04-23-2008
I'll post in my website ASAP, but isn't the pipe used for this?
I mean, if I write on the pipe, shouldn't the parent be able to read it normally?
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I don't follow what these are...
this is what my text says...
"When a process is started, a duplicate of that process is created. This new process is called the child and the process that created it is called the parent. The child process then replaces the copy for the code the parent... (1 Reply)
Discussion started by: xyyz
1 Replies
2. Programming
Hi all, i need to execute a program from within my c++ code. This is no problem. system(), fork(), execxy(). But now i want to able to execute the program as another user as the parent process.
The whole thing is on solaris. I should be possible for both, users with no shell and no password... (1 Reply)
Discussion started by: heck
1 Replies
3. Programming
Hello,
How many child processes are actually created when running this code ?
#include <signal.h>
#include <stdio.h>
int main () {
int i ;
setpgrp () ;
for (i = 0; i < 10; i++) {
if (fork () == 0) {
if ( i & 1 ) setpgrp () ;
printf ("Child id: %2d, group: %2d\n", getpid(),... (0 Replies)
Discussion started by: green_dot
0 Replies
4. Shell Programming and Scripting
Hello,
How many child processes are actually created when running this code ?
#include <signal.h>
#include <stdio.h>
int main () {
int i ;
setpgrp () ;
for (i = 0; i < 10; i++) {
if (fork () == 0) {
if ( i & 1 ) setpgrp () ;
printf ("Child id: %2d, group: %2d\n",... (1 Reply)
Discussion started by: green_dot
1 Replies
5. UNIX for Advanced & Expert Users
Hi, as I understand fork(), it makes a copy of the parent which becomes a child. But is there anyway to make three children for that one parent. So in other words, if I look up the getppid() of the children, I want them to have the same value??
Thanks in advance to any help! (1 Reply)
Discussion started by: MS_CC
1 Replies
6. UNIX for Advanced & Expert Users
Hi all,
I am writing a script which calls other third party scripts that perform numerous actions. I have no control over these scripts.
My problem is, one of these scripts seems to execute and do what it is meant to do, but my calling / parent script always exits at that point. I need to... (4 Replies)
Discussion started by: mark007
4 Replies
7. Programming
i used function fork().
so i made two process.
parent process accepted socket fd and writing to shared memory.
then now. how can child process share parent's socket fd?
is this possible?
Thanks in advance (1 Reply)
Discussion started by: andrew.paul
1 Replies
8. Homework & Coursework Questions
1. The problem statement, all variables and given/known data:
I need to make an program that in a loop creates one parent and five children with fork(). The problem i'm trying to solve is how to delete the parent and child of the childīs process.
2. Relevant commands, code, scripts,... (0 Replies)
Discussion started by: WhiteFace
0 Replies
9. Programming
Hi friends,
I have a small question regarding unix system call fork, I hope you will solve my problem. Here is the small program
$ cat fork1.c
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
int main()
{
int pid;
int x = 0;
x = x + 1;
pid = fork();
if(pid < 0)
{... (2 Replies)
Discussion started by: gabam
2 Replies
10. Shell Programming and Scripting
Hi everyone
i am very new to linux , working on bash shell.
I am trying to solve the given problem
1. Create a process and then create children using fork
2. Check the Status of the application for successful running.
3. Kill all the process(threads) except parent and first child... (2 Replies)
Discussion started by: vizz_k
2 Replies
PIPE(2) BSD System Calls Manual PIPE(2)
NAME
pipe -- create descriptor pair for interprocess communication
SYNOPSIS
#include <unistd.h>
int
pipe(int fildes[2]);
DESCRIPTION
The pipe() function creates a pipe (an object that allows unidirectional data flow) and allocates a pair of file descriptors. The first
descriptor connects to the read end of the pipe; the second connects to the write end.
Data written to fildes[1] appears on (i.e., can be read from) fildes[0]. This allows the output of one program to be sent to another pro-
gram: the source's standard output is set up to be the write end of the pipe; the sink's standard input is set up to be the read end of the
pipe. The pipe itself persists until all of its associated descriptors are closed.
A pipe whose read or write end has been closed is considered widowed. Writing on such a pipe causes the writing process to receive a SIGPIPE
signal. Widowing a pipe is the only way to deliver end-of-file to a reader: after the reader consumes any buffered data, reading a widowed
pipe returns a zero count.
The generation of the SIGPIPE signal can be suppressed using the F_SETNOSIGPIPE fcntl command.
RETURN VALUES
On successful creation of the pipe, zero is returned. Otherwise, a value of -1 is returned and the variable errno set to indicate the error.
ERRORS
The pipe() call will fail if:
[EFAULT] The fildes buffer is in an invalid area of the process's address space.
[EMFILE] Too many descriptors are active.
[ENFILE] The system file table is full.
SEE ALSO
sh(1), fork(2), read(2), socketpair(2), fcntl(2), write(2)
HISTORY
A pipe() function call appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution February 17, 2011 4th Berkeley Distribution