Read zero-terminated text

Intermediate · C#. The empty brackets on char mean a terminated string, not a general array that consumes all remaining bytes.

Run this example

Prerequisites: the repository's .NET 10 SDK and a checkout of this source. Run from the repository root:

dotnet run --project docs/examples/CStructSharp.Docs.Examples.csproj -c Release -- terminated-text

The runner checks 41 42 00 reads AB and writes back unchanged. Success includes PASS terminated-text.

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Complete program

The layout, options, input bytes, helper methods, and required types are all included. To adapt it outside the repository, create a .NET 10 console project, add CStructSharp, and replace Program.cs with this complete file. These examples follow the source version; use a matching package when testing a release.

Download the complete C# source.

// Generated from executable documentation examples. Edit the source region, then regenerate.
using System;
using System.IO;
using System.IO.Pipelines;
using System.Linq;
using System.Buffers;
using System.Collections.Generic;
using System.Dynamic;
using System.Globalization;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
using CStructSharp;
using CStructSharp.Codecs;
using CStructSharp.Diagnostics;
using CStructSharp.Introspection;
using CStructSharp.Values;

internal static partial class Program
{
    public static void Main()
    {
        TerminatedText();
        Console.WriteLine("PASS terminated-text");
    }

    private static void TerminatedText()
    {
        var layout = new CStruct("struct label { char text[]; };");
        byte[] bytes = [0x41, 0x42, 0];
        StructValue label = layout.Parse(bytes.AsSpan(), "label");
        Equal("AB", label.Get<string>("text"));
        SequenceEqual(bytes, layout.Serialize("label", label));
    }

    private static void Equal<T>(T expected, T actual)
    {
        if (!EqualityComparer<T>.Default.Equals(expected, actual))
        {
            throw new InvalidOperationException($"Expected '{expected}', received '{actual}'.");
        }
    }

    private static void SequenceEqual(byte[] expected, byte[] actual)
    {
        if (!expected.AsSpan().SequenceEqual(actual))
        {
            throw new InvalidOperationException(
                $"Expected {Convert.ToHexString(expected)}, received {Convert.ToHexString(actual)}.");
        }
    }
}

Try it and diagnose mistakes

Remove the final zero byte.

Answer: Reading fails because the terminator is missing. Restore it; do not assume the end of input is a terminator. The program contains assertions for its original inputs. When changing an input intentionally, update the expected assertion too; an unchanged assertion is not evidence that the new value is wrong.

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