Rename all JPG file extensions to JPEG, recursively and handles sub-directories also.

#!/bin/bash
 
function rename_extension
{
  # Change all .jpg to .jpeg,
  for file in $1/*.jpg; do
    mv $file $1/`basename $file .jpg`.jpeg;
    echo $file;
  done;
 
  # Recurse directories.
  for d in $1/*; do
    if test -d $d; then
      rename_extension $d;
    fi;
  done;
}
 
dir=`pwd`;
 
rename_extension $dir;