iPatch from waldi, fixes usage of ip route flush (from)? (match|exact)

[oweals/busybox.git] / miscutils / dutmp.c

diff --git a/miscutils/dutmp.c b/miscutils/dutmp.c
index df7f64d30dfaaff27a573443263d7a57e5b618c5..113f850fed7f32c1100d25693da381cfcc432ffe 100644 (file)
--- a/miscutils/dutmp.c
+++ b/miscutils/dutmp.c
@@ -8,57 +8,76 @@
  * versions of 'who', 'last', etc. IP Addr is output in hex, 
  * little endian on x86.
  * 
- * Modified to support all sorts of libcs by 
- * Erik Andersen <andersen@lineo.com>
  */
 
-#include <sys/types.h>
-#include <fcntl.h>
+/* Mar 13, 2003       Manuel Novoa III
+ *
+ * 1) Added proper error checking.
+ * 2) Allow '-' arg for stdin.
+ * 3) For modern libcs, take into account that utmp char[] members
+ *    need not be nul-terminated.
+ */
 
-#include <errno.h>
-#include <utmp.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <utmp.h>
 #include "busybox.h"
 
+/* Grr... utmp char[] members  do not have to be nul-terminated.
+ * Do what we can while still keeping this reasonably small.
+ * Note: We are assuming the ut_id[] size is fixed at 4. */
+
+#if __GNU_LIBRARY__ < 5
+#warning the format string needs to be changed
+#else
+#if (UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE != 256)
+#error struct utmp member char[] size(s) have changed!
+#endif
+#endif
+
 extern int dutmp_main(int argc, char **argv)
 {
-
-       int file;
+       int file = STDIN_FILENO;
+       ssize_t n;
        struct utmp ut;
 
-       if (argc<2) {
-               file = fileno(stdin);
-       } else if (*argv[1] == '-' ) {
-               show_usage();
-       } else  {
-               file = open(argv[1], O_RDONLY);
-               if (file < 0) {
-                       perror_msg_and_die(io_error, argv[1]);
-               }
+       if (argc > 2) {
+               bb_show_usage();
        }
-
-/* Kludge around the fact that the binary format for utmp has changed. */
-#if __GNU_LIBRARY__ < 5 || defined __UCLIBC__
-       /* Linux libc5 */
-       while (read(file, (void*)&ut, sizeof(struct utmp))) {
-               printf("%d|%d|%s|%s|%s|%s|%s|%lx\n",
-                               ut.ut_type, ut.ut_pid, ut.ut_line,
-                               ut.ut_id, ut.ut_user, ut.ut_host,
-                               ctime(&(ut.ut_time)), 
-                               (long)ut.ut_addr);
+       ++argv;
+       if ((argc == 2) && ((argv[0][0] != '-') || argv[0][1])) {
+               file = bb_xopen(*argv, O_RDONLY);
        }
+
+
+       while ((n = safe_read(file, (void*)&ut, sizeof(struct utmp))) != 0) {
+
+               if (n != sizeof(struct utmp)) {
+                       bb_perror_msg_and_die("short read");
+               }
+
+               /* Kludge around the fact that the binary format for utmp has changed. */
+#if __GNU_LIBRARY__ < 5
+               /* Linux libc5 */
+
+               bb_printf("%d|%d|%s|%s|%s|%s|%s|%lx\n",
+                                 ut.ut_type, ut.ut_pid, ut.ut_line,
+                                 ut.ut_id, ut.ut_user, ut.ut_host,
+                                 ctime(&(ut.ut_time)), 
+                                 (long)ut.ut_addr);
 #else
-       /* Glibc, uClibc, etc. */
-       while (read(file, (void*)&ut, sizeof(struct utmp))) {
-               printf("%d|%d|%s|%s|%s|%s|%d|%d|%ld|%ld|%ld|%x\n",
-               ut.ut_type, ut.ut_pid, ut.ut_line,
-               ut.ut_id, ut.ut_user,   ut.ut_host,
-               ut.ut_exit.e_termination, ut.ut_exit.e_exit,
-               ut.ut_session,
-               ut.ut_tv.tv_sec, ut.ut_tv.tv_usec,
-               ut.ut_addr);
-       }
+               /* Glibc, uClibc, etc. */
+
+               bb_printf("%d|%d|%.32s|%.4s|%.32s|%.256s|%d|%d|%ld|%ld|%ld|%x\n",
+                                 ut.ut_type, ut.ut_pid, ut.ut_line,
+                                 ut.ut_id, ut.ut_user, ut.ut_host,
+                                 ut.ut_exit.e_termination, ut.ut_exit.e_exit,
+                                 ut.ut_session,
+                                 ut.ut_tv.tv_sec, ut.ut_tv.tv_usec,
+                                 ut.ut_addr);
 #endif
-       return EXIT_SUCCESS;
+       }
+
+       bb_fflush_stdout_and_exit(EXIT_SUCCESS);
 }