Hello tajinderpalsingh61, and welcome to the Monastery!

To expand on swl’s answer, here is one approach:

use strict;
use warnings;
use Data::Dump;
use Math::BigInt;

my  $string = '1677259342285725925376';
my  $n      =  Math::BigInt->new($string);
my  @bytes  =  map { ord } split //, $n->to_bytes();
    @bytes  =  map { $_ >= 128 ? $_ - 256 : $_ } @bytes;
dd \@bytes;

[download]

Output:

16:16 >perl 2015_SoPW.pl
[90, -20, -90, 53, 78, -38, 2, -128, 0]

16:16 >

[download]

Explanation: Math::BigInt->to_bytes returns a reprsentation of the integer as a byte string. split // splits that string into its component bytes. ord() turns a byte from a character into a number (its numerical representation).

The useful function map applies the expression in braces to each element of the list it receives, and returns the resulting new list; so I’ve used it twice, once to convert byte characters into their numerical representations, and again to convert those numbers above 127 into their corresponding signed 8-bit integers.

For the ?: ternary operator, see Conditional Operator. And Data::Dump is a useful CPAN module for displaying complex data structures.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: How to convert bigint to bytearray in perl by Athanasius
in thread How to convert bigint to bytearray in perl by tajinderpalsingh61

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