From ArchWiki

[edit] Description

Qfile is a script for using the package search at www.archlinux.org.

For comments or suggestions, contact the author (EcchiM).

[edit] Download

The latest version of the script can be found here: http://koios.de/~marcel/qfile/

[edit] Usage

[marcel@eris ~]$ ./qfile --help
qfile 0.01
Usage: qfile [OPTION]... [FILENAME]
Options:
  -r REPOSITORY         specify Repository (All, Current, Extra, Unstable,
                        Testing)
  -c CATEGORY           specify Category (All, Base, Daemons, Devel, Editors, 
                        Emulators, Games, Gnome, I18n, KDE, Kernels, Lib, 
                        Modules, Multimedia, Multimedia-plugins, Network, 
                        Office, Science, System, X11, X11-drivers, X11-libs,
                        Xfce4)
  -u DATE               specify last update
  --help                display this help and exit

[edit] Examples

Searching in unstable, category gnome, "gnome" since 01-01-2005:

[marcel@eris ~]$ ./qfile -r unstable -c gnome -u 01-01-2005 gnome
Unstable        gnome   1.4.0-1         gnome-system-tools
Unstable        gnome   1.0beta6-1      gtoaster
Unstable        gnome   1.4.0-1         system-tools-backends

Searching "libgssapi.so.4"

[marcel@eris ~]$ ./qfile /libgssapi.so.4
Current         lib     0.7.2-1         heimdal

The leading / tells the package search to search for a file name instead of a package name or description. Note that due to restrictions to the online search engine, the search may fail with very short file names such as ls.