DEV Community: Stanislav Berkov

Snipping tool compressed mp4

Stanislav Berkov — Tue, 20 Jan 2026 20:37:57 +0000

Windows Snipping Tool can record screen and product mp4 files, but these files are uncompressed. You need to run external tool to compress them. You can do it with ffmpeg + add "Compress MP4" Windows Explorer context menu item.

Install ffmpeg

Run winget install Gyan.FFmpeg command. It shall install ffmpeg

Run as administrator script

#Requires -RunAsAdministrator

$basePath = "Registry::HKEY_CLASSES_ROOT\SystemFileAssociations\.mp4\shell\CompressMP4"

New-Item -Path $basePath -Force | Out-Null
Set-ItemProperty -Path $basePath -Name "(Default)" -Value "Compress MP4"

$command = 'powershell -NoProfile -Command "$f = ''%1''; $out = $f -replace ''\.mp4$'', ''_compressed.mp4''; ffmpeg -i $f -c:v libx264 -crf 28 -preset medium -c:a aac -b:a 128k $out; pause"'

New-Item -Path "$basePath\command" -Force | Out-Null
Set-ItemProperty -Path "$basePath\command" -Name "(Default)" -Value $command

Write-Host "Added Compress MP4 context menu" -ForegroundColor Green

It shall create context menu item.

Disable antivirus real-time monitoring with PowerShell

Stanislav Berkov — Fri, 31 Oct 2025 18:01:45 +0000

This is analog of TURBO button of modern days.

Create file .\no-av-monitoring.ps1 with content

# Get the ID and security principal of the current user account
$myWindowsID = [System.Security.Principal.WindowsIdentity]::GetCurrent()
$myWindowsPrincipal = new-object System.Security.Principal.WindowsPrincipal($myWindowsID)

# Get the security principal for the Administrator role
$adminRole = [System.Security.Principal.WindowsBuiltInRole]::Administrator

# Check to see if we are currently running "as Administrator"
if ($myWindowsPrincipal.IsInRole($adminRole)) {
    # We are running "as Administrator" - so change the title and background color to indicate this
    $Host.UI.RawUI.WindowTitle = $myInvocation.MyCommand.Definition + "(Elevated)"
    # $Host.UI.RawUI.BackgroundColor = "DarkBlue"
    clear-host
}
else {
    # We are not running "as Administrator" - so relaunch as administrator

    # Create a new process object that starts PowerShell
    $newProcess = new-object System.Diagnostics.ProcessStartInfo "PowerShell";

    # Specify the current script path and name as a parameter
    $newProcess.Arguments = $myInvocation.MyCommand.Definition;

    # Indicate that the process should be elevated
    $newProcess.Verb = "runas";

    # Start the new process
    [System.Diagnostics.Process]::Start($newProcess);

    # Exit from the current, unelevated, process
    exit
}

Set-MpPreference -DisableRealtimeMonitoring $true

start-sleep -seconds 2

VS Code Vim save when exit INSERT mode

Stanislav Berkov — Thu, 28 Aug 2025 21:22:04 +0000

In VS Code settings simple add

"vim.insertModeKeyBindings": [
    {
        "before": ["<C-[>"],
        "after": ["<C-[>"],
        "commands": ["workbench.action.files.save"]
    }
]

Dropping old Cassandra keyspaces

Stanislav Berkov — Thu, 05 Jun 2025 20:39:56 +0000

I have Cassandra instance that is use for running end-to-end tests by GitLab runner after each commit. Each run creates temporary keyspace. Usually test performs cleanup but sometimes job can fail. As a result, dangling Cassandra keyspace appears. To solve this problem, I wrote a script that deletes keyspaces that are 1day+ old. Cron runs this script daily. While writing this script I encountered several pitfalls.

How to get age of keyspace?
I did not find column that reflects time of KS creation. But there is system_schema.keyspaces table with all keyspaces.
I decided to use writetime function.

