my code is very simple:
int pid, status;
printf("parent process id=%d, to call fork
",getpid());
if(pid=fork()<0)
[Code].....
but everytime I can only get two fork return pid=0. In parent process, the pid returned by fork() should be >0 and equal to the child process id.
Code:
int main()
{
int pi;
int i=10;
pid=fork();
[code]....
Q 1. The value of the variable pid returned by the fork() function will be greater than 0 in the parent process and equal to zero in the child process? but during forking, there values are exactly copied so what's went wrong here?
Q 2. "changes to the variable in one process is not reflected in the other process" why it is so? >> Even if we have variable i declared as a pointer or a global it wont make a difference.
Code:
int main()
{
int i, pid;
i=10;
printf("before fork i is %d
[code]....
Q. Through this program it is clear that both process is using the data from the same location, so where's the original value is residing when the child process is in execution.?
Code:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
[code]....
Description of what the code does or what i intended to do:
1. Created a child process from parent process using 'fork()'
2. Sent a signal 'SIGALRM' from child process to parent process using 'sigqueue' function.
(The Third parameter of 'siqueue' function contains the message (message msg) which the child process wants to send to the parent process.'msg' is a stucture instance containing a) pid of child and b) string) 5. Print the 'msg' sent by child process inside the signal handler function 'sig_action_function' of the parent process I am getting some junk value when this line is executed
Code:
printf("%d
",msg->cpid);
I expected to get the pid of child process, which the child process sent to parent process through the signal.
How do you find the parent process of zombie processes?
When the child process is something where the parent is not entirely obvious...
Is there some way to list processes in tree format or something?
I've a script that forks to another script.
The problem is that the child will not return to main process.
Main script "fork.sh"
Code:
The child process "smb_fork.sh"
Code:
when running it from the terminal "sh -x ./foork.sh"
Code:
My goal is via cron connect to ~100 remote winXP computers and download a single file. There fore I like to fork the process.
trying to fork multiple child but the program does not go as i want...
My code :
Code:
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
[code].....
I would like to run versions of Mozilla Firefox 3.6.5+ as a single process, just as it was in versions 3.6.3 and prior. The reason is that, on Linux, I am running within proxychains - which doesn't bind to forked processes. Because the plugins in versions 3.6.5+ run in a forked process I can't use proxychains to redirect Flash streams. Is there a setting in modern versions of Firefox that allow me to run plugins in the main process?
View 1 Replies View RelatedI want to kill parent process after "fork()" method. but if I kill parent process with "exit(0)" method, main() thread is terminated as well so child prosess doesn't work anymore. Is there any way to kill only parent process without affecting to child process?
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
[code]....
Resolved before asked: cat /proc/1111/status | grep PPid
View 2 Replies View RelatedWhat happens to a child process that dies and has no parent process to wait for it and what's bad about this?
View 2 Replies View RelatedI have a script that calls other scripts/commands which may or may not spawn other process. From my understanding, when I do a ps -ef, the highest numbered process ID is supposed to be the parent ID of all the other related child processes, is this correct? In most or all circumstances, I do a ps -ef | grep <processid> of my script and anything that spawns off that process IDs I assumed are the child processes of my script. If I want to terminate my script and all other child processes, then I kill the parent ID which is the highest numbered PID and this will subsequently kill all other child process IDs, is this correct?
Now, my question is whether there is any quick way of showing what are the child processes of a parent ID instead of what am currently doing now which is visually checking which one is the parent ID and "assuming" that the highest numbered PID is the parent ID of all the other processes. Below is a sample output of running ps -ef | grep exp | grep -v grep. I assume from the output below that the parent process/ID is PID 11322, is that correct?
