@a1 = (1, 2, 3);
open FILEHANDLE, ">array.dat" or die "Can not open array.dat";

print FILEHANDLE "@a1";

close FILEHANDLE;

open FILEHANDLE2, "<array.dat" or die "Can not open array.dat";

@a2 = split(" ", <FILEHANDLE2>);

print "@a2";

close FILEHANDLE2;