Re: [gnugo-devel] pipe

[Dave Denholm]

address@hidden (Wolfgang Manner) writes:

> who knows about pipes ?
>
> according to what i read
>    pipe(PIPEDES)
>
> should give
>
>    If successful, two file descriptors are stored in PIPEDES;
>    bytes written on PIPEDES[1] can be read from PIPEDES[0].
>    Returns 0 if successful, -1 if not.  */
>

Sounds about right - definitely works for me on solaris

NAME
     pipe - create an interprocess channel

SYNOPSIS
     #include <unistd.h>

     int pipe(int fildes[2]);

DESCRIPTION
     The pipe() function creates an I/O mechanism called  a  pipe
     and  returns  two file descriptors, fildes[0] and fildes[1].


In fact on solaris, you get a bidirectional pipe. Traditionally,
you can only write to one of the fd's and read from the other.


>  but when i do it i get
>
> PIPEDES[0] = 4
> PIPEDES[1]   some address
>
> and it returns 3
>
> do i have a old version ? i have noticed that i can include
> unistd.h
> or not, it doesnt make any difference
>

Getting 3 and 4 as the two fd's would seem reasonable - perhaps
there's a prototype problem ?

eg

$ truss -f sh -c 'echo x | cat'
...
24110:  pipe()                                          = 3 [4]
...


dd
-- 
Dave Denholm              <address@hidden>       http://www.esmertec.com