while (<>){
 chomp;
 print; print "\n";
}

foreach (@ARGV) {
 chomp;
 print "$_\n";
}

#@ARGV = qw /file1 file2/;
while (<>){ #print content of  file1 then file2
 chomp;
 print "$_\n";
}

my @array=(1,2,3);

print "@array";
print "@array\n";

printf("%6d\n", 42);

unix    \n
dos     \r\n

vi unix
 1
 2
 3
cp unix dos
unix2dos dos

file unix
file dos

od -c unix
od -c dos