c - Why socklent_t * is used in accept() in socket programming? -


in c socket programming accept() declaration looks like:

int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen);

i can understand uses of sockfd, struct sockaddr *addr.

but why have pass address of length of socket, have been socklen_t. because if accept() function needs length can socklen_t. why protype of function declared in such way?

so reason behind using socklen_t * type?

in code that's agnostic address/protocol family of socket it's accepting from, may using generic sockaddr_storage structure hold result. initial value of pointed-to socklen_t size of storage; value after accept returns actual size of resulting peer address. also, address/protocol families af_unix have variable length addresses, if know type may not know size.


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