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csocketsserverclientstrncpy

a question about this strncpy function in socket programming

im currently working on portscanner for my network scanner app with socket in c . i found this code , and i want to understand what's the exact role of strncpy here ! and can someone please expalin this code for my cuz im beginner in network programming and thanks ..

Solution

    1. strncpy((char*)&sa, "", sizeof sa);

      Here author is trying to set 0 to every byte of sa structure.

      As per strncpy

      If the end of the source C string (which is signaled by a null-character) is found before num characters have been copied, destination is padded with zeros until a total of num characters have been written to it.

      If I were you I would do it this way.

      memset(&sa, 0 , sizeof sa);

    1. strncpy((char*)&sa.sin_addr, (char*) host->h_addr, sizeof sa.sin_addr);

      Here Author is trying to copy char *h_addr which holds first host address to s_addr.

      If I were you I would do it this way.

      sa.sin_addr.s_addr = inet_addr(host->h_addr);