I wanna extract the header line from 2 protein sequences for example: I created the file, then I gave the file name, then I wanna extract header, then from the second sequence.

here I showed what's the header in below:

gi|628601924|ref|NP_001278775.1| DNA-binding protein Ikaros isoform 16 [Homo sapiens] These are my protein fasta with heder that i wanna extract the header from them:

gi|628601924|ref|NP_001278775.1| DNA-binding protein Ikaros isoform 16 [Homo sapiens] MDADEGQDMSQVSGKESPPVSDTPDEGDEPMPIPEDLSTTSGGQQSSKSDRVVVTYGADDFRDFHAIIPK SFSLLEL

gi|628601926|ref|NP_001278776.1| DNA-binding protein Ikaros isoform 16 [Homo sapiens] MDADEGQDMSQVSGKESPPVSDTPDEGDEPMPIPEDLSTTSGGQQSSKSDRVVVTYGADDFRDFHAIIPK SFSLLEL

I wrote this command:

   print "Please enter a file name: ";
   $file = <>;
   open INFILE, $file;

   $line = <INFILE>;

   while (defined($line = <INFILE>)){
   }
   chomp $line;

if ($line =~ /^>(S+)\s*(.*)$/;){

 $id = $1; # what should I write here to activate these $1 and $2

 $description = $2;

   print substr($1 $2); #what else should I add here
   }

   } else {# I need to write some thing here, like this it's not header don't  extract it 

   }
   next; # is this enough for going to the next sequence 

   close INFILE;