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Full Discussion: Pipes connecting 3 processes in a "circle"
Top Forums Programming Pipes connecting 3 processes in a "circle" Post 302500892 by tfarmer4 on Wednesday 2nd of March 2011 12:56:02 AM
Old 03-02-2011
Network Pipes connecting 3 processes in a "circle"
I am trying to get a better understanding of pipes and processes. I have code in which I link 3 processes A,B,C. I have A->B->C but how would I go about getting C->A?

Here is my code:

Code:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
main()
{
pid_t A, B, C;
int fd[2];
int fd2[2];

if (pipe(fd) == -1)
{
    perror("pipe");
    exit(1);
}
B = fork();
if (B == -1)
{
    perror("fork");
    exit(2);
}
if (B == 0)
{
    if (pipe(fd2) == -1)
    {
        perror("pipe");
        exit(11);
    }
    C=fork();
    if(C == -1)
    {
        perror("fork 2");
        exit(22);
    }
    if (C == 0)
    {
        //i am C
        //do some stuff
    }
    else
    {
        //i am B
        //do some stuff
    }
}
else
{
    //i am A
    //do some stuff
}

 

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LEARN ABOUT OSF1

procset

procset(4)						     Kernel Interfaces Manual							procset(4)

NAME

       procset.h - Send a signal to one or more processes

SYNOPSIS

       typedef struct procset {
	       idop_t  *p_op;
	       idtype_t p_lidtype;
	       id_t	p_lid;
	       idtype_t p_ridtype;
	       id_t	p_rid; } procset_t;

DESCRIPTION

       The  contents of the <procset.h> structure define a set of target processes based on logical operations performed on the two sets of poten-
       tial target processes indicated by the two pairs of id + type parameters, which designate "left" and "right" groups of processes.  The log-
       ical operations supported are the union, intersection, difference, and exclusive OR of the left and right groups.

       The  p_lid  and p_lidtype members define one set of potential target processes, the "left" set.	The p_rid and p_ridtype members define the
       "right" set of potential target processes.  These parameters work together to select the target process or processes.

       The value of p_op is used to combine these two groups into the final group of actual target processes: Specifies that the target  group	of
       processes  consist  of  the remaining processes in the left set that are not common to the right set.  Specifies that the target group con-
       sists of those processes that are in both sets.	Specifies that the target group consists of those processes that are in either set, or	in
       both sets.  Specifies that the target group consists of those processes that are in either set, but not in both sets.

RELATED INFORMATION

       Functions: priocntlset(2), sigsend(2).

       Files: signal.h(4).  delim off

																	procset(4)
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