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run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(strlen(pack("H*", "7061636b6167652e786d6c000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000030303030363434003030303137353000303030313735300030303030303231373036370031323030303335343330300030313234353720003000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000757374617220200064657269636b000000000000000000000000000000000000000000000000000064657269636b0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")));
Output for 4.3.0 - 7.1.7
int(512)