in reply to Determinine Protocol In inetd.

If I recall, you can specify parameters in the inetd.conf, so just call the program two different ways by passing a parameter.

-- Randal L. Schwartz, Perl hacker

Replies are listed 'Best First'.
Re: Re: Determinine Protocol In inetd.
by traveler (Parson) on Apr 28, 2001 at 19:56 UTC
    This is probably the easiest approach. Another is to try to get the TCP option TCP_MAXSEG and if it fails, it is a UDP socket.

    You can, however, get the info you want if you are using Linux. I don't know about other OSs as I don't have any other development platforms here. If you do a 

    getsockopt SOCK, SOL_SOCKET, SO_TYPE;

    [download]
    it will (should?) return SOCK_STREAM for stream (TCP) sockets and SOCK_DGRAM for datagram (UDP) sockets. This looks like it works from C, but on my perl5.005003 it seems to have a problem. Maybe it's my system...

    HTH, traveler

[reply]
[d/l]
      After investigating it, you are correct. That would be the best way to get it. However, it is disabled in most of the perl versions I have looked at. Thanks for the work. I'll have to continue recording information the way that I was. 
      perl -we 'use Socket; Socket::getsockopt()'
Your vendor has not defined Socket macro getsockopt, used at -e line 1

      [download]
      my @a=qw(random brilliant braindead); print $a[rand(@a)];
[reply]
[d/l]
Re: Re: Determinine Protocol In inetd.
by Rhandom (Curate) on Apr 28, 2001 at 19:16 UTC
    I mentioned this as a possibility. If I have to I will. But I would rather that the code could determine it on its own.

    Even without passing parameters I could write a dummy script:
    #!/usr/bin/perl
exec "MyRealProg.pl --proto=udp"

    [download]
    Course, this would be a double exec.

    Is there any way to do it (suppose I wasn't in inetd and I was passed some fileno's of sockets to connect to -- is there a way to determine?)

    my @a=qw(random brilliant braindead); print $a[rand(@a)];
[reply]
[d/l]
      Looks like getsockopt can be used with an SO_TYPE subcommand to get the type such as SOCK_STREAM. I don't have working code, but something along that line should be useful.

      -- Randal L. Schwartz, Perl hacker

[reply]
      But I would rather that the code could determine it on its own.

      identd has the protocol in hand, yet you prefer to drop this knowledge on the floor and then rederive it downstream. Curiousity about how you might be able to derive the discarded prototype info is one thing, but from a pragmatic point of view, this is wasteful a approach.

[reply]

In Section Seekers of Perl Wisdom