preg_split by space and tab outside quotes

Question

I am trying to get preg_split() to split the following 2 strings, by space/tab (needs to work on both).

autodiscover.microsoft.com. 3600 IN A   131.107.125.5

and

microsoft.com.      3600    IN  TXT "v=spf1 include:_spf-a.microsoft.com include:_spf-b.microsoft.com include:_spf-c.microsoft.com -all"

The trick is that in the second instance the last part with quotes, should not be split.

From looking on the StackOverflow, I have found that I probably need to use this.

$results = preg_split("/'[^']*'(*SKIP)(*F)|\x20/", $str);

Sadly I cannot get it to work. I have tried several things like this for instance, but nothing works.

"\s+"(*SKIP)(*F)|\x20

Thanks in advance.

Answer 1

Just split your input according to the below regex. \h+ matches one or more horizontal space characters ie, spaces , tabs.

(?:'[^']*'|"[^"]*")(*SKIP)(*F)|\h+

(?:'[^']*'|"[^"]*") matches all the single and double quotes strings. (*SKIP)(*F) causes the match to fail and picks up all the characters which are matched by the pattern present just after to |. In our case, it's \h+ which matches one or more horizontal spaces.

DEMO

$str = 'microsoft.com.      3600    IN  TXT "v=spf1 include:_spf-a.microsoft.com include:_spf-b.microsoft.com include:_spf-c.microsoft.com -all"';
$match =  preg_split('~(?:\'[^\']*\'|"[^"]*")(*SKIP)(*F)|\h+~', $str);
print_r($match);

Output:

Array
(
    [0] => microsoft.com.
    [1] => 3600
    [2] => IN
    [3] => TXT
    [4] => "v=spf1 include:_spf-a.microsoft.com include:_spf-b.microsoft.com include:_spf-c.microsoft.com -all"
)