Scans a, starting with bit start, towards more significant bits, until the first clear bit is found. Returns the index of the found bit. The index starts from 0.
<?php
// "0" bit is found at position 3. index starts at 0
$s1 = gmp_init("10111", 2);
echo gmp_scan0($s1, 0) . "\n";
// "0" bit is found at position 7. index starts at 5
$s2 = gmp_init("101110000", 2);
echo gmp_scan0($s2, 5) . "\n";
?>
The printout of the above program will be:
3
7