Existing implementations vary on the result of a kill() with pid indicating an inactive process (a terminated process that has not been waited for by its parent). Some indicate success on such a call (subject to permission checking), while others give an error of [ESRCH]. Since the definition of process lifetime in this volume of POSIX.1-2008 covers inactive processes, the [ESRCH] error as described is inappropriate in this case. In particular, this means that an application cannot have a parent process check for termination of a particular child with kill(). (Usually this is done with the null signal; this can be done reliably with waitpid().
Regards,
Alister
Historic implementations in 1988 (when the first System Interfaces volume of the POSIX standards was approved) behaved both ways. (Notably UNIX System V succeeded, and 4.3BSD returned an ESRCH error.) The standard required the System V behavior, and that was further reinforced when the 2008 edition of the standard clarified that the lifetime of a process does not end until it is reaped.
But, of course, some implementations of UNIX-like systems do not conform to the standards.
Okay, I'm working within ansi C and Sun Solaris 7. I have a problem with zombies. I'm currently using the kill command to return the status of a process. How do I check for Zombie PIDs or the right function to return its PID from within a C program? (1 Reply)
Hi All
I need help, how can i kill zombies instead of rebooting the system.
Regards
System: sna Tue Apr 5 17:50:23 2005
Load averages: 0.05, 0.15, 0.22
168 processes: 157 sleeping, 5 running, 6 zombies
Cpu states:
CPU LOAD USER NICE... (5 Replies)
i'm writing small http proxy server (accept client -> connect to remote proxy server -> recv client's request -> send to remote proxy server -> get responce from remote proxy server -> send answer to client -> close connection to client and to remote proxy server) and having problems with fork().... (2 Replies)
I had a problem deleting a zombie process. It refused to be killed.
I even tried kill -9 process# but it refused.
Any other way of killing it? (7 Replies)
what are the precautions to be taken care for avoiding zombie process ? (8 Replies)
Discussion started by: Gopi Krishna P
8 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)