03-08-2005
Kill Signal
Hello,
I'm doing a project of OS simulation (Process Scheduling, to be very specific). Can anyone, please, explain what exactly happens in the background when we see "Sending all processes the KILL signal...........". How is it sent to each process? Is it that something like a boolean is stored somewhere and each process checks that before its normal execution?? Is it stored somewhere with the process image?? Does every process get a chance to execute something after this signal is passed?? Does PCB come into the picture?? I'm totally lost from all the fragmented info i found thru google (teoma, askjeeves, etc).
Please, if anybody can help me out with this quickly, it would be highly appreciated!!
Ameya
=====
There are 10 kinds of programmers.
Those who know Operating Systems, and,
those who don't!!!!!!!!
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hello e'bdy,
We have WebSphere MQ running on AIX 5.1
Every weekend MQ receives a kill -30 signal from some process or user and offloads a big error file. There is no way in MQ through which that process can be tracked.
Is there something which i can do on UNIX level to trap the process?
Best... (3 Replies)
Discussion started by: jhaavinash
3 Replies
2. UNIX for Advanced & Expert Users
Hi All,
I am unable to kill a process using kill command. I am using HP-UX system. I have tried with kill -9 and i have root privilages.
How can i terminate this daemon ? ? ?
Regards,
Vijay Hegde (3 Replies)
Discussion started by: VijayHegde
3 Replies
3. Programming
Hi all
i have simple c program , when i wish to kill the app
im using kill(0,-9) , but it seams this command don't do any thing and the program.
just ignore it .
what im doing wrong here ?
im using HP-UX ia64
Thanks (9 Replies)
Discussion started by: umen
9 Replies
4. UNIX for Advanced & Expert Users
Hi,
I have a process with say pid x. What is the difference b/n
kill x and kill -9 x in unix
Thanks
Ammu (2 Replies)
Discussion started by: ammu
2 Replies
5. Shell Programming and Scripting
Sorry, posted the question in other forum. (0 Replies)
Discussion started by: sudhamacs
0 Replies
6. Linux
I want to Kill a process without using kill command as i don't have privileges to kill the process. I know the pid and i am using Linux 2.6.9 OS. (6 Replies)
Discussion started by: sudhamacs
6 Replies
7. Shell Programming and Scripting
I just want to trap kill -9 signal issued by any of user from any terminal and just capture that user terminal who had raised this kill -9 command (1 Reply)
Discussion started by: puneet.goel
1 Replies
8. UNIX for Dummies Questions & Answers
Hi,
What is the use of the signal -3 in kill command in unix?
I read the meaning and typical use of this signal in one of the Oreilly books as below.
Quit -- stop running (and dump core). Sent when you type CTRL-\.
what does the CTRL-\ command do? Is it the combination of CTRL and... (6 Replies)
Discussion started by: venkatesht
6 Replies
9. Solaris
Hello everyone,
I have a process that I want to kill. I have tried kill-9 PID but it doesn't work. I have tried preap PID but it doesn't work too.
The parent of my process is the process whose PID is 1, so I can't kill it.
My OS is a Solaris 9.
Can anyone help me understand what's going... (3 Replies)
Discussion started by: adilyos
3 Replies
10. Shell Programming and Scripting
Good afternoon
I need to KILL a process in a single command sentence, for example:
kill -9 `ps -aef | grep 'CAL255.4ge' | grep -v grep | awk '{print $2}'`
That sentence Kills the process ID corresponding to the program CAL255.4ge.
However it is possible that the same program... (6 Replies)
Discussion started by: enriquegm82
6 Replies
KILL(2) BSD System Calls Manual KILL(2)
NAME
kill -- send signal to a process
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <signal.h>
int
kill(pid_t pid, int sig);
DESCRIPTION
The kill() function sends the signal given by sig to pid, a process or a group of processes. sig may be one of the signals specified in
sigaction(2) or it may be 0, in which case error checking is performed but no signal is actually sent. This can be used to check the valid-
ity of pid.
For a process to have permission to send a signal to a process designated by pid, the real or effective user ID of the receiving process must
match that of the sending process or the user must have appropriate privileges (such as given by a set-user-ID program or the user is the
super-user). A single exception is the signal SIGCONT, which may always be sent to any descendant of the current process.
If pid is greater than zero:
sig is sent to the process whose ID is equal to pid.
If pid is zero:
sig is sent to all processes whose process group ID is equal to the process group ID of the sender, and for which the process has
permission; this is a variant of killpg(3).
If pid is -1:
If the user has super-user privileges, the signal is sent to all processes excluding system processes and the process sending the
signal. If the user is not the super user, the signal is sent to all processes with the same uid as the user excluding the process
sending the signal. No error is returned if any process could be signaled.
For compatibility with System V, 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. This is a variant of killpg(3).
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
kill() will fail and no signal will be sent if:
[EINVAL] sig is not a valid signal number.
[ESRCH] No process can be found corresponding to that specified by pid.
[ESRCH] The process id was given as 0 but the sending process does not have a process group.
[EPERM] The sending process is not the super-user and its effective user id does not match the effective user-id of the receiving
process. When signaling a process group, this error is returned if any members of the group could not be signaled.
SEE ALSO
getpgrp(2), getpid(2), sigaction(2), killpg(3), signal(7)
STANDARDS
The kill() function is expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1'').
BSD
April 19, 1994 BSD