beobank.cs

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;
using iText.Kernel.Pdf.Canvas.Parser.Listener;

using Net.Code.Csv;

using System.Globalization;
using System.Text.RegularExpressions;

var folder = args[0];
var file = args[1];
var cultureInfo = CultureInfo.GetCultureInfo("nl-BE");

WriteCsv.ToFile(ExtractTransactions(folder, cultureInfo),
    Path.Combine(folder, file), delimiter: ';', hasHeaders: true, cultureInfo: cultureInfo
    );

static IEnumerable<Transaction> ExtractTransactions(string folder, CultureInfo cultureInfo)
    => from file in Directory.GetFiles(folder, "*.pdf")
       from line in ExtractLines(file)
       let tx = Transaction.Parse(line, cultureInfo)
       where tx != null
       select tx.Value;

static IEnumerable<string> ExtractLines(string file)
{
    using var pdfReader = new PdfReader(file);
    using var pdfDoc = new PdfDocument(pdfReader);
    for (int page = 1; page <= pdfDoc.GetNumberOfPages(); page++)
    {
        var strategy = new SimpleTextExtractionStrategy();
        var pageContent = PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(page), strategy);
        using var stringReader = new StringReader(pageContent);
        while (stringReader.Peek() >= 0)
        {
            yield return stringReader.ReadLine()!;
        }
    }
}

readonly record struct Transaction([CsvFormat("yyyy-MM-dd")]DateTime Datum, string Omschrijving, decimal Bedrag)
{
    private static readonly Regex regex = new (@"(?<date>\d\d/\d\d/\d\d\d\d) (?<description>.*) (?<amount>-?[.\d]+,\d{2})$");
    public static Transaction? Parse(string s, CultureInfo cultureInfo)
    {
        var m = regex.Match(s);
        return m.Success
            ? new Transaction(
                DateTime.ParseExact(m.Groups["date"].Value, "dd/MM/yyyy", cultureInfo, DateTimeStyles.None),
                m.Groups["description"].Value,
                decimal.Parse(m.Groups["amount"].Value, cultureInfo)
            )
            : null;
    }
}

beobank.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="itext7" Version="7.2.1" />
    <PackageReference Include="Net.Code.Csv" Version="5.0.0-preview.1" />
  </ItemGroup>

</Project>

parses all pdf files in a folder, extracts lines of the form [dd/MM/yyyy] [description] [amount]