Code:
oracle 11154 11153 0 21:20 ? 00:00:00 /bin/sh -c (. ~oracle/.profile; /bin/ksh /usr/local/oracle/scripts/expdp_o
oracle 11155 11154 0 21:20 ? 00:00:00 /bin/sh -c (. ~oracle/.profile; /bin/ksh /usr/local/oracle/scripts/expdp_o
oracle 11190 11155 0 21:20 ? 00:00:00 /bin/ksh /usr/local/oracle/scripts/expdp_schema.ksh dev01
oracle 11322 11190 0 21:20 ? 00:00:00 expdp
I am facing an issue where the process starts hanging. When I closely look at the logs I come to know that some of the child processes that are forked by the parent process are not finished.
1) Is it possible that the child processes that are not finished occupy the socket memory of the parent process and ultimately a point is reached where no socket memory is available to fork new child processes.
2) What is the standard limit of socket memory in linux?
3) What is the fate of such child processes (as I have mentioned above)?
4) How to debug such cases so that the exact problematic area is identified?
well i have just started with shell scripting...how to find all child processes of a parent process given to script as argument.
View 10 Replies View Relatedeach time my linux is booting, it check something like eth0 and something else. but there is something i write below that fail... Code: could not receive return value from daemon proccess?
View 3 Replies View RelatedI have a script in /etc/rc.d/init.d named foo. I want to start/stop/restart my process as follows:$ foo start But I do not see the [OK] message once it starts. There is no shell prompt returned either. It seems that my own process is the problem. The executable that foo calls is built from this sample code:
int main()
{
do {
printf("Hello world
");
sleep(1);
} while (1);
}
Do I have to return some kind of signal handle for this to work?
Consider the following code:
Code:
int main()
{
int i=0;
pid_t pid;
for(i=0;i<2;i++)
[code]....
I get the following output:
Parent: chid_pid=4356 i=0 parent's pid=4355
This is child 4356 i=0
This is child 4357 i=1
[code]....
I can observe instead of two children(as I expect) processes there are three. This is because child process 4356 creates its own child. Why all the messages of the type "This is child X i=Y" are concentrated one under another? How exactly fork works? Is affected by the fact that I have a dual-core processor?
i got basic knowledge about creating a single child from a parent using fork(). But when it comes into creating multiple children, i am simply stuck. I am trying to create two processes from a parent and it would wait for both two processes to finish. my attempt is as below
[Code]....
I know that fork() copies the address space of the calling process. Say, however, i have a linked list allocated. Will the list be copied over to the child process's space? If so, i would have to free them in the child process as well as the parent process, correct? Or will the variables be copied but not be pointing to any valid address? Or would it just kind of not do anything?example:
Code:
struct ll_ex {
struct ll_ex * next;
[code]....
I am trying to kill child process without killing the parent and seem to be having issues doing so. I have tried quite a few different commands and the end result is either killing all of them including the parent or not killing them at all.
View 1 Replies View RelatedI am going to create a parent process and fork a child process from it. I want to write a code in such a way that whenever my child process end it must indicate that the child process is terminated by a signal or not. This code must be written in the parent process block.
View 6 Replies View RelatedWhat i am trying to do is i want to add numbers from 1 to 100. but that too using multiprocessing. So i made a c programme and using fork() command made two child processes. Now in one child process i am adding from 1 to 50. and in another i am adding 51 to 100. and then in the parent process adding the two results to get the final one. Now the result from the two function i am getting correctly. But after the wait() call the value returned is lost : See the programme below for reference
# include<stdio.h>
# include<unistd.h>
# include<sys/wait.h>
# include<stdlib.h>
[code].....
I have a transparent proxy Squid-3.0 on Slackware 12.2. I used cron to restart squid every day at 7:30 AM (just /path.to.squid/squid -k kill && /path.to.squid/squid) Some days ago I saw in /var/log/messages that Squid was killed but haven't started. I started it manually and everything was OK. But today everything repeated. And the log file is interesting. I tried to find about it on http://squid-cache.org/ but al in vain. This is from /var/log/messages :
Code:
May 24 07:30:02 konura squid[17188]: Squid Parent: child process 17199 exited due to signal 9
May 24 07:30:02 konura squid[19038]: Squid Parent: child process 19040 started
May 24 07:30:03 konura squid[19038]: Squid Parent: child process 19040 exited with status 1
May 24 07:30:06 konura squid[19038]: Squid Parent: child process 19045 started
[code]....
