source: MondoRescue/branches/3.2/mindi-busybox/miscutils/last_fancy.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * (sysvinit like) last implementation
 *
 * Copyright (C) 2008 by Patricia Muscalu <patricia.muscalu@axis.com>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"

/* NB: ut_name and ut_user are the same field, use only one name (ut_user)
 * to reduce confusion */

#ifndef SHUTDOWN_TIME
#  define SHUTDOWN_TIME 254
#endif

#define HEADER_FORMAT     "%-8.8s %-12.12s %-*.*s %-16.16s %-7.7s %s\n"
#define HEADER_LINE       "USER", "TTY", \
    INET_ADDRSTRLEN, INET_ADDRSTRLEN, "HOST", "LOGIN", "  TIME", ""
#define HEADER_LINE_WIDE  "USER", "TTY", \
    INET6_ADDRSTRLEN, INET6_ADDRSTRLEN, "HOST", "LOGIN", "  TIME", ""

enum {
    NORMAL,
    LOGGED,
    DOWN,
    REBOOT,
    CRASH,
    GONE
};

enum {
    LAST_OPT_W = (1 << 0),  /* -W wide            */
    LAST_OPT_f = (1 << 1),  /* -f input file      */
    LAST_OPT_H = (1 << 2),  /* -H header          */
};

#define show_wide (option_mask32 & LAST_OPT_W)

static void show_entry(struct utmp *ut, int state, time_t dur_secs)
{
    unsigned days, hours, mins;
    char duration[32];
    char login_time[17];
    char logout_time[8];
    const char *logout_str;
    const char *duration_str;
    time_t tmp;

    /* manpages say ut_tv.tv_sec *is* time_t,
     * but some systems have it wrong */
    tmp = ut->ut_tv.tv_sec;
    safe_strncpy(login_time, ctime(&tmp), 17);
    snprintf(logout_time, 8, "- %s", ctime(&dur_secs) + 11);

    dur_secs = MAX(dur_secs - (time_t)ut->ut_tv.tv_sec, (time_t)0);
    /* unsigned int is easier to divide than time_t (which may be signed long) */
    mins = dur_secs / 60;
    days = mins / (24*60);
    mins = mins % (24*60);
    hours = mins / 60;
    mins = mins % 60;

//  if (days) {
        sprintf(duration, "(%u+%02u:%02u)", days, hours, mins);
//  } else {
//      sprintf(duration, " (%02u:%02u)", hours, mins);
//  }

    logout_str = logout_time;
    duration_str = duration;
    switch (state) {
    case NORMAL:
        break;
    case LOGGED:
        logout_str = "  still";
        duration_str = "logged in";
        break;
    case DOWN:
        logout_str = "- down ";
        break;
    case REBOOT:
        break;
    case CRASH:
        logout_str = "- crash";
        break;
    case GONE:
        logout_str = "   gone";
        duration_str = "- no logout";
        break;
    }

    printf(HEADER_FORMAT,
        ut->ut_user,
        ut->ut_line,
        show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
        show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
        ut->ut_host,
        login_time,
        logout_str,
        duration_str);
}

static int get_ut_type(struct utmp *ut)
{
    if (ut->ut_line[0] == '~') {
        if (strcmp(ut->ut_user, "shutdown") == 0) {
            return SHUTDOWN_TIME;
        }
        if (strcmp(ut->ut_user, "reboot") == 0) {
            return BOOT_TIME;
        }
        if (strcmp(ut->ut_user, "runlevel") == 0) {
            return RUN_LVL;
        }
        return ut->ut_type;
    }

    if (ut->ut_user[0] == 0) {
        return DEAD_PROCESS;
    }

    if ((ut->ut_type != DEAD_PROCESS)
     && (strcmp(ut->ut_user, "LOGIN") != 0)
     && ut->ut_user[0]
     && ut->ut_line[0]
    ) {
        ut->ut_type = USER_PROCESS;
    }

    if (strcmp(ut->ut_user, "date") == 0) {
        if (ut->ut_line[0] == '|') {
            return OLD_TIME;
        }
        if (ut->ut_line[0] == '{') {
            return NEW_TIME;
        }
    }
    return ut->ut_type;
}

static int is_runlevel_shutdown(struct utmp *ut)
{
    if (((ut->ut_pid & 255) == '0') || ((ut->ut_pid & 255) == '6')) {
        return 1;
    }

    return 0;
}

int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int last_main(int argc UNUSED_PARAM, char **argv)
{
    struct utmp ut;
    const char *filename = _PATH_WTMP;
    llist_t *zlist;
    off_t pos;
    time_t start_time;
    time_t boot_time;
    time_t down_time;
    int file;
    smallint going_down;
    smallint boot_down;