SELECT writetime(durable_writes) as time, keyspace_name FROM system_schema.keyspaces;

This works ok besides we need to trim header and footer. This can be done with command

query_result=$(cqlsh -e "SELECT writetime(durable_writes) as time, keyspace_name FROM system_schema.keyspaces;" --no-color 2>&1)

Full script

#!/bin/bash

# Default values
DRY_RUN=false
KEYSPACE_PREFIX="cqgm_"
EXPIRATION_TIME=$((2*24*60*60))  # 2 days in seconds

# Process command-line arguments
while [[ $# -gt 0 ]]; do
    case "$1" in
        --dry-run)
            DRY_RUN=true
            shift
            ;;
        --prefix)
            if [[ -z "$2" || "$2" == --* ]]; then
                echo "Error: --prefix requires a value"
                exit 1
            fi
            KEYSPACE_PREFIX="$2"
            shift 2
            ;;
        --expiration-time)
            if [[ -z "$2" || "$2" == --* ]]; then
                echo "Error: --expiration-time requires a value"
                exit 1
            fi
            if ! [[ "$2" =~ ^[0-9]+$ ]]; then
                echo "Error: --expiration-time must be a positive integer (seconds)"
                exit 1
            fi
            EXPIRATION_TIME="$2"
            shift 2
            ;;
        -h|--help)
            echo "Usage: $0 [OPTIONS]"
            echo "Options:"
            echo "  --dry-run              Show what would be done without actually dropping keyspaces"
            echo "  --prefix PREFIX        Specify keyspace prefix to match (default: cqgm_)"
            echo "  --expiration-time SEC  Specify expiration time in seconds (default: 172800 = 2 days)"
            echo "  -h, --help             Show this help message"
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            echo "Use -h or --help for usage information"
            exit 1
            ;;
    esac
done

# Get current timestamp in seconds
current_timestamp=$(date +%s)

# Calculate cutoff timestamp using the expiration time
cutoff_timestamp=$((current_timestamp - EXPIRATION_TIME))

# Calculate human-readable time period for display
days=$((EXPIRATION_TIME / 86400))
hours=$(( (EXPIRATION_TIME % 86400) / 3600 ))
minutes=$(( (EXPIRATION_TIME % 3600) / 60 ))
seconds=$((EXPIRATION_TIME % 60))
time_period=""
[[ $days -gt 0 ]] && time_period+="$days days "
[[ $hours -gt 0 ]] && time_period+="$hours hours "
[[ $minutes -gt 0 ]] && time_period+="$minutes minutes "
[[ $seconds -gt 0 ]] && time_period+="$seconds seconds"
time_period=${time_period:-"0 seconds"}

if [ "$DRY_RUN" = true ]; then
    echo "Running in DRY-RUN mode - No keyspaces will be dropped"
else
    echo "Running in NORMAL mode - Keyspaces will be dropped"
fi
echo "Settings:"
echo "  Keyspace prefix: '$KEYSPACE_PREFIX'"
echo "  Expiration time: $EXPIRATION_TIME seconds ($time_period)"

echo "Checking for keyspaces with prefix '$KEYSPACE_PREFIX' that are older than $time_period..."

query_result=$(cqlsh -e "SELECT writetime(durable_writes) as time, keyspace_name FROM system_schema.keyspaces;" --no-color 2>&1)

if [[ $? -ne 0 ]]; then
    echo "Error executing CQL query: $query_result"
    exit 1
fi

# Process the query results
echo "$query_result" | tail -n +4 | head -n -2 | while read -r line; do
    [ -z "$line" ] && continue

    # Parse the line to extract timestamp and keyspace name
    time_str=$(echo "$line" | awk -F'|' '{print $1}' | tr -d ' ')
    keyspace_str=$(echo "$line" | awk -F'|' '{print $2}' | tr -d ' ')

