Re: getservbyport
Albert Cahalan (albert@ccs.neu.edu)
Wed, 15 May 1996 18:28:12 -0400 (EDT)
>> I've got the question: why this produces shit! ?
>>
>> #include <stdio.h>
>> #include <netdb.h>
>>
>> main() {
>> struct servent *serv;
>> if ((serv = getservbyport(23, "tcp")) == NULL) {
>> printf("shit!\n");
>> } else {
>> printf("name: %s\n", serv->s_name);
>> }
>> }
>
> Because you need to put the port number in network format.
> Replace your query line with:
>
> if ((serv = getservbyport(htons(23), "tcp")) == NULL) {
>
> No, it doesn't make it clear in the man page!
I suppose it is _way_ to late to fix, but I have to wonder why
getservbyport() doesn't do the conversion itself. A library
running on a little-endian machine should not require the
programmer to mess with htons() at all.
It almost looks like something a vendor designed to make it
difficult to write portable programs. (If you only have a
Sun, that's where you test your program for bugs.)