Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!sunic!news.funet.fi!kannel!Hannu.Martikka
From: Hannu.Martikka@lut.fi (Hannu Martikka)
Newsgroups: comp.sys.apollo
Subject: Re: Problem with pipe/fork
Message-ID: <HANNU.MARTIKKA.91Apr17114721@kannel.lut.fi>
Date: 17 Apr 91 09:47:21 GMT
References: <1991Apr16.150907.2417@jsp.umontreal.ca>
Sender: goodgulf@lut.fi (Hannu Martikka)
Organization: Lappeenranta University of Technology, Finland
Lines: 44
In-Reply-To: gaumondp@JSP.UMontreal.CA's message of 16 Apr 91 15:09:07 GMT
Disclaimer: All my opions are mine. (usually)

>>>>> On 16 Apr 91 15:09:07 GMT, gaumondp@JSP.UMontreal.CA (Gaumond Pierre) said:

.> character is transfered to the standard output. The processes seem
.> to wait for something... for what? EOF?
I think you haveto close all other pipe ends too. (stdin/stdout)
Here I have simple program in witch child does who and parent does
sort ie. who | sort.
-- clip ----------------------------------------------------------
#include <stdio.h>
#include <sys/types.h>
main(argc,argv)
     int argc;
     char **argv;
{
  int pid;
  int pipeline[2];

  pipe (pipeline);
  if ((pid=fork())== -1) { perror("fork"); exit(1); }
  if (pid != 0) 
    { /* father */
      close(0); /* Haveto close stdin */
      dup (pipeline[0]);
      execlp("sort","sort",0);
    } 
  else 
    { /* child */
      close(1); /* Haveto close stdout */
      dup(pipeline[1]);
      execlp("who","who",0);
    }
}
	  

--

Regards from Goodi
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