CSV Dialects and Encodings

"CSV" covers many dialects: comma or semicolon delimiters, quoted or unquoted fields, UTF-8 with or without a byte order mark, regional decimal separators. OfficeIMO.CSV reads and writes each of them explicitly, so the file you write back matches what the receiving system expects.

Detect or set the delimiter

C#

using System.Text;
using OfficeIMO.CSV;

// Detect the delimiter from the first records
CsvDocument detected = CsvDocument.Load("export.csv", new CsvLoadOptions { DetectDelimiter = true });

// Or set it explicitly
CsvDocument semicolon = CsvDocument.Load("export-pl.csv", new CsvLoadOptions {
    Delimiter = ';',
    Encoding = Encoding.UTF8,
    HasHeaderRow = true
});

PowerShell

Import-OfficeCsv -Path .\export.csv -DetectDelimiter
Import-OfficeCsv -Path .\export-pl.csv -Delimiter ';'

CLI

officeimo tabular convert export-pl.csv export.csv --delimiter ';' --output-delimiter ','

Write for a regional spreadsheet

Use the culture that the reader expects for numbers and dates, and the matching delimiter.

C#

using System.Globalization;
using OfficeIMO.CSV;

var rows = new[] { new { Product = "Widget", Price = 9.99m } };

CsvDocument.FromObjects(rows, delimiter: ';', culture: new CultureInfo("de-DE"))
    .Save("prices-de.csv");

PowerShell

$data | Export-OfficeCsv -Path .\export.csv -UseCulture -Culture pl-PL

Use a policy profile

Profiles set a consistent group of input and output rules in one call:

C#

using OfficeIMO.CSV;

CsvLoadOptions input = CsvProfiles.CreateLoadOptions(CsvProfile.Strict);
input.Delimiter = ';';
CsvDocument document = CsvDocument.Load("input.csv", input);

document.Save("for-excel.csv", CsvProfiles.CreateSaveOptions(CsvProfile.Spreadsheet));
document.Save("copy.tsv", CsvProfiles.CreateSaveOptions(CsvProfile.Tsv));

Control the output encoding

C#

using System.Text;
using OfficeIMO.CSV;

CsvDocument.Load("input.csv").Save("output.csv", new CsvSaveOptions {
    Encoding = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false),
    NewLine = "\n"
});

PowerShell

Import-OfficeCsv -Path .\input.csv | Export-OfficeCsv -Path .\output.csv -Encoding ([System.Text.UTF8Encoding]::new($false)) -NewLine "`n"

Limits and reference

Limits: delimiter detection samples at most 64 Ki characters and 64 records; it falls back to the configured delimiter when the sample is inconclusive. See the CSV package row.

Reference: OfficeIMO.CSV API · Import-OfficeCsv