getpgid - Gets process group ID
Standard C Library (libc.a)
Specifies the process ID of the target process; zero implies the calling process.
The getpgid() function returns the process group ID of the process specified by the process ID pid. Specifying a pid of 0 (zero) returns the process group ID of the calling process.
The getpgid() function returns the process group ID of the process specified. If there was an error, a value of -1 is returned and errno is set to indicate the error.
If any of the following conditions occurs, the getpgid() function sets errno to the corresponding value: The specified process is not in the same session as the calling process, and the calling process lacks sufficient privilege to read the specified process. As released, Tru64 UNIX does not check the privilege. No process has been found that has a process ID identical to that specified by the pid parameter.
Functions: exec(2), fork(2), setpgid(2) delim off