Here we are trying to get PID of a child process in parent process. So I believe, it can be done only if child process runs in background. If process runs in foreground, ps command will execute only after child process is completed and then PID can't be obtained.
sleep is used to avoid cases when child process make take a while to get started.
~Others, Please correct if anything wrong here.
Last edited by anurag.singh; 12-21-2010 at 12:47 PM..
hi,
I am new ot unix. So, can i write a shell(c shell or korn shell) program to access internet? I mean if I run the program, it can access specified url and then copy the html to a file? Can anyone help me? And how can make the program runs every 1 hr?
new comer (2 Replies)
Hi,
i want to write a script that executes a program (exec?) .
this program then requires a filename as input.
how do i give it this input in the script so the program will be complete run and close by the script.
e.g.
exec prog.exe
program then asks for filename
"enter filename:"... (1 Reply)
Hi,
I am a complete newbie for unix. I have just installed mysql on my MAC. I was wondering every time I wanted to use mysql I had to ./mysql or sh mysql everytime on /usr/local/bin/mysql/bin. How can I execute the mysql program without using ./ or sh. I chmod +x already. And what do I have to... (3 Replies)
Hi All,
well , i am facing this problem.. i have tried a few sample codes but there isn't any solution . could anyone please give a sample code as of how to do this...
Please see the below details...and read the details carefully.
I have written some code, logic is
1)from... (4 Replies)
Hello,
I have a c program executable which I need to run inside a shell script.
But the c program runs in a subshell because of which all the actions done by the c program is not available to the current shell.
Is there any way to execute a C program binary executable in the current shell? (4 Replies)
My professor gave me a code with no errors.
When I compile it's fine, it doesn't show any errors, but when I try to execute it shows this:
line 3: syntax error near unexpected token '('
line 3: 'int main()'
I searched through the Internet but I couldn't find any solution. Please!!!... (1 Reply)
Hi there,
When I am trying to execute any shell script.
The shell script only execute line 1 and I notice that the rest o the program was not executed. Please advise.
# bash +x vmscript-4.sh
Even when I enter this command there is not output.
sudo su
cd /tmp
cp... (2 Replies)
Discussion started by: alvinoo
2 Replies
LEARN ABOUT DEBIAN
setsid
SETSID(2) Linux Programmer's Manual SETSID(2)NAME
setsid - creates a session and sets the process group ID
SYNOPSIS
#include <unistd.h>
pid_t setsid(void);
DESCRIPTION
setsid() creates a new session if the calling process is not a process group leader. The calling process is the leader of the new session,
the process group leader of the new process group, and has no controlling tty. The process group ID and session ID of the calling process
are set to the PID of the calling process. The calling process will be the only process in this new process group and in this new session.
RETURN VALUE
On success, the (new) session ID of the calling process is returned. On error, (pid_t) -1 is returned, and errno is set to indicate the
error.
ERRORS
EPERM The process group ID of any process equals the PID of the calling process. Thus, in particular, setsid() fails if the calling
process is already a process group leader.
CONFORMING TO
SVr4, POSIX.1-2001.
NOTES
A child created via fork(2) inherits its parent's session ID. The session ID is preserved across an execve(2).
A process group leader is a process with process group ID equal to its PID. In order to be sure that setsid() will succeed, fork(2) and
_exit(2), and have the child do setsid().
SEE ALSO getsid(2), setpgid(2), setpgrp(2), tcgetsid(3), credentials(7)COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2008-12-03 SETSID(2)