create a document for mdev so people dont have to rtfs

[oweals/busybox.git] / util-linux / dmesg.c

diff --git a/util-linux/dmesg.c b/util-linux/dmesg.c
index 64265b473e6049a560f324ae2c70f0067570dbc1..0bbc306fca3f312588529f74f97bc2d29f651e58 100644 (file)
--- a/util-linux/dmesg.c
+++ b/util-linux/dmesg.c
@@ -1,98 +1,54 @@
-#include "internal.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <time.h>
-
-/* dmesg.c -- Print out the contents of the kernel ring buffer
- * Created: Sat Oct  9 16:19:47 1993
- * Revised: Thu Oct 28 21:52:17 1993 by faith@cs.unc.edu
- * Copyright 1993 Theodore Ts'o (tytso@athena.mit.edu)
- * This program comes with ABSOLUTELY NO WARRANTY.
- * Modifications by Rick Sladkey (jrs@world.std.com)
- * from util-linux; adapted for busybox
+/* vi: set sw=4 ts=4: */
+/*
+ *
+ * dmesg - display/control kernel ring buffer.
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ * Copyright 2006 Bernhard Fischer <rep.nop@aon.at>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
  */
 
-#include <linux/unistd.h>
-#include <stdio.h>
-
-#define __NR_klog __NR_syslog
-
-#if defined(__GLIBC__)
+#include "busybox.h"
+#include <unistd.h>
 #include <sys/klog.h>
-#define klog klogctl
-#else
-static inline _syscall3 (int, klog, int, type, char *, b, int, len)
-#endif                         /* __GLIBC__ */
-
-
-
-static const char dmesg_usage[] = "dmesg [-c] [-n level]\n";
 
-int dmesg_main (int argc, char **argv)
+int dmesg_main(int argc, char *argv[]);
+int dmesg_main(int argc, char *argv[])
 {
-
-    char buf[4096];
-    int i;
-    int n;
-    int level = 0;
-    int lastc;
-    int cmd = 3;
-
-    argc--;
-    argv++;
-
-    /* Parse any options */
-    while (argc && **argv == '-') {
-       while (*++(*argv))
-           switch (**argv) {
-           case 'c':
-               cmd = 4;
-               break;
-           case 'n':
-               cmd = 8;
-               if (--argc == 0)
-                   goto end;
-               level = atoi (*(++argv));
-               --argc;
-               ++argv;
-               break;
-           default:
-               goto end;
-           }
-    }
-
-    if (cmd == 8) {
-       n = klog (cmd, NULL, level);
-       if (n < 0) {
-           perror ("klog");
-           exit (FALSE);
-       }
-       exit (TRUE);
-    }
-
-    n = klog (cmd, buf, sizeof (buf));
-    if (n < 0) {
-       perror ("klog");
-       exit (FALSE);
-    }
-
-    lastc = '\n';
-    for (i = 0; i < n; i++) {
-       if ((i == 0 || buf[i - 1] == '\n') && buf[i] == '<') {
-           i++;
-           while (buf[i] >= '0' && buf[i] <= '9')
-               i++;
-           if (buf[i] == '>')
-               i++;
+       char *size, *level;
+       int flags = getopt32(argc, argv, "cs:n:", &size, &level);
+
+       if (flags & 4) {
+               if (klogctl(8, NULL, xatoul_range(level, 0, 10)))
+                       bb_perror_msg_and_die("klogctl");
+       } else {
+               int len;
+               char *buf;
+
+               len = (flags & 2) ? xatoul_range(size, 2, INT_MAX) : 16384;
+               buf = xmalloc(len);
+               if (0 > (len = klogctl(3 + (flags & 1), buf, len)))
+                       bb_perror_msg_and_die("klogctl");
+
+               // Skip <#> at the start of lines, and make sure we end with a newline.
+
+               if (ENABLE_FEATURE_DMESG_PRETTY) {
+                       int last = '\n';
+                       int in;
+
+                       for (in = 0; in<len;) {
+                               if (last == '\n' && buf[in] == '<') in += 3;
+                               else putchar(last = buf[in++]);
+                       }
+                       if (last != '\n') putchar('\n');
+               } else {
+                       write(1,buf,len);
+                       if (len && buf[len-1]!='\n') putchar('\n');
+               }
+
+               if (ENABLE_FEATURE_CLEAN_UP) free(buf);
        }
-       lastc = buf[i];
-       putchar (lastc);
-    }
-    if (lastc != '\n')
-       putchar ('\n');
-    exit (TRUE);
 
-  end:
-    fprintf (stderr, "Usage: %s\n", dmesg_usage);
-    exit (FALSE);
+       return 0;
 }