gcc - Help understanding -> operator in C -


possible duplicate:
arrow operator (->) usage in c

i new c, , trying understand function (see below).

the main parts confusing me are:

sp->s_port = htons(sp->s_port);

and

p = sp->s_port;

i'm not sure understand -> operator.

here whole function... hostbufferlength set 1024 (not sure if matters)

int gi_get_port (char *serv, char *prot) /* obtain port named service */ {   int p, s;    /* data resolving service name socket description. */   struct servent *sp = null;    char            gsbn_servbuf[hostbufferlength] = {0};                         struct servent  gsbn_sp;                                                      struct servent *gsbn_serv_result;                                             int             gsbn_s = 0;                                                   gsbn_s = getservbyname_r(serv,                                                                 prot,                                                                     &gsbn_sp,                                                                     gsbn_servbuf,                                                                 sizeof(gsbn_servbuf),                                                         &gsbn_serv_result);                                       sp = gsbn_serv_result;                                                        sp->s_port = htons(sp->s_port);                                               if (sp && socket_debug) {                                                        printf("%s get_service_by_name - service: %s port: %d protocol: %s\n",                   get_timestamp(), sp->s_name, sp->s_port, sp->s_proto);                  }                                                                             if (sp == null) {                                                                fprintf(stderr, "%s get_service_by_name - service %s not found.\n",                   get_timestamp(), serv);                                         }    if (sp != null) {     p = sp->s_port;   } else {     p = -1;   };    return p; }

the -> operator shorthand dereferencing pointer , accessing member of structure points to.

foo->x

can done in place of

(*foo).x


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