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
getpgid
getpid(2) System Calls getpid(2)
NAME
getpid, getpgrp, getppid, getpgid - get process, process group, and parent process IDs
SYNOPSIS
#include <unistd.h>
pid_t getpid(void);
pid_t getpgrp(void);
pid_t getppid(void);
pid_t getpgid(pid_t pid);
DESCRIPTION
The getpid() function returns the process ID of the calling process.
The getpgrp() function returns the process group ID of the calling process.
The getppid() function returns the parent process ID of the calling process.
The getpgid() function returns the process group ID of the process whose process ID is equal to pid, or the process group ID of the calling
process, if pid is equal to 0.
RETURN VALUES
The getpid(), getpgrp(), and getppid() functions are always successful and no return value is reserved to indicate an error.
Upon successful completion, getpgid() returns the process group ID. Otherwise, getpgid() returns (pid_t)-1 and sets errno to indicate the
error.
ERRORS
The getpgid() function will fail if:
EPERM The process whose process ID is equal to pid is not in the same session as the calling process, and the implementation does not
allow access to the process group ID of that process from the calling process.
ESRCH There is no process with a process ID equal to pid.
The getpgid() function may fail if:
EINVAL The value of the pid argument is invalid.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Committed |
+-----------------------------+-----------------------------+
|MT-Level |Async-Signal-Safe |
+-----------------------------+-----------------------------+
|Standard |See standards(5). |
+-----------------------------+-----------------------------+
SEE ALSO
Intro(2), exec(2), fork(2), getsid(2), setpgid(2), setpgrp(2), setsid(2), signal(3C), attributes(5), standards(5)
SunOS 5.11 27 Jan 2009 getpid(2)