You can certainly do it using pack but you will have to take into account the alignment of the data in the struct.

It is probably better to use Convert::Binary::C

Here is an example from the docs:

  use Convert::Binary::C;
  
  #---------------------------------------------
  # Create a new object and parse embedded code
  #---------------------------------------------
  my $c = Convert::Binary::C->new->parse(<<ENDC);
  
  enum Month { JAN, FEB, MAR, APR, MAY, JUN,
               JUL, AUG, SEP, OCT, NOV, DEC };
  
  struct Date {
    int        year;
    enum Month month;
    int        day;
  };
  
  ENDC
  
  #-----------------------------------------------
  # Pack Perl data structure into a binary string
  #-----------------------------------------------
  my $date = { year => 2002, month => 'DEC', day => 24 };
  
  my $packed = $c->pack('Date', $date);
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--
John.