I need to say that I haven't edited the config file for a long time, but this problem started to happen. ADDED, Solved: I'm not sure, but maybe I found the decision. I deleted about 400 mb of Sarg logs from /var partition. And now squid runs well. Besides, before deleting old logs, 'crontab -e' and 'pkgtool' didn't work And the system wrote me that it's no space left on device. At the same time, 'df -h' showed me that all partitions had enough free space. Seems strange, but that's it. After deleting old proxy statistics, generated by Sarg (this is about 400 mb) 1)squid runs OK and 2)there are no more that annoying messages about abscence of free space.
I am using pthread_create system call to create a thread. However pthread_create does not return the PID ( process ID). Is there any quick way to fınd the PID of the created thread.
View 1 Replies View RelatedI am want get next information: Get process statistics from kernel and return them buf as
Quote:
number of processes : ticks_user : ticks_system : ticks_interrupt : cpuseconds : procsizes : resident segment sizes I am find some this information in /proc/[pid]/stat, but there are is not data about ticks system, ticks_interrupt, cpusecond. Where I am can find it information???
I am write on C, better if it will file witch information, and not programm.
I have a doubt about signals in C programming. I have done this little program to explain it. It creates a child process with fork and, when the child ends, receives the SIGCHLD signal and wait for its termination.Ok, quite easy, BUT when I execute this code the SIGCHLD signal is received twice, first as an error (returns -1) and the second one to finish the child process.I don't understand the meaning of the first received signal. Why is it generated? Is the code wrong? (if you add the SIGINT and press Ctrl+C during the execution it also receives two signals instead of one)
Code: #include <stdio.h>
#include <unistd.h>
#include <string.h>
[code]....
I keep getting a segfault in compiz. I've tried everything! This is from a fresh install without and accelerated drivers (I have ATI)
Quote:
Code:
**Switching to Compiz window management**
/usr/local/bin/compiz-indicator:99: GtkWarning: Can't set a parent on widget which has a parent
menu.append(kill)
/usr/local/bin/compiz-indicator:100: GtkWarning: Can't set a parent on widget which has a parent
menu.append(start)
[code]....
Is it possible to have an Expect script spawn an SSH session, log in, then go into interactive mode and give control of the SSH session to a Bash script? Here's a simplified example of the script so far:
Code:
#!/bin/bash
expect -c "
[code]....
1) Write a C program using the fork() system call that that generates the Fibonacci sequence in the child process. The number of the sequence will be provided in the command line. For example, if 5 is provided, the first five numbers in the Fibonacci sequence will be output by the child process. Because the parent and child processes have their own copies of the data, it will be necessary for the child to output the sequence. Have the parent invoke the wait() call to wait for the child process to complete before exiting the program. Perform necessary error checking to ensure that a non-negative number is passed on the command line.
2) Repeat the preceding exercise, this time using the CreateProcess () in the Win32 API. In this instance, you will need to specify a separate program to be invoked from CreateProcess(). It is this separate program that will run as a child process outputting the Fibonacci sequence. Perform necessary error checking to ensure that a non-negative number is passed on the command line.i have done with Fibonacci sequence .but i dont know how to include tht fork() function and win32 api .any one can help to finish?
I am continuously getting fork: resources temporarily unavailable even when I am typing ls command.
View 1 Replies View RelatedI am working on a project where I need to use the C language to generate a tree of processes. I understand how fork() works but I cant seem to get fork() to create two children from one parent and then have the two children create two more children.
Right now what i am seeing is a chain...where the parent creates one child...and that child creates another ONE child..etc.
Here is what I have so far:
for (i=0; i<n;i++){
if (childpid = fork()) break;
}
if (childpid == -1){
perror ("
[Code]....
