Re: fork() and socketpair()

[Steve Baker <sjbaker1@airmail.net>]

Francesco Orsenigo wrote:
> 
> My program forks into two separate processes, and i must connect them with a
> pipe wich i must be able to use with send() and recv().
> socketpair is perfect (i socketpair() and then fork()) but it seems not very
> portable.
> The alternative would be fork() and then link the two processes with standard
> socket()/connect()/listen() calls.
> 
> I thought about using pipe(), but it is not full-duplex and i don't know if
> it is safe to use with send() and recv().

Well, you can use TWO calls to 'pipe()' (one for each direction) and use
read/write instead of send/recv().

Pipes and sockets are entirely different mechanisms - pipes use file-system
calls (hence read/write) and sockets use network-system calls (hence send/recv).

socketpair is somewhat portable because it conforms to the BSD4.4 spec.
The man page says:

   CONFORMING TO
       4.4BSD (the socketpair function call appeared in  4.2BSD).
       Generally  portable  to/from  non-BSD  systems  supporting
       clones of the BSD socket layer (including System  V  vari­
       ants).

You might also consider "named pipes" (aka FIFO's) which can be opened
just like files.

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