Get a process group ID
Synopsis:
#include <unistd.h>
pid_t getpgid( pid_t pid );
Arguments:
- pid
- The ID of the process whose process group ID you want to get.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The getpgid() returns the group ID for the process
specified by pid. If pid is 0,
getpgid() returns the calling process's group ID.
Note:
In order to get the group ID of a process outside the calling process's
session, your process must have the
PROCMGR_AID_GETID ability enabled.
For more information, see
procmgr_ability().
The following definitions are worth mentioning:
- Process
- An executing instance of a program, identified by a nonnegative integer called a process ID.
- Process group
- A collection of one or more processes, with a unique process group ID.
A process group ID is a positive integer.
Returns:
A process group ID for success, or (pid_t)-1 if an error occurred
(errno
is set).
Errors:
- EPERM
- The calling process doesn't have the required permission; see
procmgr_ability().
- ESRCH
- The process specified by pid doesn't exist.
Classification:
POSIX 1003.1
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |