Обнаружение трещин в задней части тормозной системы автомобиля [закрыто]

Хорошо, я изменил ваше регулярное выражение следующим образом:

$txt = "Codes: C - Connected, S - Static, R - RIP, B - BGP,
       O - OSPF IntraArea (IA - InterArea, E - External, N - NSSA)
       A - Aggregate, K - Kernel Remnant, H - Hidden, P - Suppressed,
       U - Unreachable, i - Inactive

O E       0.0.0.0/0           via 10.140, bond1.30, cost 1:10, age 5  
                              via 10.141, bond1.31  
                              via 10.142, bond1.32  
O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  
O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  
O IA      10.138/29       via 10.140, bond1.30, cost 46, age 1029440  
C         10.141/29    is directly connected, bond2.35
C         10.141/29    is directly connected, bond2.35   
";

$regexp = '#(.) +([A-Z]{1,2}) +([\d.]+/\d+) +via ([\d.]+), ([a-zA-Z0-9.]+), cost [\d:]+, age \d+ +(?:\n +via ([\d.]+), ([a-zA-Z0-9.]+))*#m';
$matches = [];
preg_match_all($regexp, $txt, $matches, PREG_SET_ORDER);
var_dump($matches);

Это выводится:

array(4) {
  [0] =>
  array(8) {
    [0] =>
    string(125) "O E       0.0.0.0/0           via 10.140, bond1.30, cost 1:10, age 5  
                                  via 10.141, bond1.31"
    [1] =>
    string(1) "O"
    [2] =>
    string(1) "E"
    [3] =>
    string(9) "0.0.0.0/0"
    [4] =>
    string(6) "10.140"
    [5] =>
    string(8) "bond1.30"
    [6] =>
    string(6) "10.141"
    [7] =>
    string(8) "bond1.31"
  }
  [1] =>
  array(6) {
    [0] =>
    string(69) "O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  "
    [1] =>
    string(1) "O"
    [2] =>
    string(1) "E"
    [3] =>
    string(9) "10.112/23"
    [4] =>
    string(6) "10.140"
    [5] =>
    string(8) "bond1.30"
  }
  [2] =>
  array(6) {
    [0] =>
    string(69) "O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  "
    [1] =>
    string(1) "O"
    [2] =>
    string(1) "E"
    [3] =>
    string(9) "10.112/23"
    [4] =>
    string(6) "10.140"
    [5] =>
    string(8) "bond1.30"
  }
  [3] =>
  array(6) {
    [0] =>
    string(70) "O IA      10.138/29       via 10.140, bond1.30, cost 46, age 1029440  "
    [1] =>
    string(1) "O"
    [2] =>
    string(2) "IA"
    [3] =>
    string(9) "10.138/29"
    [4] =>
    string(6) "10.140"
    [5] =>
    string(8) "bond1.30"
  }
}

Это не работает, потому что отсутствует третий через

Новая версия, строка за строкой:

$txt = "Codes: C - Connected, S - Static, R - RIP, B - BGP,
       O - OSPF IntraArea (IA - InterArea, E - External, N - NSSA)
       A - Aggregate, K - Kernel Remnant, H - Hidden, P - Suppressed,
       U - Unreachable, i - Inactive

O E       0.0.0.0/0           via 10.140, bond1.30, cost 1:10, age 5  
                              via 10.141, bond1.31  
                              via 10.142, bond1.32  
O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  
O E       10.112/23       via 10.140, bond1.30, cost 46:1, age 2511  
O IA      10.138/29       via 10.140, bond1.30, cost 46, age 1029440  
C         10.141/29    is directly connected, bond2.35
C         10.141/29    is directly connected, bond2.35   
";

$grouped = [];
$i = 0;
foreach (explode("\n", $txt) as $line) {
    $matches = [];
    if (preg_match('#^(.) +([A-Z]{1,2}) +([\d.]+/\d+) +via ([\d.]+), ([a-zA-Z0-9.]+)#', $line, $matches)) {
        array_shift($matches);
        $grouped[++$i] = $matches;
    } else if(preg_match('#^ +via ([\d.]+), ([a-zA-Z0-9.]+)#', $line, $matches)){
        array_push($grouped[$i], $matches[1], $matches[2]);
    }
}
var_dump($grouped);

Теперь она работает:

array(4) {
  [1] =>
  array(9) {
    [0] =>
    string(1) "O"
    [1] =>
    string(1) "E"
    [2] =>
    string(9) "0.0.0.0/0"
    [3] =>
    string(6) "10.140"
    [4] =>
    string(8) "bond1.30"
    [5] =>
    string(6) "10.141"
    [6] =>
    string(8) "bond1.31"
    [7] =>
    string(6) "10.142"
    [8] =>
    string(8) "bond1.32"
  }
  [2] =>
  array(5) {
    [0] =>
    string(1) "O"
    [1] =>
    string(1) "E"
    [2] =>
    string(9) "10.112/23"
    [3] =>
    string(6) "10.140"
    [4] =>
    string(8) "bond1.30"
  }
  [3] =>
  array(5) {
    [0] =>
    string(1) "O"
    [1] =>
    string(1) "E"
    [2] =>
    string(9) "10.112/23"
    [3] =>
    string(6) "10.140"
    [4] =>
    string(8) "bond1.30"
  }
  [4] =>
  array(5) {
    [0] =>
    string(1) "O"
    [1] =>
    string(2) "IA"
    [2] =>
    string(9) "10.138/29"
    [3] =>
    string(6) "10.140"
    [4] =>
    string(8) "bond1.30"
  }
}