NAME

     getsid — get process session

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     pid_t
     getsid(pid_t pid);

DESCRIPTION

     The session ID of the process identified by pid is returned by getsid().  If pid is zero,
     getsid() returns the session ID of the current process.

RETURN VALUES

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

ERRORS

     The getsid() system call will succeed unless:

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

     Note that an implementation may restrict this system call to processes within the same
     session ID as the calling process.

SEE ALSO

     getpgid(2), getpgrp(2), setpgid(2), setsid(2), termios(4)

HISTORY

     The getsid() system call appeared in FreeBSD 3.0.  The getsid() system call is derived from
     its usage in AT&T System V UNIX.