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-rw-r--r--login/getutid_r.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/login/getutid_r.c b/login/getutid_r.c
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+++ b/login/getutid_r.c
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+/* Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <unistd.h>
+#include <utmp.h>
+
+
+/* For implementing this function we don't use the getutent_r function
+   because we can avoid the reposition on every new entry this way.  */
+int
+getutid_r (const struct utmp *id, struct utmp **utmp,
+	   struct utmp_data *utmp_data)
+{
+  /* Open utmp file if not already done.  */
+  if (utmp_data->ut_fd == -1)
+    {
+      setutent_r (utmp_data);
+      if (utmp_data->ut_fd == -1)
+	return -1;
+    }
+
+  /* Position file correctly.  */
+  if (lseek (utmp_data->ut_fd, utmp_data->loc_utmp, SEEK_SET) == -1)
+    return -1;
+
+  do
+    {
+      /* Read the next entry.  */
+      if (read (utmp_data->ut_fd, &utmp_data->ubuf, sizeof (struct utmp))
+	  != sizeof (struct utmp))
+	{
+	  errno = ESRCH;
+	  return -1;
+	}
+
+      /* Update position pointer.  */
+      utmp_data->loc_utmp += sizeof (struct utmp);
+    }
+  while (id->ut_type != utmp_data->ubuf.ut_type);
+
+  *utmp = &utmp_data->ubuf;
+
+  return 0;
+}