Community.Archives.Rpm 1.2.0

Community.Archives.Rpm

A fast and efficient forward-only reader for Rpm archives.

• 🚀 Fast and efficient: Only extracts matched file. Forward-only access. Uses Task to offload IO to separate threads.
• 😀 Licensed under MIT. Similar projects are licensed under GPL.
• 😍 100% test coverage

This package is part of Gitii/Community.Archives: A collection of libraries that support reading various popular archives.

Supported frameworks

• .Net Standard 2.1
• .Net 5
• .Net 6

On any platform that's supported by the above frameworks, including Windows, Linux and MacOS.

Reader specifications

RpmArchiveReader is implemented based on Cap. 24. RPM Package File Structure.

• Only a subset of all metadata is extracted.

• A rpm file contains an cpio archive. It contains all files. RpmArchiveReader uses a CpioArchiveReader under the hood to extract the files.

Getting started

Extract all or specific files

var reader = new RpmArchiveReader();

await foreach (
    var entry in reader
        .GetFileEntriesAsync(stream, IArchiveReader.MATCH_ALL_FILES)
) {
    // entry.Name
    // entry.Content
    Console.WriteLine($"Found file {entry.Name} ({entry.Content.Length} bytes)")
}

Extract specific files only

var reader = new RpmArchiveReader();

// use regular expression to match files (path + file name)
await foreach (
    var entry in reader
        .GetFileEntriesAsync(stream, "[.]md$", "[.]txt$")
) {
    // found a Markdown or text file
}

Extract metadata of the archive

var reader = new RpmArchiveReader();

var metaData = await reader.GetMetaDataAsync(stream);

Console.WriteLine(metaData.Package); // for example: "gh"
Console.WriteLine(metaData.Version); // for example: "2.4.0"

Rpm package file name parser

The rpm package file name follows a specific naming convention: <name>-<version>-<release>-<arch>.

The class RpmPackageNameParser is able to split this string in it's components:

var reader = new RpmPackageNameParser();

// parse it
if (reader.TryParse("mypackage-1.2-1", out var name)) {
    Console.WriteLine(name.Name); // mypackage
    Console.WriteLine(name.Version); // 1.2
    Console.WriteLine(name.Release); // 1
    Console.WriteLine(name.Architecture); // <null>, arch is optional.
}

// only validate it
reader.IsValid("mypackage-1.2-1") // true
reader.IsValid("mypackage-1.2-1-x86") // true
reader.IsValid("mypackage") // false

Rpm package version comparison

Version strings in rpm packages follow a strict naming convention but it's not simple to understand & compare.

The class RpmVersion has a Compare function that does the heavy lifting.

It returns either

• 0 (same version)

• +1 (left version is greater than right version)

• -1 (left version is lower than right version)

Examples:

RpmVersion.Compare("1.0", "1.0") // 0  -> 1.0 == 1.0
RpmVersion.Compare("1.0", "2.0") // -1 -> 1.0 <  2.0
RpmVersion.Compare("2.0", "1.0") // +1 -> 2.0 >  1.0
// and now some of the fun ones
RpmVersion.Compare("1.0^20160102", "1.0^20160101^git1") // +1
RpmVersion.Compare("1.0^git1", "1.0^git1~pre") // +1