Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Creating Multiple Processes
Top Forums Programming Creating Multiple Processes Post 302392536 by Corona688 on Thursday 4th of February 2010 05:32:09 PM
Old 02-04-2010
fork() returns the PID of the child process to the parent, just store its value. Or if you need the value in the child, get it with getpid().

Is the fork at the top of the loop just to run two processes? If so, keep in mind you'll end up with two waiters, too! I usually encapsulate each fork in code like:

Code:
pid_t pid=fork();
if(pid < 0)
{
  // error
}
else if(pid == 0)
{
  // child code
  exit(0); // to prevent it executing code below.  after all what if exec fails?
}
else if(pid > 0)
{
  // parent code.
}

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Shell script creating too many processes.

I have a shell script that I am running every 60 seconds, but it is creating this process to the point that it is causing the server to perfrom poorly. Below is my script, what can I change to prevent this? while true do java -classpath .....( all my classes here) >/dev/null 2>&1 ... (3 Replies)
Discussion started by: Miller_K
3 Replies

2. Shell Programming and Scripting

Doubt about multiple processes

Suppose that I am performing some operation on an sql database. Lets say process of Searching and then if a value is found, updating it... Now, when I have some millions of records on which the operation has to be performed... Does it help to spawn multiple processes each executing the same... (9 Replies)
Discussion started by: Legend986
9 Replies

3. Shell Programming and Scripting

multiple processes overlap

Hello I've got a script that creates multiple processes, in ksh, to bcp out 6 tables at a time. In the script, we write messages to the log to show our progress; most of the time, the log messages are nice and neat with one per line, like they should be. But every once in awhile, at random, the... (2 Replies)
Discussion started by: stonemonolith
2 Replies

4. UNIX for Dummies Questions & Answers

Running multiple processes in Linux

Hi guys, I want to run the multiple scripts at the same time using a ksh script. For example, I have three scripts to run: a.ksh, b.ksh and c.ksh How to start the above 3 scripts simultaneously and then on the completion of the above scripts I have other tasks to schedule. Thanks Gary (6 Replies)
Discussion started by: abcabc1103
6 Replies

5. Shell Programming and Scripting

Creating a pipe using parent and child processes

Hello, I am trying to create a pipe that will direct stdout to in side of the pipe, and stdin to the out side of the pipe - I created two child processes to handle this. However, my pipe doesn't seem to be working correctly. Did I use execv() correctly? Command1 and command2 represent the two... (3 Replies)
Discussion started by: jre247
3 Replies

6. Shell Programming and Scripting

kill multiple processes by name

Want to kill multiple processes by name. for the example below, I want to kill all 'proxy-stagerd_copy' processes. I tried this but didn't work: >> ps -ef|grep proxy_copy root 991 986 0 14:45:34 ? 0:04 proxy-stagerd root 1003 991 0 14:45:49 ? 0:01... (2 Replies)
Discussion started by: catalinawinemxr
2 Replies

7. Solaris

Multiple hanged FTP processes

Hello people, I got one problem with a script. I have a script which runs every five mins and in the script an ftp process is invoked which sends files to a particular location. The problem is that the ftp process hangs every now and then which causes the whole script to hang. As the... (4 Replies)
Discussion started by: m_usmanayub
4 Replies

8. Programming

Creating more processes with fork()

Hello people I need help How to make ONE process to create MORE (not one) processes with fork(). I tried several codes but do not work. Thanks (8 Replies)
Discussion started by: nekoj
8 Replies

9. Shell Programming and Scripting

need help ps -e on multiple processes

:)Hi there, I am new to scripting and wanted to see if someone can show me how to grep on multiple processes and send the output to a file in /home/mydir/output. I am aware of ps -ef | grep on 1 process but need help looking up multiple processes, can you use this command ps -elf | grep |pid1... (4 Replies)
Discussion started by: abbya
4 Replies

10. Shell Programming and Scripting

SPAWN Multiple Processes in Unix

Hi, I have three files in my IN directory.Each file should be copied 25 times using for loop.Each file processing should run in parallel?How to spawn multiple processes in unix?Any help would be appreciated. Thanks, Liyakath (7 Replies)
Discussion started by: liyakathali
7 Replies

LEARN ABOUT PHP

pcntl_fork

PCNTL_FORK(3)								 1							     PCNTL_FORK(3)

pcntl_fork - Forks the currently running process

SYNOPSIS

       int pcntl_fork (void  )

DESCRIPTION

	The pcntl_fork(3) function creates a child process that differs from the parent process only in its PID and PPID. Please see your system's
       fork(2) man page for specific details as to how fork works on your system.

RETURN VALUES

	On success, the PID of the child process is returned in the parent's thread of execution, and a 0 is returned in  the  child's	thread	of
       execution. On failure, a -1 will be returned in the parent's context, no child process will be created, and a PHP error is raised.

EXAMPLES

       Example #1

	      pcntl_fork(3) example

	      <?php

	      $pid = pcntl_fork();
	      if ($pid == -1) {
		   die('could not fork');
	      } else if ($pid) {
		   // we are the parent
		   pcntl_wait($status); //Protect against Zombie children
	      } else {
		   // we are the child
	      }

	      ?>

SEE ALSO

       pcntl_waitpid(3), pcntl_signal(3), setproctitle(3).

PHP Documentation Group 													     PCNTL_FORK(3)
All times are GMT -4. The time now is 01:25 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy