OpenSC API Reference sc_lock 3 opensc sc_lock Lock a card for exclusive use Synopsis #include <opensc.h> int sc_lock(struct sc_card *card); Description This function locks the card against modification from other threads or processes. The function may be called several times; a counter will be increased, and the card will be unlocked only when this counter reaches zero. Return value Returns 0 on success, or a negative value in case of error.