guide for more information.
Enter IP address.
Click OK button.
Restart your machine.

8. View memory using command line

top -l 1 -s 0 | grep PhysMem

9. Keynote: Turn smart dashes on or off

Turning smart dashes on or off doesn’t affect existing hyphens and dashes in your document, only new text that you type.

Choose Pages > Preferences (from the Pages menu at the top of your screen).
Click Auto-Correction at the top of the preferences window.
In the Formatting section, select or deselect the “Use smart quotes and dashes” checkbox.

Source: https://support.apple.com/en-vn/guide/pages/tanad45f9cce/mac

10. Copy data from one MacBook to another using AirDrop

Generally Apple’s native AirDrop is the most optimized and fastest option for peer-to-peer file transfers over Wi-Fi, thanks to its use of both Wi-Fi Direct and Bluetooth LE for setup and high-speed data transfer.

This method is easy to use, but it is unreliable for a folder containing thousands of files and more than 20GB in size.

A. On the Sending and Receiving Mac:

Open Finder.
Click on “AirDrop” in the sidebar (or press Cmd + Shift + R).
Ensure that “Allow me to be discovered by” is set to either “Everyone” or “Contacts Only” (the same applies to the receiving Mac).
Wait for the other Mac to appear in the AirDrop window.

B. On the Sending Mac:

Drag and drop files onto the icon for the receiving Mac.

C. On the Receiving Mac:

A prompt will appear when the sender initiates the transfer:
Click Accept.
Choose to Save to Downloads (default) or a custom folder.

11. Copy data from one MacBook to another using SSH

Folder to copy: /Volumes/Bootcamp/alice
SSH access must be enabled on the destination MacBook (System Settings > General > Sharing > Remote Login).
Destination Mac username: admin
Destination IP address: 192.168.1.45
Destination path: /Users/admin/Documents/

On the source Mac (Terminal):

scp -r "/Volumes/Bootcamp/alice" [email protected]:/Users/admin/Downloads/

12. Copy data from Windows to macOS using SSH

Folder to copy: H:\Archived
SSH access must be enabled on the destination MacBook (System Settings > General > Sharing > Remote Login).
Destination Mac username: admin
Destination IP address: 192.168.1.45
Destination path: /Users/admin/Documents/

On the source Windows (Command Prompt):

scp -r "H:\Archived" [email protected]:/Users/admin/Downloads/

13. Copy data from macOS to Windows using SSH

Folder to copy: /Users/admin/Documents/
SSH access must be enabled on the source MacBook (System Settings > General > Sharing > Remote Login).
Source Mac username: admin
Source IP address: 192.168.1.45
Destination Windows path: H:\Archived

On the source Windows (Command Prompt):

scp -r [email protected]:/Users/admin/Downloads/ "H:\Archived"

14. Give the admin user full permissions against the Downloads folder

Take ownership of the folder
```
sudo chown -R admin ~/Downloads
```
Set correct permissions
```
sudo chmod -R u+rwX ~/Downloads
```
(Optional but recommended) Remove restrictive ACLs (Remove all ACL entries from the folder and its contents)
```
sudo chmod -RN ~/Downloads
```

Operating Systems

How to Fix Firefox No Sound Issue

June 5, 2023 admin Leave a comment

Problem:

Your Firefox suddenly does not play any sounds.

You have tried uninstalling and reinstalling it but the problem still persists.

Quick Solution:

Go to Windows Settings > Sound > Advanced Sound Options .
Make sure Firefox is not muted or set to low volume.

Advanced Solution:

Create a Firefox account and synchronize (make a backup of) your current settings.
Uninstall Firefox using Windows Apps and features.
Go to %APPDATA%\Mozilla and delete Firefox folder.
Open regedit.exe, search for Firefox, and delete all the keys and values that can be found. This process will take some time. Just ignore any errors that may occur when some keys or values cannot be deleted.
Restart your computer.
Download Firefox offline installer.
Install Firefox.
Log in your Firefox account and restore your settings.

Operating Systems

How to Determine all Ports Opened by a Program in Windows

May 24, 2023 admin Leave a comment

Motivation:

You want to ensure that your server is not compromised by a program.

Solution:

1. Open cmd.exe and execute commands below. Note the program file name and one of its ports that you want to investigate further.

netstat -a -b

2. Execute the command below. Note the PID associated with the port that you are interested in.

netstat -ano -p tcp

3. Execute commands below. “1544” is the PID that you are interested in.

netstat -ano -p tcp |find "1544"

4. Open https://mxtoolbox.com/TCPLookup.aspx, and enter [your external IP:port], and click TCP Lookup button to check if a port is open from your server.

5. Go to your Firewall and block the port if it should not be open to the Internet.

Database Management Systems

How to Change SQL Server sa User’s Password

April 7, 2023 admin Leave a comment

Problem:

You are a Windows Administrator and you can log in SQL server instance. However you cannot access databases.
You want to log in the SQL server instance under sa user but you forget the sa user’s password.
You cannot the sa user’s password using SQL Server Management Studio.

Solution:

1. Open cmd.exe and execute commands below. Replace MSSQL$SQLEXPRESS with your SQL service name and localhost\SQLEXPRESS with your SQL instance.

net stop MSSQL$SQLEXPRESS
net start MSSQL$SQLEXPRESS /m"SQLCMD"
sqlcmd -S localhost\SQLEXPRESS

2. Type and press Enter for each line below.

ALTER LOGIN [sa] WITH DEFAULT_DATABASE=[master]
GO
USE [master]
GO
ALTER LOGIN [sa] WITH PASSWORD=N'Password@1234'
GO
exit

3. Open cmd.exe and execute commands below.

net stop MSSQL$SQLEXPRESS
net start MSSQL$SQLEXPRESS

4. Open SQL Server Management Studio and log in the SQL server using the sa account.

Software Development

All posts by admin

How to Set File Permissions for ASP.NET Website on Windows

Problem:

Solution:

How to Restart a Windows Server in a Domain Remotely

Problem:

Solution:

How to Be Creative in Software Engineering Research

Motivation:

Guidelines:

How to Set File Permissions for WordPress on Ubuntu

Motivation:

Procedure:

How to Back Up and Restore IIS App Pool and Site Settings

Motivation:

Solution:

Forget vs. Forget About

How to Fix Firefox No Sound Issue

Problem:

Quick Solution:

Advanced Solution:

How to Determine all Ports Opened by a Program in Windows

Motivation:

Solution:

How to Change SQL Server sa User’s Password

Problem:

Solution:

Software development and software engineering research