#! perl -w use strict; my($file); my(%upload,%seen); %upload=(a=> 'dog', b=> 'cat', c=> 'llama', d => 'dog' ); for (keys %upload){ $file=$upload{$_}; if(defined $seen{$file}) { print "
Duplicate filename found: $file
\n"; exit; } $seen{$file}=$file; print "
Uploaded $file
"; } #### #! perl -w use strict; my(%upload,%seen); my($counter,$file,$old); %upload=(a=> 'dog.gif', b=> 'cat.gif', c=> 'llama.gif', d => 'dog.gif' ); for (keys %upload){ $file=$upload{$_}; if(defined $seen{$file}) { $old=$file; while (defined $seen{$file}){ $file=$old; $counter++; $file=join('.',$file,$counter); } } $seen{$file}=$file; print "
Uploaded ",$file,"
\n"; }