getsid - get process group ID of session leader
pid_t getsid(pid_t pid);
The getsid() function obtains the process group ID of the
process that is the session leader of the process specified
If pid is (pid_t)0, it specifies the calling process.
Upon successful completion, getsid() returns the process
group ID of the session leader of the specified process.
Otherwise, it returns (pid_t)-1 and sets errno to indicate
The getsid() function will fail if:
EPERM The process specified by pid is not in the same ses-
sion as the calling process, and the implementation
does not allow access to the process group ID of the
session leader of that process from the calling pro-
ESRCH There is no process with a process ID equal to pid.
exec(2), fork(2), getpid(2), getpgid(2), setpgid(2), set-
Man(1) output converted with