    /*opt =*/ getopt32(argv, "Wf:" /* "H" */, &filename);
#ifdef BUT_UTIL_LINUX_LAST_HAS_NO_SUCH_OPT
    if (opt & LAST_OPT_H) {
        /* Print header line */
        if (opt & LAST_OPT_W) {
            printf(HEADER_FORMAT, HEADER_LINE_WIDE);
        } else {
            printf(HEADER_FORMAT, HEADER_LINE);
        }
    }
#endif

    file = xopen(filename, O_RDONLY);
    {
        /* in case the file is empty... */
        struct stat st;
        fstat(file, &st);
        start_time = st.st_ctime;
    }

    time(&down_time);
    going_down = 0;
    boot_down = NORMAL; /* 0 */
    zlist = NULL;
    boot_time = 0;
    /* get file size, rounding down to last full record */
    pos = xlseek(file, 0, SEEK_END) / sizeof(ut) * sizeof(ut);
    for (;;) {
        pos -= (off_t)sizeof(ut);
        if (pos < 0) {
            /* Beyond the beginning of the file boundary =>
             * the whole file has been read. */
            break;
        }
        xlseek(file, pos, SEEK_SET);
        xread(file, &ut, sizeof(ut));
        /* rewritten by each record, eventially will have
         * first record's ut_tv.tv_sec: */
        start_time = ut.ut_tv.tv_sec;

        switch (get_ut_type(&ut)) {
        case SHUTDOWN_TIME:
            down_time = ut.ut_tv.tv_sec;
            boot_down = DOWN;
            going_down = 1;
            break;
        case RUN_LVL:
            if (is_runlevel_shutdown(&ut)) {
                down_time = ut.ut_tv.tv_sec;
                going_down = 1;
                boot_down = DOWN;
            }
            break;
        case BOOT_TIME:
            strcpy(ut.ut_line, "system boot");
            show_entry(&ut, REBOOT, down_time);
            boot_down = CRASH;
            going_down = 1;
            break;
        case DEAD_PROCESS:
            if (!ut.ut_line[0]) {
                break;
            }
            /* add_entry */
            llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
            break;
        case USER_PROCESS: {
            int show;

            if (!ut.ut_line[0]) {
                break;
            }
            /* find_entry */
            show = 1;
            {
                llist_t *el, *next;
                for (el = zlist; el; el = next) {
                    struct utmp *up = (struct utmp *)el->data;
                    next = el->link;
                    if (strncmp(up->ut_line, ut.ut_line, UT_LINESIZE) == 0) {
                        if (show) {
                            show_entry(&ut, NORMAL, up->ut_tv.tv_sec);
                            show = 0;
                        }
                        llist_unlink(&zlist, el);
                        free(el->data);
                        free(el);
                    }
                }
            }

            if (show) {
                int state = boot_down;

                if (boot_time == 0) {
                    state = LOGGED;
                    /* Check if the process is alive */
                    if ((ut.ut_pid > 0)
                     && (kill(ut.ut_pid, 0) != 0)
                     && (errno == ESRCH)) {
                        state = GONE;
                    }
                }
                show_entry(&ut, state, boot_time);
            }
            /* add_entry */
            llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
            break;
        }
        }

        if (going_down) {
            boot_time = ut.ut_tv.tv_sec;
            llist_free(zlist, free);
            zlist = NULL;
            going_down = 0;
        }
    }

    if (ENABLE_FEATURE_CLEAN_UP) {
        llist_free(zlist, free);
    }

    printf("\nwtmp begins %s", ctime(&start_time));

    if (ENABLE_FEATURE_CLEAN_UP)
        close(file);
    fflush_stdout_and_exit(EXIT_SUCCESS);
}