How to echo directories containing matching file with Bash?

Question

I want to write a bash script which will use a list of all the directories containing specific files. I can use find to echo the path of each and every matching file. I only want to list the path to the directory containing at least one matching file.

For example, given the following directory structure:

dir1/
    matches1
    matches2
dir2/
    no-match

The command (looking for 'matches*') will only output the path to dir1.

As extra background, I'm using this to find each directory which contains a Java .class file.

Answer 1

find -name '*.class' -printf '%h\n' | sort -u

From man find:

-printf format

%h Leading directories of file’s name (all but the last element). If the file name contains no slashes (since it is in the current directory) the %h specifier expands to ".".

Answer 2

GNU find

find /root_path -type f -iname "*.class" -printf "%h\n" | sort -u

Answer 3

find / -name *.class -printf '%h\n' | sort --unique