    # Skip if either field is empty
    [ -z "$time_str" ] || [ -z "$keyspace_str" ] && continue

    # Check if keyspace starts with the specified prefix
    if [[ "$keyspace_str" == ${KEYSPACE_PREFIX}* ]]; then
        # Convert timestamp from microseconds to seconds
        timestamp_seconds=$((time_str / 1000000))

        # Format the date for display
        created_date=$(date -d @$timestamp_seconds "+%Y-%m-%d %H:%M:%S")

        # Compare with cutoff timestamp
        if [ "$timestamp_seconds" -lt "$cutoff_timestamp" ]; then
            if [ "$DRY_RUN" = true ]; then
                echo "[DRY-RUN] Would drop keyspace $keyspace_str (created $created_date)"
            else
                echo "Dropping keyspace $keyspace_str (created $created_date)"
                drop_result=$(cqlsh -e "DROP KEYSPACE $keyspace_str;" 2>&1)
                if [[ $? -ne 0 ]]; then
                    echo "Error dropping keyspace $keyspace_str: $drop_result"
                fi
            fi
        else
            echo "Keyspace $keyspace_str is newer than $time_period (created $created_date)"
        fi
    fi
done

if [ "$DRY_RUN" = true ]; then
    echo "Dry run completed. No keyspaces were dropped."
else
    echo "Done."
fi

Protobuf fake data generator

Stanislav Berkov — Thu, 30 Jan 2025 06:02:50 +0000

Let's assume you have protobuf proto files, generated C# message classes for them, and you want to generate fake data for demo purposes. You can use Google.Protobuf.Reflection for it as follows:

using System;
using System.Collections.Generic;
using System.Linq;
using Google.Protobuf;
using Google.Protobuf.Reflection;
using Google.Protobuf.Collections;
using Google.Protobuf.WellKnownTypes;
using System.Collections;

public class ProtobufFaker {
    private readonly Random _random;
    private readonly int _maxCollectionSize;
    private readonly int _stringMaxLength;

    public ProtobufFaker(int? seed = null, int maxCollectionSize = 5, int stringMaxLength = 20) {
        _random = seed.HasValue ? new Random(seed.Value) : new Random();
        _maxCollectionSize = maxCollectionSize;
        _stringMaxLength = stringMaxLength;
    }

    public T Generate<T>() where T : IMessage, new() {
        var message = new T();
        PopulateMessage(message);
        return message;
    }

    public void PopulateMessage(IMessage message) {
        var descriptor = message.Descriptor;
        foreach (var fieldDescriptor in descriptor.Fields.InDeclarationOrder()) {
            if (fieldDescriptor.IsRepeated) {
                var list = (IList)fieldDescriptor.Accessor.GetValue(message);
                var count = _random.Next(1, _maxCollectionSize + 1);
                for (int i = 0; i < count; i++) {
                    var value = GenerateSingleValue(fieldDescriptor);
                    if (value != null) {
                        list.Add(value);
                    }
                }
            }
            else {
                var value = GenerateFieldValue(fieldDescriptor);
                if (value != null) {
                    fieldDescriptor.Accessor.SetValue(message, value);
                }
            }
        }
    }

    private object? GenerateFieldValue(FieldDescriptor field) {
        if (field.IsMap) {
            return GenerateMapField(field);
        }

        // Handle oneof fields
        if (field.ContainingOneof != null) {
            // Randomly decide whether to set this oneof field
            if (_random.Next(2) == 0) {
                return null;
            }
        }

        return GenerateSingleValue(field);
    }

    private object? GenerateSingleValue(FieldDescriptor field) {
        if (field.FieldType == FieldType.Message && field.MessageType.FullName == "google.protobuf.Timestamp") {
            return GenerateTimestamp();
        }

