netbsd man page for getsid

GETSID(2)						      BSD System Calls Manual							 GETSID(2)

NAME
     getsid -- get session ID

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     pid_t
     getsid(pid_t pid);

DESCRIPTION
     The getsid() function returns the session ID of the process specified by pid.  If pid is 0, the session ID of the calling process is
     returned.	The session ID is defined as the process group ID of the process that is the session leader.

ERRORS
     If an error occurs, getsid() returns -1 and the global variable errno is set to indicate the error, as follows:

     [ESRCH]		No process can be found corresponding to that specified by pid.

SEE ALSO
     getpgid(2), setsid(2), termios(4)

STANDARDS
     The getsid() function conforms to X/Open Portability Guide Issue 4, Version 2 (``XPG4.2'').

BSD
								   April 4, 2011							       BSD