Is it possible to cast struct to another?
c, casting, sockets, struct
Solution
This is refered as Type Punning. Here, both structures have the same size, so there is no question of struct size. Although you can cast almost anything to anything, doing it with structures is error-prone.
Problem
Any one could describe how `(struct sockaddr *)&server` works here? Is it possible to cast bigger struct to smaller struct? See these structs: ``` // IPv4 AF_INET sockets: struct sockaddr_in { short sin_family; // e.g. AF_INET, AF_INET6 unsigned short sin_port; // e.g. htons(3490) struct in_addr sin_addr; // see struct in_addr, below char sin_zero[8]; // zero this if you want to }; struct in_addr { unsigned long s_addr; // load with inet_pton() }; struct sockaddr { unsigned short sa_family; // address family, AF_xxx char sa_data[14]; // 14 bytes of protocol address }; ``` This is the main program: ``` int main(int argc , char *argv[]) { int socket_desc; struct sockaddr_in server; //Create socket socket_desc = socket(AF_INET , SOCK_STREAM , 0); if (socket_desc == -1) { printf("Could not create socket"); } server.sin_addr.s_addr = inet_addr("74.125.235.20"); server.sin_family = AF_INET; server.sin_port = htons( 80 ); //Connect to remote server if (connect(socket_desc , (struct sockaddr *)&server , sizeof(server)) < 0) { puts("connect error"); return 1; } puts("Connected"); return 0; } ```