        return field.FieldType switch {
            FieldType.Double => _random.NextDouble() * 1000,
            FieldType.Float => (float)(_random.NextDouble() * 1000),
            FieldType.Int64 or FieldType.SInt64 or FieldType.SFixed64 => (long)_random.Next(1, 1000),
            FieldType.UInt64 or FieldType.Fixed64 => (ulong)_random.Next(1, 1000),
            FieldType.Int32 or FieldType.SInt32 or FieldType.SFixed32 => _random.Next(1, 1000),
            FieldType.Fixed32 or FieldType.UInt32 => (uint)_random.Next(1, 1000),
            FieldType.Bool => _random.Next(2) == 1,
            FieldType.String => GenerateRandomString(),
            FieldType.Bytes => GenerateRandomBytes(),
            FieldType.Enum => GenerateEnumValue(field.EnumType),
            FieldType.Message => GenerateNestedMessage(field.MessageType),
            _ => null,
        };
    }

    private object? GenerateMapField(FieldDescriptor field) {
        var count = _random.Next(1, _maxCollectionSize + 1);
        var mapField = field.Accessor.GetValue((IMessage?)Activator.CreateInstance(field.ContainingType.ClrType));
        var mapDescriptor = field.MessageType;
        var keyDescriptor = mapDescriptor.FindFieldByNumber(1); // Key is always field 1
        var valueDescriptor = mapDescriptor.FindFieldByNumber(2); // Value is always field 2

        var addMethod = mapField.GetType().GetMethod("Add");
        if (addMethod == null) { return null; }

        for (int i = 0; i < count; i++) {
            var key = GenerateSingleValue(keyDescriptor);
            var value = GenerateSingleValue(valueDescriptor);

            if (key != null && value != null) {
                addMethod.Invoke(mapField, [key, value]);
            }
        }

        return mapField;
    }

    private IMessage? GenerateNestedMessage(MessageDescriptor messageDescriptor) {
        var message = (IMessage?)Activator.CreateInstance(messageDescriptor.ClrType);
        if (message == null) { return null; }
        PopulateMessage(message);
        return message;
    }

    private object GenerateEnumValue(EnumDescriptor enumDescriptor) {
        var values = enumDescriptor.Values;
        var randomIndex = _random.Next(values.Count);
        return values[randomIndex].Number;
    }

    private Timestamp GenerateTimestamp() {
        var now = DateTime.UtcNow;
        var daysOffset = _random.Next(-365 * 2, 365 * 2); // ±2 years from now
        var hoursOffset = _random.Next(-24, 24);
        var minutesOffset = _random.Next(-60, 60);

        var randomTime = now
            .AddDays(daysOffset)
            .AddHours(hoursOffset)
            .AddMinutes(minutesOffset);

        return Timestamp.FromDateTime(randomTime);
    }

    private string GenerateRandomString() {
        const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        var length = _random.Next(1, _stringMaxLength + 1);
        return new string(Enumerable.Repeat(chars, length)
            .Select(s => s[_random.Next(s.Length)]).ToArray());
    }

    private ByteString GenerateRandomBytes() {
        var length = _random.Next(1, _stringMaxLength + 1);
        var bytes = new byte[length];
        _random.NextBytes(bytes);
        return ByteString.CopyFrom(bytes);
    }
}

// Example usage:
/*
public class Program
{
    public static void Main()
    {
        var faker = new ProtobufFaker();

        // Generate fake data for any protobuf message
        var message = faker.Generate<YourProtobufMessage>();

        // The faker will properly handle:
        // - All protobuf field types
        // - Repeated fields
        // - Map fields
        // - Oneof fields
        // - Nested messages
        // - Enums
        // - Optional fields

        Console.WriteLine(message.ToString());
    }
}
*/

https://gist.github.com/stasberkov/2d12925ea1d30c712fe9240bd5c7ea8b

Docker in Windows via WSL2, Ubuntu, docker

Stanislav Berkov — Sun, 29 Dec 2024 21:38:40 +0000

If you cannot use Docker Desktop you still can use docker in Windows via Linux and WSL2.

How to:

install WSL2,
enable mirrored networking mode for WLS2 (fix no connectivity when using CiscoVPN),
install Ubuntu 22.04,
install docker-ce on Ubuntu,
allow docker remote connection,
install Docker CLI in windows,
specify DOCKER_HOST.

