1 files changed, 50 insertions, 0 deletions
diff --git a/sysdeps/generic/group_member.c b/sysdeps/generic/group_member.c
new file mode 100644
index 0000000000..31d2e87f53
--- /dev/null
+++ b/sysdeps/generic/group_member.c
@@ -0,0 +1,50 @@
+/* `group_member' -- test if process is in a given group.
+Copyright (C) 1995 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 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., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <limits.h>
+
+#ifndef NGROUPS_MAX
+#define NGROUPS_MAX	16	/* First guess.  */
+#endif
+
+int
+__group_member (gid)
+     gid_t gid;
+{
+  int n, size;
+  gid_t *groups;
+
+  size = NGROUPS_MAX;
+  do
+    {
+      groups = __alloca (size * sizeof *groups);
+      n = __getgroups (size, groups);
+      size *= 2;
+    } while (n == size / 2);
+
+  while (n > 0)
+    if (groups[n--] == gid)
+      return 1;
+
+  return 0;
+}
+weak_alias (__group_member, group_member)