1 /* vi: set sw=4 ts=4: */
4 * dmesg - display/control kernel ring buffer.
6 * Copyright 2006 Rob Landley <rob@landley.net>
7 * Copyright 2006 Bernhard Reutner-Fischer <rep.nop@aon.at>
9 * Licensed under GPLv2, see file LICENSE in this source tree.
12 //usage:#define dmesg_trivial_usage
13 //usage: "[-c] [-n LEVEL] [-s SIZE]"
14 //usage:#define dmesg_full_usage "\n\n"
15 //usage: "Print or control the kernel ring buffer\n"
16 //usage: "\n -c Clear ring buffer after printing"
17 //usage: "\n -n LEVEL Set console logging level"
18 //usage: "\n -s SIZE Buffer size"
23 int dmesg_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
24 int dmesg_main(int argc UNUSED_PARAM
, char **argv
)
35 opt_complementary
= "s+:n+"; /* numeric */
36 opts
= getopt32(argv
, "cs:n:", &len
, &level
);
38 if (klogctl(8, NULL
, (long) level
))
39 bb_perror_msg_and_die("klogctl");
44 len
= klogctl(10, NULL
, 0); /* read ring buffer size */
47 if (len
> 16*1024*1024)
51 len
= klogctl(3 + (opts
& OPT_c
), buf
, len
); /* read ring buffer */
53 bb_perror_msg_and_die("klogctl");
58 if (ENABLE_FEATURE_DMESG_PRETTY
) {
62 /* Skip <#> at the start of lines */
64 if (last
== '\n' && buf
[in
] == '<') {
75 /* Make sure we end with a newline */
79 full_write(STDOUT_FILENO
, buf
, len
);
80 if (buf
[len
-1] != '\n')
84 if (ENABLE_FEATURE_CLEAN_UP
) free(buf
);