As a result, you get docker command working in WSL2 and in Windows.

Mirrored networking mode for WSL2

Update config https://learn.microsoft.com/en-us/windows/wsl/wsl-config#configuration-settings-for-wslconfig:~:text=Windows%20to%20Linux.-,networkingMode,-%C2%B9%C2%B2
set networkingMode=mirrored

Install Docker

Follow instructions at https://docs.docker.com/engine/install/ubuntu/

Allow running `docker` command w/o root

sudo groupadd docker
sudo usermod -aG docker $USER
<reboot> or newgrp docker

Allow docker remote connections

Edit the file /etc/systemd/system/docker.service.d/override.conf by calling the command

systemctl edit docker

Change content to:

[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H fd:// --containerd=/run/containerd/containerd.sock

Reload systemd and restart docker

systemctl daemon-reload
systemctl restart docker

Check that port is being listen

netstat -lntp | grep 2375

If not, check the docker logs

journalctl -xeu docker.service

In Windows install docker cli

winget install Docker.DockerCLI

Set environment variable

$env:DOCKER_HOST="tcp://localhost:2375"

You might get `docker-credential-wincred` not found error

Similar issue is discussed here https://github.com/docker/docker-credential-helpers/issues/24

Edit ~/.docker/config.json file to remove credsStore param.

Capybara Math Privacy Policy

Stanislav Berkov — Tue, 14 May 2024 03:05:50 +0000

Effective Date: 2024-05-13

Introduction Stanislav Berkov is committed to protecting the privacy of children who use our Capybara Math (“Application”). This Privacy Policy explains our information practices for our Application, which is designed for children under the age of 13.
Information Collection and Use Our Application does not collect any personal information from its users, including children under the age of 13.
Parental Consent Although we do not collect personal information, we still provide information about our practices for parents and guardians to review.
Log Data We do not collect information that is automatically generated by the use of our Application, such as IP addresses or device identifiers.
Cookies Our Application does not use cookies or similar tracking technologies.
Third-Party Access Since our Application does not collect personal information, we do not share any user data with third parties.
Data Security We are committed to protecting the security of our users’ information. As we do not collect personal information, we focus on preventing unauthorized access to our Application.
Changes to This Privacy Policy We may update our Privacy Policy from time to time. Parents will be notified of any significant changes to our practices regarding children’s data.
Contact Us If you have any questions about our privacy practices or this Privacy Policy, please contact us at https://twitter.com/StasBerkov.

Denver Dev Day snake puzzle solver

Stanislav Berkov — Sun, 17 Dec 2023 18:47:35 +0000

At https://www.meetup.com/DenverDevDay/ 2023 Fall I get the following puzzle.

When disassembled it looks this way

Quite hard puzzle I would say. I decided to write a C# program to solve it.

const int dim = 3;
int[] snake = { 3, 3, 3, 3, 2, 2, 2, 3, 3, 2, 2, 3, 2, 3, 2, 2, 3 };

bool[,,] used = new bool[dim, dim, dim];

Stack<Point> path = new();
used[0, 0, 0] = true;

if (DFS((0, 0, 0), 0, (0, 0, 0))) {
    foreach (var m in path.Reverse()) {
        Console.WriteLine(m);
    }
};

bool DFS(Point p, int idx, Point m) {
    if (idx >= snake.Length) {
        return false;
    }

    if (p == (dim - 1, dim - 1, dim - 1) && idx == snake.Length - 1) {
        Console.WriteLine("done!");
        return true;
    }

