PHP script to receive all zfs snapshot of dataset from remote machine to local

zfs_sync_snapshots.php

<?php

$remoteIP = $argv[1];
$remoteDataset = $argv[2];

$localDataset = $argv[3];

if($argc!=4) exit('usage: php sync.php <remote ip> <remote dataset> <local dataset>'.PHP_EOL);

$cmd_zfs = "zfs list -t snapshot $remoteDataset | cut -d ' ' -f 1 | cut -d '@' -f 2 | tail -n +2";
$cmd_zfs_local = "zfs list -t snapshot $localDataset | cut -d ' ' -f 1 | cut -d '@' -f 2 | tail -n +2";
$cmd_ssh = "ssh $remoteIP $cmd_zfs";

$remotesnapshots = [];
exec($cmd_ssh,$remotesnapshots);

$localsnapshots = [];
exec($cmd_zfs_local,$localsnapshots);


$tosync = array_diff($remotesnapshots,$localsnapshots);

if(count($tosync)<1) exit("[i] Nothing to sync. Exiting\n");

$snapshot = end($tosync);

$lastincommon = getLastInCommon($remotesnapshots,$localsnapshots,$snapshot);
if(!$lastincommon)
{
      echo "[i] Don't have any snapshots of that dataset yet. I'll sync initial\n";
      $firstsnap = $remotesnapshots[0];
      $synccmd = "ssh $remoteIP zfs send -w $remoteDataset@$firstsnap | zfs receive -F $localDataset";
      echo "$synccmd\n";
      system($synccmd);
      exit();
}
echo "[i] Syncing from $lastincommon to $snapshot\n";
$synccmd = "ssh $remoteIP zfs send -w -I $remoteDataset@$lastincommon $remoteDataset@$snapshot | zfs receive -F $localDataset";
echo "$synccmd\n";
system($synccmd);


function getLastInCommon($remote,$local,$target)
{
    $incommon = [];
    foreach($remote as $key=>$rsnap)
    {
        foreach($local as $lkey=>$lsnap)
        {
            if($rsnap == $lsnap)
                $incommon[] = $rsnap;

            if($lsnap==$target) break;
        }
    }

    return end($incommon);
}