X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fdmesg.c;h=b7b2c69241894f44741a814450e59793d013a85d;hb=29516ac0e41fc41dd15b7d0c67bd160f03d21bbb;hp=2ca882714cd4cde9ac5f3f31735f62804d7c8dac;hpb=c7bda1ce659294d6e22c06e087f6f265983c7578;p=oweals%2Fbusybox.git diff --git a/util-linux/dmesg.c b/util-linux/dmesg.c index 2ca882714..b7b2c6924 100644 --- a/util-linux/dmesg.c +++ b/util-linux/dmesg.c @@ -1,99 +1,124 @@ /* 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 - * - added Native Language Support +/* * - * from util-linux -- adapted for busybox by - * Erik Andersen . 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 + * Copyright 2006 Rob Landley + * Copyright 2006 Bernhard Reutner-Fischer + * + * Licensed under GPLv2, see file LICENSE in this source tree. */ +//config:config DMESG +//config: bool "dmesg" +//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 dmesg 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) -#include -#include -#include -#include -#include +//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 "busybox.h" +#include +#include "libbb.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) { - char *buf -#ifdef CONFIG_FEATURE_CLEAN_UP - = NULL -#endif - ; - int bufsize = 8196; - int i, n; - int level = 0; - int lastc; - int cmd = 3; + int len, level; + char *buf; + unsigned opts; + enum { + OPT_c = 1 << 0, + OPT_s = 1 << 1, + OPT_n = 1 << 2, + OPT_r = 1 << 3 + }; - 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(); - } + 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 (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; + + 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 (cmd == 8) { - if (klogctl(cmd, NULL, level) < 0) - goto die_the_death; - goto all_done; - } - buf = xmalloc(bufsize); - if ((n = klogctl(cmd, buf, bufsize)) < 0) - goto die_the_death; + if (ENABLE_FEATURE_DMESG_PRETTY && !(opts & OPT_r)) { + int last = '\n'; + int in = 0; - 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++; + /* 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; } - lastc = buf[i]; - putchar(lastc); - } - if (lastc != '\n') - putchar('\n'); -all_done: -#ifdef CONFIG_FEATURE_CLEAN_UP - if (buf) { - free(buf); + /* 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'); } -#endif + + if (ENABLE_FEATURE_CLEAN_UP) free(buf); + return EXIT_SUCCESS; -die_the_death: - bb_perror_nomsg_and_die(); }