    foreach (var move in Point.Moves) {
        if (move == m) { continue; }
        var len = (snake[idx] - 1);
        var nextLen1Or2 = p + (move * len);
        var nextLen1 = p + move;
        if (!nextLen1Or2.InCube(dim)) { continue; }
        if (used[nextLen1Or2.X, nextLen1Or2.Y, nextLen1Or2.Z]) { continue; }
        if (used[nextLen1.X, nextLen1.Y, nextLen1.Z]) { continue; }
        path.Push(move);
        used[nextLen1Or2.X, nextLen1Or2.Y, nextLen1Or2.Z] = true;
        used[nextLen1.X, nextLen1.Y, nextLen1.Z] = true;
        if (DFS(nextLen1Or2, idx + 1, move)) {
            return true;
        }
        path.Pop();
        used[nextLen1Or2.X, nextLen1Or2.Y, nextLen1Or2.Z] = false;
        used[nextLen1.X, nextLen1.Y, nextLen1.Z] = false;
    }

    return false;
}

public record struct Point(int X, int Y, int Z) {
    public static readonly Point[] Moves = { (-1, 0, 0), (0, -1, 0), (0, 0, -1), (1, 0, 0), (0, 1, 0), (0, 0, 1) };
    public static Point operator +(Point a, Point b) => new(a.X + b.X, a.Y + b.Y, a.Z + b.Z);
    public static Point operator *(Point a, int f) => new(a.X * f, a.Y * f, a.Z * f);
    public static implicit operator Point((int X, int Y, int Z) p) => new(p.X, p.Y, p.Z);
    public readonly bool InCube(int size) => X >= 0 && X < size && Y >= 0 && Y < size && Z >= 0 && Z < size;
}

So the solution is:

Point { X = 1, Y = 0, Z = 0 }
Point { X = 0, Y = 1, Z = 0 }
Point { X = -1, Y = 0, Z = 0 }
Point { X = 0, Y = 0, Z = 1 }
Point { X = 1, Y = 0, Z = 0 }
Point { X = 0, Y = 0, Z = -1 }
Point { X = 1, Y = 0, Z = 0 }
Point { X = 0, Y = -1, Z = 0 }
Point { X = -1, Y = 0, Z = 0 }
Point { X = 0, Y = 0, Z = 1 }
Point { X = 0, Y = 1, Z = 0 }
Point { X = 0, Y = 0, Z = -1 }
Point { X = 1, Y = 0, Z = 0 }
Point { X = 0, Y = 0, Z = 1 }
Point { X = 1, Y = 0, Z = 0 }
Point { X = 0, Y = 1, Z = 0 }

Magic square problem and solver in C#

Stanislav Berkov — Wed, 13 Dec 2023 17:37:00 +0000

My 2nd grade daughter get the following math problem:

I tried to solve it for couple hours but no luck. Then I wrote C# program that employed DFS approach

using System.Diagnostics;

int d = 4;
int magicNumber = 34;

bool[] taken = new bool[d * d + 1];
taken[0] = true;

int[,] state = {
    {15, 0, 0, 0},
    {0, 0, 9, 0},
    {0, 0, 0, 13},
    {0, 11, 0, 0}
};

FillTaken();

var sw = new Stopwatch();
sw.Start();

Dfs((0, 0));

sw.Stop();
Console.WriteLine("Exec time: " + sw.ElapsedMilliseconds + "ms");

void FillTaken() {
    for (int i = 0; i < d; i++) {
        for (int j = 0; j < d; j++) {
            if (state[i, j] != 0) {
                taken[state[i, j]] = true;
            }
        }
    }
}

bool CheckRow(int r) {
    int sum = 0;
    for (int i = 0; i < d; i++) {
        sum += state[r, i];
        if (state[r, i] == 0) {
            return true;
        }
    }

    return sum == magicNumber;
}

bool CheckCol(int c) {
    int sum = 0;
    for (int i = 0; i < d; i++) {
        sum += state[i, c];
        if (state[i, c] == 0) {
            return true;
        }
    }

    return sum == magicNumber;
}

bool OnDiagonal(Point p) {
    if (p.Row == p.Col || p.Row + p.Col == d - 1) {
        return true;
    }
    return false;
}

bool CheckDiag(Point p) {
    if (!OnDiagonal(p)) {
        return true;
    }

    bool hasZero1 = false;
    int sum = 0;
    for (int i = 0; i < d; i++) {
        sum += state[i, i];
        if (state[i, i] == 0) {
            hasZero1 = true;
        }
    }

    if (!hasZero1 && sum != magicNumber) {
        return false;
    }

    bool hasZero2 = false;
    sum = 0;
    for (int i = 0; i < d; i++) {
        var c = d - i - 1;
        sum += state[i, c];
        if (state[i, c] == 0) {
            hasZero2 = true;
        }
    }

    if (hasZero2) {
        return true;
    }

    return sum == magicNumber;
}

void PrintState() {
    for (int i = 0; i < d; i++) {
        for (int j = 0; j < d; j++) {
            Console.Write(state[i, j] + " ");
        }
        Console.WriteLine();
    }
}

bool Dfs(Point p) {
    if (taken.All(x => x)) {
        Console.WriteLine("done");
        PrintState();
        return true;
    }

    foreach (var move in Point.Moves) {
        var next = p + move;
        if (!next.InGrid(d, d)) {
            continue;
        }

        if (state[next.Row, next.Col] != 0) {
            continue;
        }

        for (int i = 1; i <= 16; i++) {
            if (taken[i]) {
                continue;
            }
            state[next.Row, next.Col] = i;
            taken[i] = true;
            if (CheckCol(next.Col) && CheckRow(next.Row) && CheckDiag(next)) {
                if (Dfs(next)) {
                    return true;
                }
            }
            state[next.Row, next.Col] = 0;
            taken[i] = false;
        }
    }

    return false;
}

public record struct Point(int Row, int Col) {
    public static readonly Point[] Moves = { (-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (-1, 1), (0, 1), (1, 1) };
    public static Point operator +(Point a, Point b) => new(a.Row + b.Row, a.Col + b.Col);
    public static implicit operator Point((int Row, int Col) p) => new(p.Row, p.Col);
    public readonly bool InGrid(int rows, int cols) => Row >= 0 && Row < rows && Col >= 0 && Col < cols;
}

Result

done
15 6 12 1
2 7 9 16
3 10 8 13
14 11 5 4
Exec time: 2108ms

Quite long time for i7 12700H. Are there any better ways to solve it, especially that 2nd grader can use?

Sony TV bluetooth remote keeps disconnecting

Stanislav Berkov — Sun, 10 Dec 2023 23:55:25 +0000

Noone knows why this is happening but one suggests solution: Home -> Settings -> Network and Internet -> Home network setup -> IP control -> Simple IP control -> Enable [Default: Disable]

from: https://www.reddit.com/r/sony/comments/121hbgw/remote_controls_bluetooth_keeps_disconnecting/

node-fetch request having custom certificate

Stanislav Berkov — Fri, 01 Dec 2023 06:26:20 +0000

UPDATE 2/24/2025
As of Nodejs v23.8 you can use system certificates, see
https://nodejs.org/en/blog/release/v23.8.0#support-for-using-system-ca-certificates-store-on-macos-and-windows

UPDATE 3/27/2025
Insecure solution: to ignore certificate call

process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;

While developing you have to deal with internal servers that use enterprise SSL certificate. Nodejs has its own certificate storage. Thereby you need to provide certificates explicitly.

const fetch = require("node-fetch").default;
const https = require("https");
const fs = require("fs");

const ca = fs.readFileSync("./mozilla-ca-plus-custom.pem").toString();
const agent = new https.Agent({ ca });

