09-05-2008
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi everybody,
I'm having some problems wiriting a program in UNIX using the "fork" and "kill" system calls.
I have to create a C program P0, which creates 9 other processes
P1, P2, ..., P9, where P0 is the father of P1, P1 the father of P2, and so on.
All the processes contain an infinite... (0 Replies)
Discussion started by: davewilliams20
0 Replies
2. Programming
Hi
I'm currently working with C on UNIX (HPUX) and need to be able to fork a seperate Java process from within a running C process.
I can run the following code from the command line via a script but am having difficulty getting it to work from within the code.
I am trying to use execl. Is... (4 Replies)
Discussion started by: themezzaman
4 Replies
3. Programming
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
int main()
{
pid_t pID;
int i;
for (i = 0; i < 3; i++)
{
pID = fork ();
if (pID == 0)
{
printf ("Value of i --> %d... (2 Replies)
Discussion started by: kymthasneem
2 Replies
4. UNIX for Advanced & Expert Users
hi,
I thought that when a child shell is forked, it will inherit all the variables of the parent
now in my .cshrc I have
setenv X x
then I do at command line
setenv X y
and X is now y. So far so good!
I then have a very simple script, y.csh
#!/usr/bin/csh
echo X (7 Replies)
Discussion started by: JamesByars
7 Replies
5. UNIX for Dummies Questions & Answers
Hey, first time poster and a new UNIX user here.
My question is regarding the forking process. I logged in to tty1, and typed the command ls -1 and hit enter. How can i tell that the ls -1 command ran in a subshell?
Thanks. (0 Replies)
Discussion started by: Vitamin254
0 Replies
6. Shell Programming and Scripting
I have a bash script that has been used for months here at work for doing an SSH into other machines both Linux and Solaris and running a script on the remote machine. Recently I have started to noticed that things are being left being on the maching doing the SSH.
For example....
tivoli ... (1 Reply)
Discussion started by: LRoberts
1 Replies
7. Shell Programming and Scripting
Hi All,
I have two ksh script. 1st script calls the 2nd script and the second script calls an 'C' program.
I want 1st script to wait until the 'C' program completes.
I cant able to get the process id for the 'C' program (child process) to make the 1st script to wait for the second... (7 Replies)
Discussion started by: sennidurai
7 Replies
8. Shell Programming and Scripting
Hey all, I need to launch a script from within 2 other scripts that can run independently of the two parent scripts... Im having a hard time doing this, if anyone knows how please let me know.
More detail.
ScriptA (bash), ScriptB (ksh), ScriptC (bash)
ScriptA, launches ScriptB
ScirptB,... (7 Replies)
Discussion started by: trey85stang
7 Replies
9. Programming
My question is, how do you fork only the parent processes in unix? For example how would I use the fork function to fork the parent process more than once and leave the children processes alone. This way I do not have children of children. The way I have it set up now it the parent process forks 3... (7 Replies)
Discussion started by: TWhitt24
7 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
LEARN ABOUT REDHAT
pthread_atfork
PTHREAD_ATFORK(3) Library Functions Manual PTHREAD_ATFORK(3)
NAME
pthread_atfork - register handlers to be called at fork(2) time
SYNOPSIS
#include <pthread.h>
int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));
DESCRIPTION
pthread_atfork registers handler functions to be called just before and just after a new process is created with fork(2). The prepare han-
dler will be called from the parent process, just before the new process is created. The parent handler will be called from the parent
process, just before fork(2) returns. The child handler will be called from the child process, just before fork(2) returns.
One or several of the three handlers prepare, parent and child can be given as NULL, meaning that no handler needs to be called at the cor-
responding point.
pthread_atfork can be called several times to install several sets of handlers. At fork(2) time, the prepare handlers are called in LIFO
order (last added with pthread_atfork, first called before fork), while the parent and child handlers are called in FIFO order (first
added, first called).
To understand the purpose of pthread_atfork, recall that fork(2) duplicates the whole memory space, including mutexes in their current
locking state, but only the calling thread: other threads are not running in the child process. The mutexes are not usable after the fork
and must be initialized with pthread_mutex_init in the child process. This is a limitation of the current implementation and might or
might not be present in future versions.
RETURN VALUE
pthread_atfork returns 0 on success and a non-zero error code on error.
ERRORS
ENOMEM insufficient memory available to register the handlers.
AUTHOR
Xavier Leroy <Xavier.Leroy@inria.fr>
SEE ALSO
fork(2), pthread_mutex_lock(3), pthread_mutex_unlock(3).
LinuxThreads PTHREAD_ATFORK(3)