65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
/* Copyright (C) 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <errno.h>
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#include <termios.h>
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#include <sys/ioctl.h>
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#include <sys/types.h>
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#include <unistd.h>
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/* Return the session ID of FD. */
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pid_t
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tcgetsid (fd)
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int fd;
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{
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pid_t pgrp;
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pid_t sid;
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#ifdef TIOCGSID
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static int tiocgsid_works = 1;
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if (tiocgsid_works)
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{
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int serrno = errno;
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int sid;
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if (__ioctl (fd, TIOCGSID, &sid) < 0)
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{
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if (errno == EINVAL)
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{
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tiocgsid_works = 0;
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__set_errno (serrno);
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}
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else
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return (pid_t) -1;
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}
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else
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return (pid_t) sid;
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}
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#endif
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pgrp = tcgetpgrp (fd);
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if (pgrp == -1)
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return (pid_t) -1;
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sid = getsid (pgrp);
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if (sid == -1 && errno == ESRCH)
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__set_errno (ENOTTY);
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return sid;
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}
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