Question

I want to get the unique elements (lines) from a file which I will further send through email.
I have tried 2 methods but both are not working:

1st way:

my @array = "/tmp/myfile.$device";
my %seen = ();
my $file = grep { ! $seen{ $_ }++ } @array;

2nd way :

my $filename = "/tmp/myfile.$device";
cat $filename |sort | uniq > $file

How can I do it?

Answer 1

If you rig the argument list, you can make Perl open the file automatically, using:

perl -n -e 'BEGIN{@ARGV=("/tmp/myfile.device");} print if $count{$_}++ == 0;'