use strict; use warnings; use feature 'say';
use Data::Dumper; $Data::Dumper::Sortkeys = $Data::Dumper::Indent = 1;

chomp( my $input = <DATA> );

my ( $first, $txt ) = split / /, $input, 2;

my %pairs = $txt =~ /
    ( \w+ )             # capture key
    =                   # separator
    (                   # capture value
      (?:                 # group (but don't additionally capture)
        (?!\w+=)            # (must not be followed by the next key-separator)
        .+?                 # at least one character (even if just the whitespace), non-greedy
      )+                  # at least one of those
    )                   # end value
/msxg;

$pairs{ $first } = '';

# trim trailing whitsepace from values
$_ =~ s/ $// for values %pairs;

say Dumper \%pairs;

__END__
eab12345 id=00000 pgrp=abcdefgh groups=abcdefgh home=/home/eab12345 shell=/usr/bin/ksh gecos=AB/C/Y0000/ABC/XYZ RTYUI, LMNOP *CONTRACTOR* (AS 00000) auditclasses=general,files,TCPIP login=true su=true rlogin=true daemon=true admin=false sugroups=ALL admgroups= tpath=nosak ttys=ALL expires=0 auth1=SYSTEM auth2=NONE umask=00 registry=AD SYSTEM=AD logintimes= loginretries=5 pwdwarntime=5 account_locked=false minage=0 maxage=13 maxexpired=0 minalpha=1 minother=1 mindiff=1 maxrepeats=2 minlen=8 histexpire=13 histsize=8 pwdchecks= dictionlist=/abc/def/ghi/jkl default_roles= fsize=-1 cpu=-1 data=-1 stack=65536 core=000000 rss=65536 nofiles=2000 time_last_login=1512632113 time_last_unsuccessful_login=1505304923 tty_last_login=ssh tty_last_unsuccessful_login=ssh host_last_login=0.000.000.000 host_last_unsuccessful_login=0.000.000.000 unsuccessful_login_count=0 roles=

##</code><code>##

$VAR1 = {
  'SYSTEM' => 'AD',
  'account_locked' => 'false',
  'admgroups' => '',
  'admin' => 'false',
  'auditclasses' => 'general,files,TCPIP',
  'auth1' => 'SYSTEM',
  'auth2' => 'NONE',
  'core' => '000000',
  'cpu' => '-1',
  'daemon' => 'true',
  'data' => '-1',
  'default_roles' => '',
  'dictionlist' => '/abc/def/ghi/jkl',
  'eab12345' => '',
  'expires' => '0',
  'fsize' => '-1',
  'gecos' => 'AB/C/Y0000/ABC/XYZ RTYUI, LMNOP *CONTRACTOR* (AS 00000)',
  'groups' => 'abcdefgh',
  'histexpire' => '13',
  'histsize' => '8',
  'home' => '/home/eab12345',
  'host_last_login' => '0.000.000.000',
  'host_last_unsuccessful_login' => '0.000.000.000',
  'id' => '00000',
  'login' => 'true',
  'loginretries' => '5',
  'logintimes' => '',
  'maxage' => '13',
  'maxexpired' => '0',
  'maxrepeats' => '2',
  'minage' => '0',
  'minalpha' => '1',
  'mindiff' => '1',
  'minlen' => '8',
  'minother' => '1',
  'nofiles' => '2000',
  'pgrp' => 'abcdefgh',
  'pwdchecks' => '',
  'pwdwarntime' => '5',
  'registry' => 'AD',
  'rlogin' => 'true',
  'roles' => '',
  'rss' => '65536',
  'shell' => '/usr/bin/ksh',
  'stack' => '65536',
  'su' => 'true',
  'sugroups' => 'ALL',
  'time_last_login' => '1512632113',
  'time_last_unsuccessful_login' => '1505304923',
  'tpath' => 'nosak',
  'tty_last_login' => 'ssh',
  'tty_last_unsuccessful_login' => 'ssh',
  'ttys' => 'ALL',
  'umask' => '00',
  'unsuccessful_login_count' => '0'
}