Rename Mac OS X ScreenShots to something saner — shorter :)

#!/bin/bash
# ( 08/02/12 05:06 AM ) - perhaps a better method described here:
# http://stackoverflow.com/questions/11774560/batch-rename-screen-shots-on-mac-os-x

# Rename Mac OS X Screen Shots by finding the pattern and replacing it to a
# shorter string length.

# Change into the Destop directory which is where screenshots are usually taken
cd /Users/$USER/Desktop

# do the renaming bits
for i in *; do
     pattern="Screen\ Shot\ 20([0-9]{1,2})-([0-9]{1,2})-([0-9]{1,2})\ at\ ([0-9]{1,2})\.([0-9]{1,2})\.([0-9]{1,2})\ ([APM]{2})\.png";
     replacement="ss.\2-\3-\1 \4.\5.\6.\7.\png";
     new_filename=`/bin/echo $i | /usr/bin/sed -E "s/$pattern/$replacement/"`;

     if [[ "$new_filename" != "$i" ]]
     then
          /bin/mv "$i" "$new_filename";
          /bin/echo "new_filename: $new_filename";
          /bin/echo "old_filename: $i";
     fi
done