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Full Discussion: Unix Piping Problem
Homework and Emergencies Homework & Coursework Questions Unix Piping Problem Post 302705847 by itsjimmy91 on Tuesday 25th of September 2012 03:14:15 PM
Old 09-25-2012
Hey man, thanks a lot for the replies. Sorry about the code thing. I have made a few adjustments and I think I am really close. My only problem now is that the program is not actually displaying the information in reverse. Is my reverse command not getting hit?

Code:
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

int main() {
  int pipefd[2];
  int pid1 = 0, pid2 = 0;
  char *lsArg[2] = {"ls", 0};
  char *rArg[2] = {"-r", 0};
  pipe(pipefd);

  printf("Welcome, friend!\n");
  pid1 = fork();
  if(pid1 == 0) {
    close(piped[0]);
    dup2(pipefd[1], 1);
    execv("/bin/ls", lsArg);
  }

  pid2 = fork();
  if(pid2 == 0) {
    close(piped[0]);
    dup2(pipefd[0], 0);
    execv("/bin/ls", rArg);
  }
  else {
    close(pipefd[0]);
    close(pipefd[1]);
    waitpid(pid2, NULL, 0);
  }
}

 

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LEARN ABOUT V7

macutil

MACUTIL(1)						      General Commands Manual							MACUTIL(1)

NAME

       macutil - A package that deals with MacIntosh files on a Unix system

DESCRIPTION

       macutil	is  a package that contains a number of utilities that deal with MacIntosh files on a Unix system.  It contains the following pro-
       grams:

       binhex Convert files to BinHex 4.0 compatible hexified form.

       frommac
	      Receives files from the MacIntosh on the Unix system.

       hexbin Convert hexified files to their MacIntosh format.

       macsave
	      Save a series of files from a MacBinary stream as individual files.

       macstream
	      Combine a series of files to a MacBinary stream.

       macunpack
	      Unpack a MacIntosh archive into its constituents.

       tomac  Transmits files from the Unix system to a MacIntosh.

BUGS

       This manual page is hopelessly incomplete!

SEE ALSO

       binhex(1), frommac(1), hexbin(1), macsave(1), macstream(1), macunpack(1), tomac(1)

AUTHOR

       Dik T. Winter, CWI, Amsterdam, The Netherlands (dik@cwi.nl)

3rd Berkeley Distribution					 October 22, 1992							MACUTIL(1)
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