* In case the child process his a error, this will exiting without sending SIGALRM to parent, which will make parent to keep on printing the "#", even if child has died, so parent will keep on printing the #.
* #'s are relative to the size of the file you are creating. (they should).not to the time. For a small sized file, their will be 1-2 hashes. but for big, their can be 20-30 hashes. This doesn't tells the user real progress.
May be you can try without using fork.
-Dheeraj
Thanks for your kind reply.
I really missed the time factor . Can you give some code to implement the same. A brief pseudo code will suffice. Also why many are telling me not to use fork(in other forums too.) whereas its the default multitasking facility in *nix system.
Quote:
Originally Posted by Corona688
Since the #'s are probably( ) intended for human reading and not as output for another process, you should print them to standard error instead of standard output to kill two birds with one stone. stderr is unbuffered by convention.
Code:
// always unbuffered, fflush not needed
fputc('#', stderr);
Thanks to you also ! Never knew that fact about stderr
Hi,
Consider the following piece of code:
int main(void) {
int i;
pid_t pidp;
for (i=0;i<4;i++) {
switch (pidp=fork()) {
case -1:
fprintf(stdout, "Error during fork.\n");
exit (1);
case 0:
fprintf(stdout, "From child: I am... (4 Replies)
i'm just trying to make 2 process read from the same 1 line a time. For some reason only the child reads.
#include<stdio.h>
#include <sys/types.h>
void getlinefromfilep(void);
void getlinefromfilec(void);
int see=0;
FILE * fileptr1;
//need globe variable to tell pro3 to stop
main()... (3 Replies)
Hi. One of my company's customers requires mails to be sent to them to use TLS. Thanks to some good documentation on the web, I've got this mostly figured out, but now I'm stuck at generating the CSR.
My company's mail domain is sg.bunny.com (not real address, obviously), but the email gateway... (0 Replies)
I have this little program ...
int main(void){
printf("Before");
fork();
printf("After");
}
output is this.....
BeforeAfterBeforeAfter
Shouldnt it be.....BeforeAfterAfter
After parent is forked child receives the copy of program and continues from next statement... (3 Replies)
Hi All,
In my program i am handling SIGHUP signal. In the handler i fork and then exec on child process same binary file which is running. Parent process will die after 10 mins.
Now my child process which was exec with same binary file is not receiving SIGHUP signal. Below is the progran code:... (6 Replies)
i am a beginner of C, and i tired to fork multiple child and all of them belongs to same parents and each of child responsible for printing individual data.
but i don't have any idea how to do......
Can any body help? thanks a lot really. (7 Replies)
Hi, can someone please help me with creating mutltiple fork.. I was expecting something like this:
I am a child: 1 PID: 1215
I am a child: 2 PID: 1216
I am a child: 3 PID: 1217
I am a child: 4 PID: 1218
I am a child: 5 PID: 1219
I am a child: 6 PID: 1215
I am a child: 7 PID: 1216
I am a... (4 Replies)
Hello everyone, this is my first post.
I have a task to use a fork to create multiple processes and then use execlp to run another program to add 2 numbers.
The problem I am having is we are supposed to use the exit() call in the execlp to return the small integer. This is a bad way to... (3 Replies)
Good evening everyone. I have my finals and I'm facing a problem:
I have a for cycle that is supposed to fork 2 children but somehow it forks only the first one.
What am I doing wrong ?
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>... (1 Reply)
Hi guys,
I have the following code:
int main(int argc, char *argv)
{
int pid1,pid2,i=0;
pid1=fork();
i+=2;
if(!pid1) i++;
if(i%3) pid2=fork();
if (pid2==0)
{
printf("sea \n ");
i-=1;
}
if(i>=2)... (4 Replies)
Discussion started by: pfpietro
4 Replies
LEARN ABOUT X11R4
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)
09-25-2009
) whereas its the default multitasking facility in *nix system. 
) intended for human reading and not as output for another process, you should print them to standard error instead of standard output to kill two birds with one stone. stderr is unbuffered by convention.