1 files changed, 104 insertions, 0 deletions
diff --git a/lib/getugroups.c b/lib/getugroups.c
new file mode 100644
index 0000000..970192e
--- /dev/null
+++ b/lib/getugroups.c
@@ -0,0 +1,104 @@
+/* getugroups.c -- return a list of the groups a user is in
+
+   Copyright (C) 1990, 1991, 1998, 1999, 2000, 2003, 2004, 2005, 2006
+   Free Software Foundation.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by David MacKenzie. */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <stdio.h> /* grp.h on alpha OSF1 V2.0 uses "FILE *". */
+#include <grp.h>
+
+#include <unistd.h>
+
+#include <errno.h>
+#ifndef EOVERFLOW
+# define EOVERFLOW EINVAL
+#endif
+
+/* Some old header files might not declare setgrent, getgrent, and endgrent.
+   If you don't have them at all, we can't implement this function.
+   You lose!  */
+struct group *getgrent ();
+
+#include <string.h>
+
+#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))
+
+/* Like `getgroups', but for user USERNAME instead of for the current
+   process.  Store at most MAXCOUNT group IDs in the GROUPLIST array.
+   If GID is not -1, store it first (if possible).  GID should be the
+   group ID (pw_gid) obtained from getpwuid, in case USERNAME is not
+   listed in /etc/groups.
+   Always return the number of groups of which USERNAME is a member.  */
+
+int
+getugroups (int maxcount, GETGROUPS_T *grouplist, char *username, gid_t gid)
+{
+  struct group *grp;
+  register char **cp;
+  register int count = 0;
+
+  if (gid != (gid_t) -1)
+    {
+      if (maxcount != 0)
+	grouplist[count] = gid;
+      ++count;
+    }
+
+  setgrent ();
+  while ((grp = getgrent ()) != 0)
+    {
+      for (cp = grp->gr_mem; *cp; ++cp)
+	{
+	  int n;
+
+	  if ( ! STREQ (username, *cp))
+	    continue;
+
+	  /* See if this group number is already on the list.  */
+	  for (n = 0; n < count; ++n)
+	    if (grouplist && grouplist[n] == grp->gr_gid)
+	      break;
+
+	  /* If it's a new group number, then try to add it to the list.  */
+	  if (n == count)
+	    {
+	      if (maxcount != 0)
+		{
+		  if (count >= maxcount)
+		    {
+		      endgrent ();
+		      return count;
+		    }
+		  grouplist[count] = grp->gr_gid;
+		}
+	      count++;
+	      if (count < 0)
+		{
+		  errno = EOVERFLOW;
+		  return -1;
+		}
+	    }
+	}
+    }
+  endgrent ();
+
+  return count;
+}