How to find duplicate files with same name but in different case that exist in same directory in Linux?

Question

How can I return a list of files that are named duplicates i.e. have same name but in different case that exist in the same directory?

I don't care about the contents of the files. I just need to know the location and name of any files that have a duplicate of the same name.

Example duplicates:

/www/images/taxi.jpg /www/images/Taxi.jpg 

Ideally I need to search all files recursively from a base directory. In above example it was /www/

Answer 1

The other answer is great, but instead of the "rather monstrous" perl script i suggest

perl -pe 's!([^/]+)$!lc $1!e' 

Which will lowercase just the filename part of the path.

Edit 1: In fact the entire problem can be solved with:

find . | perl -ne 's!([^/]+)$!lc $1!e; print if 1 == $seen{$_}++' 

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Edit 3: I found a solution using sed, sort and uniq that also will print out the duplicates, but it only works if there are no whitespaces in filenames:

find . |sed 's,\(.*\)/\(.*\)$,\1/\2\t\1/\L\2,'|sort|uniq -D -f 1|cut -f 1 

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Edit 2: And here is a longer script that will print out the names, it takes a list of paths on stdin, as given by find. Not so elegant, but still:

#!/usr/bin/perl -w  use strict; use warnings;  my %dup_series_per_dir; while (<>) {     my ($dir, $file) = m!(.*/)?([^/]+?)$!;     push @{$dup_series_per_dir{$dir||'./'}{lc $file}}, $file; }  for my $dir (sort keys %dup_series_per_dir) {     my @all_dup_series_in_dir = grep { @{$_} > 1 } values %{$dup_series_per_dir{$dir}};     for my $one_dup_series (@all_dup_series_in_dir) {         print "$dir\{" . join(',', sort @{$one_dup_series}) . "}\n";     } }