(PECL apc >= 3.0.13)
apc_add — Cache a new variable in the data store
Caches a variable in the data store, only if it's not already stored.
Note: Unlike many other mechanisms in PHP, variables stored using apc_add() will persist between requests (until the value is removed from the cache).
key
       Store the variable using this name. keys are
       cache-unique, so attempting to use apc_add() to
       store data with a key that already exists will not overwrite the
       existing data, and will instead return FALSE. (This is the only
       difference between apc_add() and
       apc_store().)
      
varThe variable to store
ttl
       Time To Live; store var in the cache for
       ttl seconds. After the
       ttl has passed, the stored variable will be
       expunged from the cache (on the next request). If no ttl
       is supplied (or if the ttl is
       0), the value will persist until it is removed from
       the cache manually, or otherwise fails to exist in the cache (clear,
       restart, etc.).
      
valuesNames in key, variables in value.
Returns TRUE if something has effectively been added into the cache, FALSE otherwise. Second syntax returns array with error keys.
Example #1 A apc_add() example
<?php
$bar = 'BAR';
apc_add('foo', $bar);
var_dump(apc_fetch('foo'));
echo "\n";
$bar = 'NEVER GETS SET';
apc_add('foo', $bar);
var_dump(apc_fetch('foo'));
echo "\n";
?>
The above example will output:
string(3) "BAR" string(3) "BAR"