use strict;
sub get_bash_login_env {
  local %ENV;
  my $env = `echo env | bash --login`;
  if (wantarray) {
    $env =~ s/\\(.)/$1/gs;
    return map {split /=/, $_, 2} map {split /\n/, $_} $env;
  }
  else {
    return $env;
  }
}

# And a demo of how to use it

use Data::Dumper;
%ENV = (%ENV, get_bash_login_env());
print Dumper(\%ENV);