Unpack is very useful if you have multiple items you want to unpack, and if you're familiar with the Perl 5 unpack then there's the P5pack module (which isn't a full implementation of Perl 5's unpack, but is useful for simpler things). If you want to unpack something from the middle of a Buf or Blob then you'll need to explicitly skip over the beginning of the buffer using "x", whereas read-int32 has an explicit position argument.
On Fri, 8 Feb 2019 at 22:00, The Sidhekin <sidhe...@gmail.com> wrote: > On Fri, Feb 8, 2019 at 7:36 AM Todd Chester via perl6-users < > perl6-us...@perl.org> wrote: > >> I am dealing with a Buf what includes 32 bit integers, but >> they are entered somewhat backwards as view with hexedit: >> >> AE 5D 5C 72 represents the number 725C5DAE >> >> This is what I have come up with to convert this type of >> number in a buffer to and integer >> >> $ p6 'my Buf $x=Buf.new(0xAE,0x5D,0x5C,0x72); my int32 $i=$x[3] +< 0x18 >> + $x[2] +< 0x10 + $x[1] +< 0x08 + $x[0]; say $x; say $i.base(0x10);' >> >> Buf:0x<ae 5d 5c 72> >> 725C5DAE >> >> >> Is there a more "elegant" way to do this? >> > > The "elegant" way I'd do it, is using unpack(): > https://docs.perl6.org/routine/unpack > > It's experimental, so a declaration is needed, but Buf does Blob, so > otherwise, it's straight to the point: > > $ perl6 -e 'use experimental :pack; my Buf > $x=Buf.new(0xAE,0x5D,0x5C,0x72); say $x.unpack("L").base(0x10);' > 725C5DAE > $ > > > Eirik > >
