libalpm

libalpm (Arch Linux Package Management Library) is a C library that provides a stable, high-level interface to Arch Linux's package management system. It serves as the core backend for pacman, the Arch package manager, and can be used by other tools to manipulate Arch packages and databases.

Its responsibilities include managing the local package database, synchronizing with remote databases, querying packages and dependencies, and planning and executing package transactions such as installations, removals, and upgrades. Libalpm handles dependency resolution and conflict detection at the transaction level, and coordinates with signing and verification processes during package installation. It abstracts the details of package files, databases, and cache storage, presenting a uniform API to front-ends.

API and architecture: Libalpm provides a C API with opaque handle types such as alpm_handle_t, alpm_db_t, alpm_pkg_t, alpm_pkglist_t, and alpm_transaction_t. The library is designed to be used by front-ends to implement custom package management workflows, while pacman uses libalpm as its interface to the package database and to perform install operations.

Development and licensing: Libalpm is part of the Arch Linux packaging ecosystem and is maintained by the Arch community. It is licensed under the GNU General Public License.

See also: pacman, Arch Linux, package management.