$! captures the PID of the last process run in the background, that's correct. But that won't reset the value. Consider this: If you'd happen to start more than one background process, which one should reset $! ? What if you'd want to wait for the other process?
It's better to check the process list for the PID of the background job, and act based on that:
Hi,
I got a unix script which copies a file from my AIX machine to a file server using SCP command. I am calling this script 3 times in my process after a time interval say 5mins. My issue here is like most of the time its not sending the file at the first time run while other 2 will work fine.... (10 Replies)
Hi,
I have the following code which fails with return value 1.
sprintf(tmp, "rm -rf %s/* 2>/dev/null\n", dest);
rc = system( tmp );
rc is 1
The files exist and the paths are correct. I can do a manual copy but the application fails. All the calls to system() function fail with the same... (6 Replies)
I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends.
As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Hi Im running this script, which is supposed to find the max value build some tables and then stop running once all the tables are built. Thing is , it keeps assigning a null value to $h and then $g is null so it keep building tables i.e. testupdateNUL. How can I stop this? Here is what I have:
... (4 Replies)
Hi all
I'm trying to use someone else's software, which has a realloc that fails in it. This is probably due to memory limitations, as it only happens when I use this software on huge datasets.
First question : how to diagnose if it's a soft or hard limitation? I mean, if it's due to my... (10 Replies)
Not sure in which forum to post this. I'm trying here, in Programming.
I'm working on a PC with Intel Duo processor & 2GB of ram. OS is Ubuntu 10.04.
I'm having problems with a C++ program that makes extensive use of realloc(). It happens that as soon as the overall memory allocated(OS +... (14 Replies)
Hello All,
Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....?
I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping
through a string containing some of these "Illegal Characters". Now... (5 Replies)
The below while loop is in ksh on a SunOs server: SPARC-Enterprise 5.10
The ksh version is: Version M-11/16/88i
The intention of the below while loop is to read through a list of file names in files.txt and
delete each file from a server, one at a time. The delete works, the problem is that if... (6 Replies)
Hi,
I want to read file multiple times. Right now i am using while loop but that is not working.
ex.
While read line
do
while read line2
do
echo stmt1
#processing some data based on data.,
done < file2.txt
done < file1.txt # This will have 10... (4 Replies)
Here's my code:
awk -F '' 'NR==FNR {
if (/time/ && $5>10)
A=$2" "$3":"$4":"($5-01)
else if (/time/ && $5<01)
A=$2" "$3":"$4-01":"(59-$5)
else if (/time/ && $5<=10)
A=$2" "$3":"$4":0"($5-01)
else if (/close/) {
B=0
n1=n2;
... (2 Replies)
Discussion started by: klane
2 Replies
LEARN ABOUT CENTOS
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 terminal. 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 setsid(1), getsid(2), setpgid(2), setpgrp(2), tcgetsid(3), credentials(7)COLOPHON
This page is part of release 3.53 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 2013-02-11 SETSID(2)