C# SPSS SAV file reader and writer library

Demo Spss to json convertor.

This library enables to read and write SPSS data files (.sav) on .net from and to a Stream. The library is UTF-8 safe.

It is available as a nuget package at https://www.nuget.org/packages/SpssReader en https://www.nuget.org/packages/SpssWriter, and can be installed using the package manager or by issueing:

Install-Package SpssReader
Install-Package SpssWriter

It's a fork of SPSS-.NET-Reader by fbiagi (based on spsslib-80132 by elmarj). Since forking there are a lot of bug fixing for utf8 support. Added :

• string valuesLabels
• string missing.
• BigEndian
• Improved spssReader performance by 4000%

The libriary is refactored to a cleancode library

To read a data file:

    using var fileStream = new FileStream("TestFiles/test.sav", FileMode.Open);

    var spssReader = new SpssReader(fileStream);

    var rowReader = spssReader.RowReader;
    foreach (var column in rowReader.Columns)
    {
        Console.WriteLine($"{column.Variable.Name}, {column.Variable.Label}");
        if (column.Variable.ValueLabels != null)
            Console.WriteLine(string.Join(",", column.Variable.ValueLabels.Select(x => $"{x.Key} - {x.Value} ")));
        Console.WriteLine(string.Join(",", column.Variable.MissingValues));
    }
    while (rowReader.ReadRow())
    {
        foreach (var column in rowReader.Columns)
        {
            Console.WriteLine($"{column.Variable.Name}={column.GetValue()}");
            // OR without boxing
            switch (column.ColumnType)
            {
                case ColumnType.String:
                    Console.WriteLine($"{column.Variable.Name}={column.GetString()}");
                    break;
                case ColumnType.Double:
                    Console.WriteLine($"{column.Variable.Name}={column.GetDouble()}");
                    break;
                case ColumnType.Int:
                    Console.WriteLine($"{column.Variable.Name}={column.GetInt()}");
                    break;
                case ColumnType.Date:
                    Console.WriteLine($"{column.Variable.Name}={column.GetDate()}");
                    break;
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }
    }

To write a data file:

// Create Variable list
    var variables = new List<Variable>
    {
        new Variable<string>("var0", 8)
        {
            Label = "label for var0",
            ValueLabels = new Dictionary<string, string>
            {
                ["a"] = "valueLabel for a",
                ["b"] = "valueLabel for b"
            }
        }.UserMissingValues(MissingValueType.OneDiscreteMissingValue, new[] { "-" }),
        new Variable<double>("var2", 7, 3)
        {
            Label = "label for var2",
            ValueLabels = new Dictionary<double, string>
            {
                [15.5] = "valueLabel for 15.5",
                [16] = "valueLabel for 16"
            }
        }.UserMissingValues(new[] { 0d }),
        new Variable<DateTime>("var4", 20)
        {
            Label = "label for var4",
            ValueLabels = new Dictionary<DateTime, string>
            {
                [new DateTime(2020, 1, 2)] = "valueLabel for 2 jan 2020",
                [new DateTime(2020, 1, 1)] = "valueLabel for 1 jan 2020"
            }
        }
    };
    // create data
    var data = new List<object?>
    {
        "string", 15.5, new DateTime(2020, 1, 1),
        null, null, null
    };

    //Write variable and data to a stream
    var ms = new MemoryStream();
    SpssWriter.Write(variables, data, ms);

If you find any bugs or have issues, please open an issue on GitHub.

SAV file format

Binary description of *.sav file format is available here: http://www.gnu.org/software/pspp/pspp-dev/html_node/System-File-Format.html.