lslogins: also add readutmp.c

diff --git a/lib/readutmp.c b/lib/readutmp.c
new file mode 100644 (file)
index 0000000..4e8a084
--- /dev/null
+++ b/lib/readutmp.c
@@ -0,0 +1,76 @@
+/* GNU's read utmp module.
+
+        Copyright (C) 1992-2001, 2003-2006, 2009-2014 Free Software Foundation, Inc.
+
+        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 3 of the License, 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, see <http://www.gnu.org/licenses/>.     */
+
+/* Written by jla; revised by djm */
+/* extracted for util-linux by ooprala */
+
+#include <errno.h>
+#include <stdio.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "xalloc.h"
+#include "readutmp.h"
+
+/* Read the utmp entries corresponding to file FILE into freshly-
+        malloc'd storage, set *UTMP_BUF to that pointer, set *N_ENTRIES to
+        the number of entries, and return zero.        If there is any error,
+        return -1, setting errno, and don't modify the parameters.
+        If OPTIONS & READ_UTMP_CHECK_PIDS is nonzero, omit entries whose
+        process-IDs do not currently exist.    */
+int
+read_utmp (char const *file, size_t *n_entries, struct utmp **utmp_buf)
+{
+       size_t n_read = 0;
+       size_t n_alloc = 0;
+       struct utmp *utmp = NULL;
+       struct utmp *u;
+
+       /* Ignore the return value for now.
+                Solaris' utmpname returns 1 upon success -- which is contrary
+                to what the GNU libc version does.     In addition, older GNU libc
+                versions are actually void.     */
+       utmpname(file);
+
+       setutent();
+
+       errno = 0;
+       while ((u = getutent()) != NULL) {
+               if (n_read == n_alloc) {
+                       n_alloc += 32;
+                       utmp = xrealloc(utmp, n_alloc * sizeof (struct utmp));
+                       if (!utmp)
+                               return -1;
+               }
+               utmp[n_read++] = *u;
+       }
+       if (!u && errno)
+               return -1;
+
+       endutent();
+
+       *n_entries = n_read;
+       *utmp_buf = utmp;
+
+       return 0;
+}