Loq.Classic 0.1.79

Loq.Classic

Drop-in replacement for Microsoft Log Parser 2.2's MSUtil.LogQuery COM API, for .NET.

loq is a cross-platform reimplementation of MS Log Parser in Rust. Loq.Classic wraps the native loq library in the same shape as the original COM interface so existing scripts and applications can be ported with minimal changes — most of the time you only need to replace the COM object instantiation.

Install

dotnet add package Loq.Classic

The package transitively pulls in Loq.Native, which ships native binaries for win-x64 and linux-x64 automatically.

Quick start — drop-in replacement

Classic ASP / VBScript:

Set oQuery = CreateObject("MSUtil.LogQuery")
Set oRS = oQuery.Execute("SELECT * FROM C:\logs\access.log")

.NET equivalent with Loq.Classic:

using Loq.Classic;

using var query = new LogQuery();
using var rs = query.Execute(@"SELECT * FROM C:\logs\access.log");
while (!rs.AtEnd)
{
    var record = rs.GetRecord();
    Console.WriteLine(record.GetValue("c-ip"));
    rs.MoveNext();
}

With format-specific input contexts

Same API surface as the COM COM*InputContext types:

using Loq.Classic;
using Loq.Classic.InputFormats;

var input = new COMTSVInputContext
{
    headerRow = false,
    nSkipLines = 1,
    lineFilter = "+2026-04-23"
};

using var query = new LogQuery();
using var rs = query.Execute(
    "SELECT Field1, Field2 FROM 'D:\\logs\\sample.txt'",
    input);

Supported input contexts: COMCSVInputContext, COMTSVInputContext, COMW3CInputContext, COMIISW3CInputContext, COMIISIISInputContext, COMIISNCSAInputContext, COMIISBINInputContext, COMTextLineInputContext, COMTextWordInputContext, COMURLScanLogInputContext, COMHttpErrorInputContext, COMNetMonInputContext, COMRegistryInputContext, COMFileSystemInputContext, COMXMLInputContext.

Supported output contexts (for ExecuteBatch): CSV, TSV, JSON, XML, W3C, IIS, DATAGRID, SQLite, SQL Server, MySQL / Aurora MySQL, Chart (PNG/SVG), and several more. For Aurora MySQL writes, use COMMySQLOutputContext with a mysql://...?ssl-mode=REQUIRED URL pointing at the writer cluster endpoint — see docs/output-formats/mysql.md.

SQL syntax

Same as MS Log Parser 2.2 — see the LP22 syntax reference for the supported SELECT/FROM/WHERE/GROUP BY/ORDER BY/USING/INTO clauses, the 100+ built-in functions (SUBSTR, QUANTIZE, EXTRACT_TOKEN, TO_TIMESTAMP, HASHMD5, etc.), and LP22-isms like comma-separated FROM (FROM 'a','b','c' reads from all listed files), wildcard FROM paths (case-insensitive on every platform, matching NTFS), and INTO chart targets.

What's not the same as LP22

• Execute returns a LogRecordSet (not ILogRecordset COM type) — same shape, different namespace.
• Fully cross-platform: works on Linux and macOS in addition to Windows. The native library is bundled per-RID inside Loq.Native.
• IDisposable — call Dispose() (or using var) to release native handles. The original COM API relied on COM ref-counting.

Need a more idiomatic .NET API?

If you don't need LP22 compat — strongly-typed results, IEnumerable<T>, DataTable conversion — install the Loq package instead.

Source / issues

• Source: https://github.com/chaynes81-ux/loq
• Releases & docs: https://chaynes81-ux.github.io/loq-releases/
• Issues: file at the GitHub repo above.

License

MIT.