If you ever need to query the Cygwin package database, cygcheck is the command to use. For example, you may want to determine the package containing a certain program in which you are interested in installing.
Find the package containing a particular file.
cygcheck -f /usr/bin/less
List the contents of a package.
cygcheck -l less
Search for the regular expression in the entire Cygwin database.
cygcheck -p 'less\.exe'