SETSID(2) System Calls Manual SETSID(2)
setsid -- create session and set process group ID
Standard C Library (libc, -lc)
The 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.
If an error occurs, setsid() returns -1 and the global variable errno is
set to indicate the error, as follows:
[EPERM] The calling process is already a process group leader,
or the process group ID of a process other than the
calling process matches the process ID of the calling
getsid(2), setpgid(2), tcgetpgrp(3), tcsetpgrp(3)
The setsid() function conforms to IEEE Std 1003.1-1990 (``POSIX.1'').
NetBSD 6.1.5 April 4, 2011 NetBSD 6.1.5