#! /bin/bash
# Changes every filename in working directory to all lowercase.
# set -x
# Inspired by a script of John Dubois,
# which was translated into into Bash by Chet Ramey,
# and considerably simplified by Mendel Cooper, author of this document.


#for filename in *                # Traverse all files in directory.
##for filename in `find . -maxdepth 1 -type f ! -name ".*"`
##do
##   fname=`basename $filename`
##   n=`echo $fname | tr a-z A-Z`  # Change name to lowercase.
##   if [ "$fname" != "$n" ]       # Rename only files not already lowercase.
##   then
##     mv $fname $n
##   fi  
##done   
##
##exit 0


# Code below this line will not execute because of "exit".
#--------------------------------------------------------#
# To run it, delete script above line.

# The above script will not work on filenames containing blanks or newlines.

# Stephane Chazelas therefore suggests the following alternative:


for filename in *    # Not necessary to use basename,
                     # since "*" won't return any file containing "/".
do n=`echo "$filename/" | tr '[:upper:]' '[:lower:]'`
#do n=`echo "$filename/" | tr '[:lower:]' '[:upper:]'`
#                             POSIX char set notation.
#                    Slash added so that trailing newlines are not
#                    removed by command substitution.
   # Variable substitution:
   n=${n%/}          # Removes trailing slash, added above, from filename.
   [[ $filename == $n ]] || mv "$filename" "$n"
                     # Checks if filename already lowercase.
done

exit 0