mdfind

List files matching a query. More information: https://keith.github.io/xcode-man-pages/mdfind.1.html.

Find a file by its name:

mdfind -name {{file}}

Find a file by its content:

mdfind "{{query}}"

Find a file containing a string, in a given directory:

mdfind -onlyin {{directory}} "{{query}}"