NAME

getsid − get session ID

SYNOPSIS

#include <sys/types.h> pid_t getsid(pid_t pid);

DESCRIPTION

The function getsid returns the session ID of the process whose process ID is equal to pid.  If pid is equal to (pid_t)0, getsid returns the session ID of the calling process. 

The call TIOCGSID is used to get the session ID of the controlling terminal. 

RETURN VALUE

Upon successful completion, the function getsid returns the session ID of the specified process; otherwise, it returns a value of (pid_t)−1 and sets errno to indicate an error. 

ERRORS

Under the following conditions, the function getsid fails and sets errno to:

EINVAL if pid is not legal. 

EPERM if 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 session ID of that process from the calling process. 

ESRCH if there is no process with a process ID equal to pid. 

SEE ALSO

exec(2), fork(2), getpid(2), setpgid(2), setsid(2), tcgetsid(3C), sgtty(7), termios(7). 

CX/UX Programmer’s Reference Manual