1.\" Copyright (c) 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.roff% 5.\" 6.\" @(#)setsid.2 8.1 (Berkeley) 06/04/93 7.\" 8.Dd "" 9.Dt SETSID 2 10.Os 11.Sh NAME 12.Nm setsid 13.Nd create session and set process group ID 14.Sh SYNOPSIS 15.Fd #include <sys/types.h> 16.Ft pid_t 17.Fn setsid "void" 18.Sh DESCRIPTION 19The 20.Nm setsid 21function creates a new session. 22The calling process is the session leader of the new session, is the 23process group leader of a new process group and has no controlling 24terminal. 25The calling process is the only process in either the session or the 26process group. 27.Pp 28Upon successful completion, the 29.Nm setsid 30function returns the value of the process group ID of the new process 31group, which is the same as the process ID of the calling process. 32.Sh ERRORS 33If an error occurs, 34.Nm setsid 35returns -1 and the global variable 36.Va errno 37is set to indicate the error, as follows: 38.Bl -tag -width Er 39.It Bq Er EPERM 40The calling process is already a process group leader, or the process 41group ID of a process other than the calling process matches the process 42ID of the calling process. 43.El 44.Sh SEE ALSO 45.Xr setpgid 3 , 46.Xr tcgetpgrp 3 , 47.Xr tcsetpgrp 3 48.Sh STANDARDS 49The 50.Nm setsid 51function is expected to be compliant with the 52.St -p1003.1-88 53specification. 54