CSVFile 3.1.4

CSVFile

This library is a series of unit tested, thoroughly commented CSV parsing functions which I have developed off and on since 2006. Extremely small and easy to implement; includes unit tests for the majority of odd CSV edge cases. Library supports different delimiters, qualifiers, and embedded newlines. Can read and write from data tables.

Why use CSVFile?

A few reasons:

• Compatible with DotNet Framework / C# 2.0 and later. Makes it easy to integrate this library into extremely old legacy projects.
• Between 16-32 kilobytes in size, depending on framework.
• No dependencies.
• Handles all the horrible edge cases from poorly written CSV generating software: custom delimiters, embedded newlines, and doubled-up text qualifiers.
• Reads via streams, optionally using asynchronous I/O. You can parse CSV files larger than you can hold in memory without thrashing.
• Ability to pipe data tables directly into SQL Server using Table Parameter Inserts
• Fastest with direct string parsing or async I/O, but good enough performance when reading from MemoryStreams

CSV edge cases

This library was designed to handle edge cases I experienced when working with partner files.

Tutorial

Want to get started? Here are a few walkthroughs.

Custom CSV Settings

Do you have files that use the pipe symbol as a delimiter, or does your application need double quotes around all fields? No problem!

var settings = new CSVSettings()
{
    FieldDelimiter = '|',
    TextQualifier = '\'',
    ForceQualifiers = true
};
s = array.ToCSVString(settings);

Streaming asynchronous CSV

The latest asynchronous I/O frameworks allow you to stream CSV data off disk without blocking. Here's how to use the asynchronous I/O features of Dot Net 5.0:

using (var cr = CSVReader.FromFile(filename, settings)) {
    await foreach (string[] line in cr) {
        // Do whatever you want with this one line - the buffer will
        // only hold a small amount of memory at once, so you can 
        // iterate at your own pace!
    }
}

Streaming CSV without async

Don't worry if your project isn't yet able to use asynchronous foreach loops. You can still use the existing reader logic:

using (CSVReader cr = new CSVReader(sr, settings)) {
    foreach (string[] line in cr) {
        // Process this one line
    }
}

Serialize and Deserialize

You can serialize and deserialize between List<T> and CSV arrays. Serialization supports all basic value types, and it can even optionally support storing null values in CSV cells.

var list = new List<MyClass>();

// Serialize an array of objects to a CSV string
string csv = CSV.Serialize<MyClass>(list);

// Deserialize a CSV back into an array of objects
foreach (var myObject in CSV.Deserialize<MyClass>(csv)) {
    // Use the objects
}

Data Table Support (for older DotNet frameworks)

For those of you who work in older frameworks that still use DataTables, this feature is still available:

// This code assumes the file is on disk, and the first row of the file
// has the names of the columns on it
DataTable dt = CSV.LoadDataTable(myfilename);

// Save a datatable to a file
dt.SaveAsCSV(myfilename, true);

Hand Roll Your Own

The class CSV contains a lot of useful functions for hand rolling your own CSV related code. You can use any of the functions in the CSV class directly.