signal in process communication:
I 'm a example in sun_unix that signal in process communication
It's here down but I only have freebsd in my machine.
how can i do the same in freebsd
eg:
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
int
main( void ){
void... (2 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)
Hello,
We are using AIX 5.2 ML 7.
One of the process in its log file said the following and stopped running.
Caught signal=5, exiting.
What would cause the signal 5 to be generated on an AIX box.
Please advise.
Thx
Jerardfjay (2 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)
Hi all,
Does a background process send a signal to its parent when completed? If so, how might i capture this signal?
I'm trying to write shell in c so that when a background process finishes, it prints a message to the console.
Thanks in advance for any advice. (1 Reply)
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)
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... (1 Reply)
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, I would like to ask, if is it possible to quit running loop in the script any other way than catching the trap signal. Ctrl-C ends only current running instance of process but not whole script. Any clues? (3 Replies)
Discussion started by: smoofy
3 Replies
LEARN ABOUT HPUX
sigrelse
sigset(3C)sigset(3C)NAME
sigset(), sighold(), sigrelse(), sigignore() - signal management
SYNOPSIS DESCRIPTION
The system defines a set of signals that can be delivered to a process. The set of signals is defined in signal(5), along with the meaning
and side effects of each signal. An alternate mechanism for handling these signals is defined here. The facilities described here should
not be used in conjunction with the other facilities described under signal(2) and sigspace(2).
allows the calling process to choose one of four ways to handle the receipt of a specific signal. sig specifies the signal and func speci-
fies the action handler.
sig can be any one of the signals described under signal(5) except or
func is assigned one of four values: or a function address. The actions prescribed by and are described under signal(5). The action pre-
scribed by and function address are described below:
Hold signal.
The signal sig is held upon receipt. Any pending signal of this signal type remains held. Only one signal of each type
is held.
Note: the signals and cannot be held.
function address Catch signal.
func must be a pointer to a function, the signal-catching handler, that is called when signal sig occurs. specifies that
the process calls this function upon receipt of signal sig. Any pending signal of this type is released. This handler
address is retained across calls to the other signal management functions listed here. Upon receipt of signal sig, the
receiving process executes the signal-catching function pointed to by func as described under signal(5) with the follow-
ing differences:
Before calling the signal-catching handler, the defined action of sig is set to During a normal return from the signal-
catching handler, the defined action is restored to func and any held signal of this type is released. If a non-local
goto (longjmp(3C)) is taken, must be called to restore the defined action to func and release any held signal of this
type.
holds the signal sig. restores the defined action of sig to that specified previously by and are used to establish critical regions of
code. is analogous to raising the priority level and deferring or holding a signal until the priority is lowered by
sets the action for signal sig to (see signal(5)).
RETURN VALUE
Upon successful completion, returns the previous value of the defined action for the specified signal sig. Otherwise, a value of is
returned and is set to indicate the error. is defined in
For the other functions, a 0 value indicates that the call succeeded. A -1 return value indicates an error occurred and is set to indicate
the reason.
ERRORS
fails and the defined action for sig is not changed if any of the following occur:
The func argument points to memory that is not a valid part of the process address space. Reliable detection of this
error is implementation dependent.
and and fail and the defined action for sig is not changed if any of the following occur:
sig is not a valid signal number.
An attempt is made to ignore, hold, or supply a handler
for a signal that cannot be ignored, held, or caught; see signal(5).
WARNINGS
These signal facilities should not be used in conjunction with signal(2) and sigspace(2).
SEE ALSO kill(1), kill(2), pause(2), signal(2), sigspace(2), wait(2), abort(3C), setjmp(3C), sigpause(3C), signal(5).
STANDARDS CONFORMANCE sigset(3C)