I have solved it with wait(NULL). But now I have no idea how to put pipes into it. I mean the first child generate for example random number and send it via pipe to another children and to the last child. I was thinking about to use 2d array pipe (int pipe[Number_of_children][2]), but I don't know how to put it into the for loop..
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,
I have developed a datastage job...which has many process running in parallel..but because of Fork Error my job is not working:(
Can any body help me out to solve this Fork error problem.:rolleyes:
My Os is SUNOS.
IS there any setting in Unix through admin where in if i set some paramter... (8 Replies)
Hi,
I was honing my linux programming skill when this nuisance started bugging me. I wanted to create an empty file creator program. While creating a large file it must print # for progress bar. But the output shows it happening reverse way. ie. first it copies file and shows the progress... (7 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)
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 CENTOS
tcl_reapdetachedprocs
Tcl_DetachPids(3) Tcl Library Procedures Tcl_DetachPids(3)__________________________________________________________________________________________________________________________________________________NAME
Tcl_DetachPids, Tcl_ReapDetachedProcs, Tcl_WaitPid - manage child processes in background
SYNOPSIS
#include <tcl.h>
Tcl_DetachPids(numPids, pidPtr)
Tcl_ReapDetachedProcs()
Tcl_Pid
Tcl_WaitPid(pid, statusPtr, options)
ARGUMENTS
int numPids (in) Number of process ids contained in the array pointed to by pidPtr.
int *pidPtr (in) Address of array containing numPids process ids.
Tcl_Pid pid (in) The id of the process (pipe) to wait for.
int *statusPtr (out) The result of waiting on a process (pipe). Either 0 or ECHILD.
int options (in) The options controlling the wait. WNOHANG specifies not to wait when checking the process.
_________________________________________________________________DESCRIPTION
Tcl_DetachPids and Tcl_ReapDetachedProcs provide a mechanism for managing subprocesses that are running in background. These procedures
are needed because the parent of a process must eventually invoke the waitpid kernel call (or one of a few other similar kernel calls) to
wait for the child to exit. Until the parent waits for the child, the child's state cannot be completely reclaimed by the system. If a
parent continually creates children and doesn't wait on them, the system's process table will eventually overflow, even if all the children
have exited.
Tcl_DetachPids may be called to ask Tcl to take responsibility for one or more processes whose process ids are contained in the pidPtr
array passed as argument. The caller presumably has started these processes running in background and does not want to have to deal with
them again.
Tcl_ReapDetachedProcs invokes the waitpid kernel call on each of the background processes so that its state can be cleaned up if it has
exited. If the process has not exited yet, Tcl_ReapDetachedProcs does not wait for it to exit; it will check again the next time it is
invoked. Tcl automatically calls Tcl_ReapDetachedProcs each time the exec command is executed, so in most cases it is not necessary for
any code outside of Tcl to invoke Tcl_ReapDetachedProcs. However, if you call Tcl_DetachPids in situations where the exec command may
never get executed, you may wish to call Tcl_ReapDetachedProcs from time to time so that background processes can be cleaned up.
Tcl_WaitPid is a thin wrapper around the facilities provided by the operating system to wait on the end of a spawned process and to check a
whether spawned process is still running. It is used by Tcl_ReapDetachedProcs and the channel system to portably access the operating sys-
tem.
KEYWORDS
background, child, detach, process, wait
TclTcl_DetachPids(3)