| SETSID(2) | System Calls Manual | SETSID(2) | 
setsid —
#include <unistd.h>
pid_t
  
  setsid(void);
setsid() function creates a new session. The calling
  process is the session leader of the new session, is the process group leader
  of a new process group and has no controlling terminal. The calling process is
  the only process in either the session or the process group.
Upon successful completion, the setsid()
    function returns the value of the process group ID of the new process group,
    which is the same as the process ID of the calling process.
setsid() returns -1 and the global
  variable errno is set to indicate the error, as follows:
EPERM]setsid() function conforms to IEEE
  Std 1003.1-1990 (“POSIX.1”).
| April 4, 2011 | NetBSD 10.0 |