Re: Split any number into string of 8-bit hex values (=1 byte)

maybe

 DB<20> print join " ", reverse split /(..)/ , sprintf "%06x\n", 2*10*
+*$_ for 0..5

02  00  00
14  00  00
c8  00  00
d0  07  00
20  4e  00
40  0d  03
 DB<21>
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I'm not sure why you want low bytes first, but please note you had trailing 00s in your example too.

update

this will give you the number of necessary bytes

  DB<29> say 1+int (log (2*10**$_)/log 256)  for 0..5
1
1
1
2
2
3
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Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

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Re^2: Split any number into string of 8-bit hex values (=1 byte) by LanX (Saint) on Aug 30, 2021 at 14:00 UTC
log(0) is undefined, so I designed a custom function hexbytes which returns a list of 0 padded bytes and special casing '00'. Please note how I kept the `reverse` and `join` outside for generic flexibility of use. NB: you must still take care of negative $n! `use strict; use warnings; use feature "say"; sub hexbytes { my ($n)=@_; my $nibbles = $n ? int( log($n)/log 256 )+1 : 1 ; # 00 has no log $nibbles = 2; # 2 nibbles = 1 byte return sprintf( '%0x', $nibbles, $n ) =~ /(..)/g; } say "$_ => ", join " ", reverse hexbytes($_) for 0,2,20,200,2000,20000 +,200000;` [download] `C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/hex_reverse.pl 0 => 00 2 => 02 20 => 14 200 => c8 2000 => d0 07 20000 => 20 4e 200000 => 40 0d 03 Compilation finished at Mon Aug 30 15:57:08` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]
Re^3: Split any number into string of 8-bit hex values (=1 byte) by LanX (Saint) on Aug 30, 2021 at 14:29 UTC
Here a more generic solution, the grouping is free now (left the reverse out for better testing) `use strict; use warnings; use feature "say"; sub hexgroups { my ( $n, $group ) = @_; die "Can't handle negative $n" if $n <0; $group //= 2; # default 1 byte = 2 nibbles my $nibbles = $n ? int( log($n)/log 16*$group ) +1 : 1 ; # 00 has no log $nibbles = $group; # zero padding my @list = sprintf( '%0x', $nibbles, $n ) =~ /(.{$group})/g; return @list; } for my $n (0, map { 2"1e$_"} 0..10) { say "$n => "; say "\t"x2, join " ", hexgroups($n, $_) for 1,2,3,4; }` [download] Read more... (2 kB)	[reply] [d/l] [select]