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glibc  2.9
login_tty.c
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00001 /*-
00002  * Copyright (c) 1990, 1993
00003  *     The Regents of the University of California.  All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 4. Neither the name of the University nor the names of its contributors
00014  *    may be used to endorse or promote products derived from this software
00015  *    without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00027  * SUCH DAMAGE.
00028  */
00029 
00030 #if defined(LIBC_SCCS) && !defined(lint)
00031 static char sccsid[] = "@(#)login_tty.c   8.1 (Berkeley) 6/4/93";
00032 #endif /* LIBC_SCCS and not lint */
00033 
00034 #include <errno.h>
00035 #include <sys/param.h>
00036 #include <sys/ioctl.h>
00037 #include <unistd.h>
00038 #include <fcntl.h>
00039 #include <utmp.h>
00040 
00041 int
00042 login_tty(fd)
00043        int fd;
00044 {
00045        (void) setsid();
00046 #ifdef TIOCSCTTY
00047        if (ioctl(fd, TIOCSCTTY, (char *)NULL) == -1)
00048               return (-1);
00049 #else
00050        {
00051          /* This might work.  */
00052          char *fdname = ttyname (fd);
00053          int newfd;
00054          if (fdname)
00055            {
00056              if (fd != 0)
00057               (void) close (0);
00058              if (fd != 1)
00059               (void) close (1);
00060              if (fd != 2)
00061               (void) close (2);
00062              newfd = open (fdname, O_RDWR);
00063              (void) close (newfd);
00064            }
00065        }
00066 #endif
00067        while (dup2(fd, 0) == -1 && errno == EBUSY)
00068          ;
00069        while (dup2(fd, 1) == -1 && errno == EBUSY)
00070          ;
00071        while (dup2(fd, 2) == -1 && errno == EBUSY)
00072          ;
00073        if (fd > 2)
00074               (void) close(fd);
00075        return (0);
00076 }
00077 libutil_hidden_def (login_tty)