I often rename files immediately after downloading and stick them in a folder somewhere for later reference. But I also often forget what I've already downloaded. So I wrote this bash shell script to use Spotlight to find files that match a file's name or its size and kind.
Usage, in Terminal:
dupecheck filename
For example, for a file called 0.pdf, output might look like this (line breaks added for a narrower display):
Possible matches based on filename:
/Users/whoever/Desktop/0.pdf
Possible matches based on size and kind:
/Users/whoever/Desktop/0.pdf
/Users/whoever/Desktop/Data/anthro articles/sahlins-1999.pdf
/Users/whoever/Desktop/Data/html/oldcourses/
intro/secure/sahlins-sweetness.pdf
/Users/whoever/Documents/archives/another backup/
blahblah/public_html/intro/secure/sahlins1999-sweetness.pdf
/Users/whoever/Desktop/Data/html/blahblah/readings/3/sahlins99.pdf
So it turns out I just downloaded a file that I already have four copies of under different names and locations.
cd __OBJ_PARENT_PATH__
dupecheck __OBJ_NAME__
Execution Mode should be set to Terminal.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20061003163429425