Parent process starts before the child using signal, in C
Hi, i want that the parent process start before the child, this code doesn't work,
if the child start before the parent it wait for signal, then the father send the signal SIGALRM and the child catch it and call printf;
else the father call printf and send the signal to the child that call its printf;
in any case nothing happens:
Hi everybody,
I'm trying to understand how a parent and child processes interact.
This function( below) basically measures the fork time from the perspective of the parent only.
what i would like to know is how to measure the time from the perspective of parent and child (ie: inserting... (0 Replies)
I want to catch SIGCHLD signal in parent process. I can't use wait() system call to catch SIGCHLD according to project requirment.
Operating system linux 3.1
can any one have a solution for this.
Thanking you,
ranjan (2 Replies)
i am creating children processes using fork system call
every child i create goes to sleep for random time.
when child stops running how can i catch his signal and turminate the child (2 Replies)
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)
Hi All,
I facing a problem in handling signals between parent process communication. I am trying to send a signal(SIGINT) from child to parent. I am using kill function to do so and I am trying to read the signal using sigaction(). But the program is ending abruptly and I am not able to figure out... (4 Replies)
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)
I'm trying to do a program that makes activate an signal (SINGALARM) when the next child of a son appears but this not works.
I have to caught the next child o the other (pid), to send a singnal which inform a menssage.
It's anything worng in the code?
thanks.
the code:
#include... (2 Replies)
Hello. I want to make a child do some stuff,wait,then the parent does some stuff and then child does some stuff and waits again.I have made the following but it does not work.Can anybody help me?
pid1 = fork();
if (pid1 == -1)
{
perror("Can't create child\n");
... (18 Replies)
Hello, everyone.
Here's a program:
pid_t pid = fork();
if (0 == pid) // child process
{
execvp ...;
}
I send a signal (such as SIGINT) to the parent process, the child process receive the signal as well as the parent process.
However I don't want to child process to receive the... (7 Replies)
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 ULTRIX
kill
kill(2) System Calls Manual kill(2)Name
kill - send signal to a process
Syntax
#include <sys/types.h>
#include <signal.h>
kill(pid, sig)
pid_t pid;
int sig;
Description
The system call sends the signal sig to a process specified by the process number pid. The sig can be a signal specified in a call or it
can be 0. If the sig is 0, error checking is performed, but a signal is not sent. This call can be used to check the validity of pid.
The sending and receiving processes must have the same effective user ID, otherwise this call is restricted to the superuser with the
exception of the signal SIGCONT. The signal SIGCONT can always be sent to a child or grandchild of the current process.
If the process number is 0, the signal is sent to all other processes in the sender's process group.
If the process number is negative but not -1, the signal is sent to all processes whose process-group-id is equal to the absolute value of
the process number.
The above two options are variants of
If the process number is -1, and the user is the superuser, the signal is broadcast for all processes except to system processes and the
process sending the signal.
Processes may send signals to themselves.
Environment
System Five
POSIX
When your program is compiled in the System V or POSIX environment, a signal is sent if either the real or effective uid of the sending
process matches the real or saved-set-uid (as described in ) of the receiving process. In addition, any process can use a pid of -1, and
the signal is sent to all processes subject to these permission checks.
In POSIX mode, the pid argument is of type pid_t.
Return Values
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned, and is set to indicate the error.
Diagnostics
The system call fails under the following conditions:
[EINVAL] The sig is not a valid signal number.
[EPERM] The sending process is not the superuser, and its effective user ID does not match the effective user ID of the receiving
process.
[ESRCH] No process can be found corresponding to that specified by pid.
See Alsoexecve(2), getpgrp(2), getpid(2), killpg(2), sigvec(2), pause(3)kill(2)