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. 

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:

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)