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 aa26f5836c7e9c6e6b319d875c84920a96d614dc..06a03d3fb76af17c29b101ca56a87de0bdd9feae 100644 (file)
--- a/util-linux/dmesg.c
+++ b/util-linux/dmesg.c
@@ -1,116 +1,73 @@
-/* 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
+/* vi: set sw=4 ts=4: */
+/*
  *
- * from util-linux -- adapted for busybox by 
- * Erik Andersen <andersee@debian.org>. I ripped out Native Language 
- * Support, replaced getopt, added some gotos for redundant stuff.
+ * dmesg - display/control kernel ring buffer.
+ *
+ * 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 <sys/klog.h>
+#include "libbb.h"
 
-#include "internal.h"
-#include <linux/unistd.h>
-#include <stdio.h>
-#include <getopt.h>
-#include <stdlib.h>
-
-#if __GNU_LIBRARY__ < 5
-
-#ifndef __alpha__
-# define __NR_klogctl __NR_syslog
-  static inline _syscall3(int, klogctl, int, type, char *, b, int, len);
-#else /* __alpha__ */
-#define klogctl syslog
-#endif
+int dmesg_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int dmesg_main(int argc UNUSED_PARAM, char **argv)
+{
+       int len, level;
+       char *buf;
+       unsigned opts;
+       enum {
+               OPT_c = 1 << 0,
+               OPT_s = 1 << 1,
+               OPT_n = 1 << 2
+       };
 
-#else
-# include <sys/klog.h>
-#endif
+       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;
+       }
 
-static const char dmesg_usage[] = "dmesg [-c] [-n level] [-s bufsize]\n";
+       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;
 
-int dmesg_main( int argc, char** argv )
-{
-   char *buf;
-   int bufsize=8196;
-   int  i;
-   int  n;
-   int  level = 0;
-   int  lastc;
-   int  cmd = 3;
+       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;
 
-    /* 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;
-           case 's':
-               if (--argc == 0)
-                   goto end;
-               bufsize = atoi (*(++argv));
-               --argc;
-               ++argv;
-               break;
-           default:
-               goto end;
-           }
-    }
-   
-   if (argc > 1) {
-       goto end;
-   }
+       /* Skip <#> at the start of lines, and make sure we end with a newline */
 
-   if (cmd == 8) {
-      n = klogctl( cmd, NULL, level );
-      if (n < 0) {
-         goto klogctl_error;
-      }
-      exit( TRUE );
-   }
+       if (ENABLE_FEATURE_DMESG_PRETTY) {
+               int last = '\n';
+               int in = 0;
 
-   if (bufsize < 4096) bufsize = 4096;
-   buf = (char*)malloc(bufsize);
-   n = klogctl( cmd, buf, bufsize );
-   if (n < 0) {
-       goto klogctl_error;
-   }
+               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');
+       }
 
-   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++;
-      }
-      lastc = buf[i];
-      putchar( lastc );
-   }
-   if (lastc != '\n')
-      putchar( '\n' );
-   exit( TRUE);
-end:
-    usage( dmesg_usage);
-    exit (FALSE);
-klogctl_error:
-    perror( "klogctl" );
-    exit( FALSE );
+       if (ENABLE_FEATURE_CLEAN_UP) free(buf);
 
+       return EXIT_SUCCESS;
 }