async function main() {
    const res = await fetch("https://server.local/master/api2/v1/UserPages", {
        "headers": {
            "accept": "application/json, text/plain, */*",
            "accept-language": "en-US,en;q=0.9,ru;q=0.8",
            "authorization": "Bearer 1eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ3cGZlX3VzZXJfaWQiOiIzZTQwNjZkMi04Mjg2LTQyNzktOWFjNC04YzNlNTNhMjNjMjYiLCJ3cGZlX2xvZ2luIjoic2JlcmtvdiIsImh0dHA6Ly9zY2hlbWFzLm1pY3Jvc29mdC5jb20vd3MvMjAwOC8wNi9pZGVudGl0eS9jbGFpbXMvcm9sZSI6WyJNYXN0ZXJBZG1pbiIsIkNvbnRlbnRFZGl0b3IiLCJUcmFuc2xhdG9yIiwiTW9uaXRvciJdLCJzdWIiOiI0YTBiZGQyMC01YzJkLTI1NGUtYTE2ZC03YjY1MDVlZjI1NTgiLCJuYmYiOjE3MDE0MDk3NjgsImV4cCI6MTczMjk0NTc2OCwiaXNzIjoiV3BmZVNlcnZlciIsImF1ZCI6IldwZmVTZXJ2ZXIgQ2xpZW50cyJ9.k_aaDTeJUyxYv--KBVJYZCBSAHiG_eGHACz2dqCvr5w",
            "content-type": "application/json",
            "sec-ch-ua": "\"Microsoft Edge\";v=\"119\", \"Chromium\";v=\"119\", \"Not?A_Brand\";v=\"24\"",
            "sec-ch-ua-mobile": "?0",
            "sec-ch-ua-platform": "\"Windows\"",
            "sec-fetch-dest": "empty",
            "sec-fetch-mode": "cors",
            "sec-fetch-site": "same-origin",
        },
        "body": "{}"
        "method": "PUT",
        agent
    });

    const text = await res.text();
    console.log(text);
}

main();

Measure TS script performance

Stanislav Berkov — Wed, 22 Nov 2023 17:50:06 +0000

There are websites like https://jsbench.me/ but for JS. You need to compile code fist. There is an alternative tool for it: typescript playground.

https://www.typescriptlang.org/play

It even supports VIM edit mode (check in plugins).
It looks like this

And it also generates a sharable link for your playground e.g. https://www.typescriptlang.org/play?ssl=10&ssc=1&pln=10&pc=2#code/GYVwdgxgLglg9mABAcwKZQCKojAtgQwBsAFQ-CVAZwAoA3IkVALkTBFwCNUAnAGkVQAHSjEIIWbTj34EAHlhwESZCpUQBeRAEYADAEoJ7Lt0QBvAFCIriQukTBu5WAgwxkMKGs06A3Jeu2UIi4IISwgoQwPBraftaIAO4AFqKoiNQAsvhQSQB0+Bw0WTm53HDgACZ0DGkAVMGh4ZE8eogA9A1hMBFRJgC0iPSEjK0AfALCogiIAGQz-vFW1HIKeESk5FQammyEhIgAPgfB+PLYa8qbagMOTvBgru6eiOP6rRaL1iFdPdG1mro4p97I5oPdHh5KABqKFAqwAXwWiG46BA3CQtzBLjckL8iPMEAQlCCsAgAGsAMowABeaQB7UQAGYAEx+QlgYmICDkJJ01ioBKILKCAA8kmM-HFPFG1D0fkEPGAcG4BEgqFyBG4ZOoACJifhuFA+pqyTq5eYlSZqIFEDAYr5bYgRdoAPo6d1u90+W0w95ImDAdLciC83JJfA0UmUmmoPR+4FcolBIYxYOhtBQahRqm0vRI+ECQiUNIfYHszkpzQZ1ZKDaqLMwck51D8ZmoPpaZn8TvmhNp9XFzPZmP8Ia96yIxEK7iW1UUDUG7U61BgCrGxdmtlEuC2XJiZDUaez-BqjWoCNo1C6hIeJJ9fs6-h6qAGo0mx+IZer9das3m8xHsqc7qiaur6oaP6mualrpDadreN6drOlono6KhiG+mYSLlsmRAxNW5y1ioVANk2I6IG2HZdtozLmlOipASe86gV+a7vua5Y7uq+6HgxKpMSB56UJeupgHA948qgH7Pq+kHSSubEbnGPhAA