Everyone that has been using Gentoo for a while now knows about tools such as qlist that show you the list of files installed by an (installed) package, or qfile that allows you to find which package provided a particular file on your system.

One thing lacking is to be able to find out which package would provide a file. Unlike the previous tools, this tool cannot rely on the information found on your system as the package isn't installed yet.

There have been projects in the past that attempted to provide such functionality, almost always through an online queryable database. Many haven't survived, due to too high expectations or little server infrastructure resources. But it seems like PortageFileList is to stay for a while.

The project not only offers an online interface for querying information, it also provides a package (app-portage/pfl) that allows you to query their infrastructure from the command line. The package provides a tool called e-file which supports SQL-like syntax for the queries.

~$ e-file '%bin/xdm'

The above command will then display, using the well-known emerge/Portage output, which package provides the file (as well as which file was matched by the query).

Definitely a nice tool to have around. Thanks guys of PortageFileList!