Strange SIGINT propagation between Parent/Child sh scripts
Good day,
I am trying to add signal handling capabilities to some of my scripts. Unfortunately, I am having some difficulty with the manner in which signals are propagated between parent/child processes. Consider the following example:
I have the following "parent" script:
which calls the following "child" script (as a background process):
When I execute the "parent" process with a ">./parent",
I observe that the expected behavior. I then send a
SIGINT to the "parent" via a ">kill -s SIGINT <ppid>" and
get the following screen output:
Quote:
SIGINT caught in Parent
Parent sending: kill -n 2 20944
Wait Status recorded when parent continues: 130
Parent Still Running after the child exits!
When I look at the processes that are still active, I see
that the child (and its sleep) has not been killed at all -
all that happened was that the sleep-process of the parent
was activated.
I would appreciate it if anybody has some idea what is happening
here.
I don't follow what these are...
this is what my text says...
"When a process is started, a duplicate of that process is created. This new process is called the child and the process that created it is called the parent. The child process then replaces the copy for the code the parent... (1 Reply)
:(
Since I'm fairly new to the scene and don't have much experience in shell programming, I decided to check out the net for a useful script or two.
What I'm looking for is a script that would let me enter a PID and then show the process tree associated with it.
So it would display the (grand-)... (2 Replies)
Hello all,
I have gone through the search and looked at posting about idle users and killing processes. Here is my question I would like to kill an idle user ( which I can do) but how can I asure that all of his process is also killed whit out tracing his inital start PID. I have tried this on a... (4 Replies)
Hello.
I have a global function name func1() that I am sourcing in from script A. I call the function from script B. Is there a way to find out which script called func1() dynamically so that the func1() can report it in the event there are errors?
Thanks (2 Replies)
Greets all. I'm using Slackware 12.0 with the bash shell. Calling my scripts with /bin/sh...
I'm building gnome-2.18.3 and I have all my build scripts ready and working but I'm calling them from a parent script which executes each child/build script in a certain order (for loop).
I have "set... (6 Replies)
Hi
I have a shell script A which calls another 10 shell scripts which run in background. How do i make the parent script wait for the child scripts complete, or in other words, i must be able to do a grep of parent script to find out if the child scripts are still running.
My Code:
... (5 Replies)
Hi all,
I am writing a script which calls other third party scripts that perform numerous actions. I have no control over these scripts.
My problem is, one of these scripts seems to execute and do what it is meant to do, but my calling / parent script always exits at that point. I need to... (4 Replies)
1. The problem statement, all variables and given/known data:
I need to make an program that in a loop creates one parent and five children with fork(). The problem i'm trying to solve is how to delete the parent and child of the childīs process.
2. Relevant commands, code, scripts,... (0 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)
does anyone know how to check in an 'if' statement if a particular directory is a child directory of a particular directory?
help ~ (2 Replies)
Discussion started by: ymc1g11
2 Replies
LEARN ABOUT ULTRIX
fork
fork(2) System Calls Manual fork(2)Name
fork - create a new process
Syntax
#include <sys/types.h>
#include <unistd.h>
pid = fork()
pid_t pid;
Description
The system call causes creation of a new process. The new process (child process) is an exact copy of the calling process except for the
following:
o The child process has a unique process ID.
o The child process has a different parent process ID (that is, the process ID of the parent process).
o The child process has its own copy of the parent's descriptors. These descriptors reference the same underlying objects, so that, for
instance, file pointers in file objects are shared between the child and the parent, so that a on a descriptor in the child process
can affect a subsequent read or write by the parent. This descriptor copying is also used by the shell to establish standard input
and output for newly created processes as well as to set up pipes.
o The child processes resource utilizations are set to 0. For further information, see
Return Values
Upon successful completion, returns a value of 0 to the child process and returns the process ID of the child process to the parent
process. Otherwise, a value of -1 is returned to the parent process, no child process is created, and the global variable errno is set to
indicate the error.
Diagnostics
The system call fails and no child process are created under the following conditions:
[EAGAIN] The system-imposed limit {PROC_MAX} on the total number of processes under execution would be exceeded.
[EAGAIN] The system-imposed limit {CHILD_MAX} on the total number of processes under execution by a single user would be exceeded.
[ENOMEM] There is insufficient swap space for the new process.
See Alsoexecve(2), wait(2)fork(2)