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-rw-r--r--REORG.TODO/termios/tcgetsid.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/REORG.TODO/termios/tcgetsid.c b/REORG.TODO/termios/tcgetsid.c
new file mode 100644
index 0000000000..e49e6b12dd
--- /dev/null
+++ b/REORG.TODO/termios/tcgetsid.c
@@ -0,0 +1,62 @@
+/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <termios.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/* Return the session ID of FD.  */
+pid_t
+tcgetsid (int fd)
+{
+  pid_t pgrp;
+  pid_t sid;
+#ifdef TIOCGSID
+  static int tiocgsid_does_not_work;
+
+  if (! tiocgsid_does_not_work)
+    {
+      int serrno = errno;
+      int sid;
+
+      if (__ioctl (fd, TIOCGSID, &sid) < 0)
+	{
+	  if (errno == EINVAL)
+	    {
+	      tiocgsid_does_not_work = 1;
+	      __set_errno (serrno);
+	    }
+	  else
+	    return (pid_t) -1;
+	}
+      else
+	return (pid_t) sid;
+    }
+#endif
+
+  pgrp = tcgetpgrp (fd);
+  if (pgrp == -1)
+    return (pid_t) -1;
+
+  sid = getsid (pgrp);
+  if (sid == -1 && errno == ESRCH)
+    __set_errno (ENOTTY);
+
+  return sid;
+}