source: MondoRescue/branches/3.3/mindi-busybox/util-linux/dmesg.c@ 3621

/* 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.
 */

//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
    };

    opt_complementary = "s+:n+"; /* numeric */
    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;
}