An obvious mistake

###### OUT PATH DETAILS ######$jnl=$ARGV[0];

should be

###### OUT PATH DETAILS ######

$jnl=$ARGV[0];
[download]

But don't do this, better

my ($jnl,$artno,$outpath,$proftxt)=@_;

instead

my $jnl;
my $artno;
my $outpath;
my proftxt;

$jnl=$ARGV[0];
$artno=$ARGV[1];
$outpath=$ARGV[2];
$proftxt=$ARGV[3];
[download]

What's the purpose of your code?