02-01-2004
printing ppid,child pid,pid
question: for the below program
i just printed the value for pid, child pid and parent pid
why does it give me 6 values? i assume ppid is 28086
but can't figure out why there are 5 values printed instead of just two!
can someone comment on that!
#include<stdio.h>
#define DIM 8
int main()
{
int pid, i, ans;
int arr[DIM] = {1,2,3,4,5,6,7,8};
pid = fork();
printf("%d\n",pid);
printf("%d\n",getpid());
printf("%d\n",getppid());
}
======
the output is
$./a.out
0
28873
28872
28873
28872
28086
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LEARN ABOUT OPENSOLARIS
setpgid
setpgid(2) System Calls setpgid(2)
NAME
setpgid - set process group ID
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
int setpgid(pid_t pid, pid_t pgid);
DESCRIPTION
The setpgid() function sets the process group ID of the process with ID pid to pgid.
If pgid is equal to pid, the process becomes a process group leader. See Intro(2) for more information on session leaders and process group
leaders.
If pgid is not equal to pid, the process becomes a member of an existing process group.
If pid is equal to 0, the process ID of the calling process is used. If pgid is equal to 0, the process specified by pid becomes a process
group leader.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.
ERRORS
The setpgid() function will fail if:
EACCES The pid argument matches the process ID of a child process of the calling process and the child process has successfully executed
one of the exec family of functions (see exec(2)).
EINVAL The pgid argument is less than (pid_t) 0 or greater than or equal to PID_MAX, or the calling process has a controlling terminal
that does not support job control.
EPERM The process indicated by the pid argument is a session leader.
EPERM The pid argument matches the process ID of a child process of the calling process and the child process is not in the same ses-
sion as the calling process.
EPERM The pgid argument does not match the process ID of the process indicated by the pid argument, and there is no process with a
process group ID that matches pgid in the same session as the calling process.
ESRCH The pid argument does not match the process ID of the calling process or of a child process of the calling process.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |Async-Signal-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
Intro(2), exec(2), exit(2), fork(2), getpid(2), getsid(2), attributes(5), standards(5)
SunOS 5.11 28 Dec 1996 setpgid(2)