#!/bin/sh

# change any uppercase letters in file and directory
# names in the current directory and below.

# License: LGPLv2

# note filenames with \1 or \n will cause problems

# note this is still much slower than it could be,
# as there is a separate mv executed for each file/dir.
# It would be much more efficient to pass the output
# of this to a python script for e.g. that does the rename

find -depth \( -type f -o -type d \) |
LC_ALL=C grep -E "/[^/]*[A-Z]+[^/]*$" | #only process upcase names
sed -e '
{
    #escape any chars that could cause problems
    #s/\([]"{}\$]\)/\\\1/g

    #keep orig path in hold space
    h

    #put basename in pattern space
    s/.*\/\([^/]*$\)/\1
/

    #lowercase basename
    y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/

    #exchange pattern and hold space
    x

    #format mv args 1
    s/\(.*\/\)\([^/]*$\)/\1\2
\1/

    #format mv args 2
    G
}' |

tr -d '\n'   |    #format mv args 3
tr '
' '\0' |    #format mv args 4
xargs -r0 -n2 mv  #execute mv