made 3 license strings to follow the usual form ("or later" bit is not changed!)

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

diff --git a/util-linux/dmesg.c b/util-linux/dmesg.c
index 0c0d2d7c0a0c190d8ab55fa547f97553f59f9984..06a03d3fb76af17c29b101ca56a87de0bdd9feae 100644 (file)
--- a/util-linux/dmesg.c
+++ b/util-linux/dmesg.c
@@ -1,95 +1,73 @@
 /* vi: set sw=4 ts=4: */
-/* 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)
- * Larger buffersize 3 June 1998 by Nicolai Langfeldt, based on a patch
- * by Peeter Joot.  This was also suggested by John Hudson.
- * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org>
- * - added Native Language Support
+/*
  *
- * from util-linux -- adapted for busybox by 
- * Erik Andersen <andersen@codepoet.org>. I ripped out Native Language 
- * Support, replaced getopt, added some gotos for redundant stuff.
+ * dmesg - display/control kernel ring buffer.
  *
- * Audited and cleaned up on 7 March 2003 to reduce size of
- * check error handling by Erik Andersen <andersen@codepoet.org>
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ * Copyright 2006 Bernhard Reutner-Fischer <rep.nop@aon.at>
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <getopt.h>
-#include <errno.h>
 #include <sys/klog.h>
+#include "libbb.h"
 
-#include "busybox.h"
-
-int dmesg_main(int argc, char **argv)
+int dmesg_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int dmesg_main(int argc UNUSED_PARAM, char **argv)
 {
+       int len, level;
        char *buf;
-       int bufsize = 8196;
-       int i, n;
-       int level = 0;
-       int lastc;
-       int cmd = 3;
+       unsigned opts;
+       enum {
+               OPT_c = 1 << 0,
+               OPT_s = 1 << 1,
+               OPT_n = 1 << 2
+       };
 
-       while ((i = getopt(argc, argv, "cn:s:")) > 0) {
-               switch (i) {
-                       case 'c':
-                               cmd = 4;
-                               break;
-                       case 'n':
-                               cmd = 8;
-                               level = bb_xgetlarg(optarg, 10, 0, 10);
-                               break;
-                       case 's':
-                               /* I think a 512k max kernel ring buffer is big enough for
-                                * anybody, as the default is 16k...  Could be wrong though.
-                                * If so I'm sure I'll hear about it by the enraged masses*/
-                               bufsize = bb_xgetlarg(optarg, 10, 4096, 512*1024);
-                               break;
-                       default:
-                               bb_show_usage();
-               }
+       opt_complementary = "s+:n+"; /* numeric */
+       opts = getopt32(argv, "cs:n:", &len, &level);
+       if (opts & OPT_n) {
+               if (klogctl(8, NULL, (long) level))
+                       bb_perror_msg_and_die("klogctl");
+               return EXIT_SUCCESS;
        }
 
-       if (optind < argc) {
-               bb_show_usage();
-       }
+       if (!(opts & OPT_s))
+               len = klogctl(10, NULL, 0); /* read ring buffer size */
+       if (len < 16*1024)
+               len = 16*1024;
+       if (len > 16*1024*1024)
+               len = 16*1024*1024;
 
-       if (cmd == 8) {
-               if (klogctl(cmd, NULL, level) < 0)
-                       goto die_the_death;
-               goto all_done;
-       }
+       buf = xmalloc(len);
+       len = klogctl(3 + (opts & OPT_c), buf, len); /* read ring buffer */
+       if (len < 0)
+               bb_perror_msg_and_die("klogctl");
+       if (len == 0)
+               return EXIT_SUCCESS;
 
-       buf = xmalloc(bufsize);
-       if ((n = klogctl(cmd, buf, bufsize)) < 0)
-               goto die_the_death;
+       /* Skip <#> at the start of lines, and make sure we end with a newline */
 
-       lastc = '\n';
-       for (i = 0; i < n; i++) {
-               if (lastc == '\n' && buf[i] == '<') {
-                       i++;
-                       while (buf[i] >= '0' && buf[i] <= '9')
-                               i++;
-                       if (buf[i] == '>')
-                               i++;
-               }
-               lastc = buf[i];
-               putchar(lastc);
-       }
-       if (lastc != '\n')
-               putchar('\n');
-all_done:
-#ifdef CONFIG_FEATURE_CLEAN_UP
-       if (buf) {
-               free(buf);
+       if (ENABLE_FEATURE_DMESG_PRETTY) {
+               int last = '\n';
+               int in = 0;
+
+               do {
+                       if (last == '\n' && buf[in] == '<')
+                               in += 3;
+                       else {
+                               last = buf[in++];
+                               bb_putchar(last);
+                       }
+               } while (in < len);
+               if (last != '\n')
+                       bb_putchar('\n');
+       } else {
+               full_write(STDOUT_FILENO, buf, len);
+               if (buf[len-1] != '\n')
+                       bb_putchar('\n');
        }
-#endif
+
+       if (ENABLE_FEATURE_CLEAN_UP) free(buf);
+
        return EXIT_SUCCESS;
-die_the_death:
-       bb_perror_nomsg_and_die();
 }