PKGtar

Pkgtar is a packaging format and accompanying command-line tool used to create, inspect, and distribute software packages that are stored as tar-based archives. It appears in several Unix-like packaging ecosystems as a standard means of bundling a package’s file payload together with its installation metadata and, optionally, installation scripts. The exact specifications of pkgtar can vary between implementations, but the general model centers on tar archives with embedded or accompanying metadata.

A pkgtar package typically uses a name such as name-version.pkg.tar.{gz,bz2,xz} and consists of two main parts: the payload, which mirrors a filesystem layout to be installed, and a metadata component that records package name, version, license, dependencies, maintainers, and other descriptive fields. The archive may include a separate manifest or metadata file, and the payload is commonly compressed with a standard compressor to reduce distribution size.

Pkgtar implementations define how metadata is structured and how dependencies are expressed. While end users rarely invoke pkgtar directly for daily usage, the tool provides commands to create packages from sources or recipes, list and inspect metadata, verify archive integrity via checksums or digital signatures, and extract contents for inspection or manual installation. In practice, package managers in the ecosystem typically handle installation, dependency resolution, and post-installation steps, with pkgtar serving as the packaging artifact format.

Security and integrity considerations are central. Packages are often signed and accompanied by checksums in a manifest to prevent tampering. Reproducible builds and strict metadata validation help ensure consistent, secure installations across systems.

See also: tar, gzip, bzip2, xz, package manager, manifest file.