summaryrefslogtreecommitdiff
path: root/miscutils/dutmp.c
diff options
context:
space:
mode:
Diffstat (limited to 'miscutils/dutmp.c')
-rw-r--r--miscutils/dutmp.c95
1 files changed, 57 insertions, 38 deletions
diff --git a/miscutils/dutmp.c b/miscutils/dutmp.c
index 19e09fb..113f850 100644
--- 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>
-#include <errno.h>
-#include <utmp.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 <stdlib.h>
#include <unistd.h>
-#include <time.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) {
- error_msg_and_die(io_error, argv[1]);
- }
+ if (argc > 2) {
+ bb_show_usage();
+ }
+ ++argv;
+ if ((argc == 2) && ((argv[0][0] != '-') || argv[0][1])) {
+ file = bb_xopen(*argv, O_RDONLY);
}
-/* Kludge around the fact that the binary format for utmp has changed. */
+
+ 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 */
- 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);
- }
+ /* 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);
}