1/*********************************************************************** 2* * 3* This software is part of the ast package * 4* Copyright (c) 1985-2012 AT&T Intellectual Property * 5* and is licensed under the * 6* Eclipse Public License, Version 1.0 * 7* by AT&T Intellectual Property * 8* * 9* A copy of the License is available at * 10* http://www.eclipse.org/org/documents/epl-v10.html * 11* (with md5 checksum b35adb5213ca9657e911e9befb180842) * 12* * 13* Information and Software Systems Research * 14* AT&T Research * 15* Florham Park NJ * 16* * 17* Glenn Fowler <gsf@research.att.com> * 18* David Korn <dgk@research.att.com> * 19* Phong Vo <kpv@research.att.com> * 20* * 21***********************************************************************/ 22#pragma prototyped 23 24#include <ast.h> 25 26#if _lib_setsid 27 28NoN(setsid) 29 30#else 31 32#include <ast_tty.h> 33#include <error.h> 34 35/* 36 * become new process group leader and drop control tty 37 */ 38 39pid_t 40setsid(void) 41{ 42 int pg; 43#ifdef TIOCNOTTY 44 int fd; 45#endif 46 47 /* 48 * become a new process group leader 49 */ 50 51 if ((pg = getpid()) == getpgrp()) 52 { 53 errno = EPERM; 54 return(-1); 55 } 56 setpgid(pg, pg); 57#ifdef TIOCNOTTY 58 59 /* 60 * drop the control tty 61 */ 62 63 if ((fd = open("/dev/tty", O_RDONLY|O_cloexec)) >= 0) 64 { 65 ioctl(fd, TIOCNOTTY, 0); 66 close(fd); 67 } 68#else 69 70 /* 71 * second child in s5 to avoid reacquiring the control tty 72 */ 73 74#if _lib_fork && HUH920711 /* some s5's botch this */ 75 switch (fork()) 76 { 77 case -1: 78 exit(1); 79 case 0: 80 break; 81 default: 82 exit(0); 83 } 84#endif 85 86#endif 87 return(pg); 88} 89 90#endif 91