mirror of
https://git.busybox.net/busybox.git
synced 2024-11-27 07:33:26 +08:00
72089cf6b4
Those two spaces after tab have no effect, and always a nuisance when editing. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
125 lines
3.4 KiB
C
125 lines
3.4 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
*
|
|
* 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.
|
|
*/
|
|
//config:config DMESG
|
|
//config: bool "dmesg (3.5 kb)"
|
|
//config: default y
|
|
//config: select PLATFORM_LINUX
|
|
//config: help
|
|
//config: dmesg is used to examine or control the kernel ring buffer. When the
|
|
//config: Linux kernel prints messages to the system log, they are stored in
|
|
//config: the kernel ring buffer. You can use dmesg to print the kernel's ring
|
|
//config: buffer, clear the kernel ring buffer, change the size of the kernel
|
|
//config: ring buffer, and change the priority level at which kernel messages
|
|
//config: are also logged to the system console. Enable this option if you
|
|
//config: wish to enable the 'dmesg' utility.
|
|
//config:
|
|
//config:config FEATURE_DMESG_PRETTY
|
|
//config: bool "Pretty output"
|
|
//config: default y
|
|
//config: depends on DMESG
|
|
//config: help
|
|
//config: If you wish to scrub the syslog level from the output, say 'Y' here.
|
|
//config: The syslog level is a string prefixed to every line with the form
|
|
//config: "<#>".
|
|
//config:
|
|
//config: With this option you will see:
|
|
//config: # dmesg
|
|
//config: Linux version 2.6.17.4 .....
|
|
//config: BIOS-provided physical RAM map:
|
|
//config: BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
|
|
//config:
|
|
//config: Without this option you will see:
|
|
//config: # dmesg
|
|
//config: <5>Linux version 2.6.17.4 .....
|
|
//config: <6>BIOS-provided physical RAM map:
|
|
//config: <6> BIOS-e820: 0000000000000000 - 000000000009f000 (usable)
|
|
|
|
//applet:IF_DMESG(APPLET(dmesg, BB_DIR_BIN, BB_SUID_DROP))
|
|
|
|
//kbuild:lib-$(CONFIG_DMESG) += dmesg.o
|
|
|
|
//usage:#define dmesg_trivial_usage
|
|
//usage: "[-c] [-n LEVEL] [-s SIZE]"
|
|
//usage:#define dmesg_full_usage "\n\n"
|
|
//usage: "Print or control the kernel ring buffer\n"
|
|
//usage: "\n -c Clear ring buffer after printing"
|
|
//usage: "\n -n LEVEL Set console logging level"
|
|
//usage: "\n -s SIZE Buffer size"
|
|
//usage: "\n -r Print raw message buffer"
|
|
|
|
#include <sys/klog.h>
|
|
#include "libbb.h"
|
|
|
|
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,
|
|
OPT_r = 1 << 3
|
|
};
|
|
|
|
opts = getopt32(argv, "cs:+n:+r", &len, &level);
|
|
if (opts & OPT_n) {
|
|
if (klogctl(8, NULL, (long) level))
|
|
bb_perror_msg_and_die("klogctl");
|
|
return EXIT_SUCCESS;
|
|
}
|
|
|
|
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;
|
|
|
|
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;
|
|
|
|
|
|
if (ENABLE_FEATURE_DMESG_PRETTY && !(opts & OPT_r)) {
|
|
int last = '\n';
|
|
int in = 0;
|
|
|
|
/* Skip <[0-9]+> at the start of lines */
|
|
while (1) {
|
|
if (last == '\n' && buf[in] == '<') {
|
|
while (buf[in++] != '>' && in < len)
|
|
;
|
|
} else {
|
|
last = buf[in++];
|
|
putchar(last);
|
|
}
|
|
if (in >= len)
|
|
break;
|
|
}
|
|
/* Make sure we end with a newline */
|
|
if (last != '\n')
|
|
bb_putchar('\n');
|
|
} else {
|
|
full_write(STDOUT_FILENO, buf, len);
|
|
if (buf[len-1] != '\n')
|
|
bb_putchar('\n');
|
|
}
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP) free(buf);
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|