d62
/* Show info in a tz file */

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <time.h>
#include "tzfile.h"

/* convert the bytes of a 32-bit integer to little endian */
#define BSWAP32(c) ((c>>24)&0xff)|((c>>8)&0xff00)|((c<<8)&0xff0000)|(c<<24)

struct tzhead h;
struct ttinfo ti;

int tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt, tzh_timecnt,
    tzh_typecnt, tzh_charcnt;


int read_hdr(int f)
{
    if ((read(f, &h, sizeof(h))) == -1) {
	perror("read");
	return 0;
    }
    tzh_ttisgmtcnt = BSWAP32(*((int *)h.tzh_ttisgmtcnt));
    tzh_ttisstdcnt = BSWAP32(*((int *)h.tzh_ttisstdcnt));
    tzh_leapcnt = BSWAP32(*((int *)h.tzh_leapcnt));
    tzh_timecnt = BSWAP32(*((int *)h.tzh_timecnt));
    tzh_typecnt = BSWAP32(*((int *)h.tzh_typecnt));
    tzh_charcnt = BSWAP32(*((int *)h.tzh_charcnt));

    printf("Header Values\n\n");
    printf("tzh_ttisgmtcnt: %d\n", tzh_ttisgmtcnt);
    printf("tzh_ttisstdcnt: %d\n", tzh_ttisstdcnt);
    printf("tzh_leapcnt: %d\n", tzh_leapcnt);
    printf("tzh_timecnt: %d\n", tzh_timecnt);
    printf("tzh_typecnt: %d\n", tzh_typecnt);
    printf("tzh_charcnt: %d\n", tzh_charcnt);
}

int main(int argc, char **argv)
{
    int f, i;
    char *type_ndx;
    time_t *trans_time;
    struct ttinfo *ti;
    char *abbr;
    char *is_std;
    char *is_gmt;
    int tmp;
    char s[256];
    struct tm *tm;
    char *set_isdst_s[2] = {"No", "Yes"};
    char *std_s[2] = {"Wall", "Std"};
    char *gmt_s[2] = {"Local", "GMT"};

    if (argc == 1) {
	fprintf(stderr, "usage: tzshow <tzfile>\n");
	exit(0);
    }

    if ((f = open(argv[1], O_RDONLY)) == -1) {
	perror("open");
	exit(1);
    }

    if (! read_hdr(f))
	exit(1);

    trans_time = (time_t *)malloc(tzh_timecnt * sizeof(time_t));
    for (i = 0; i < tzh_timecnt; i++) {
	read(f, &tmp, 4);
	trans_time[i] = BSWAP32(tmp);
    }

    type_ndx = (char *)malloc(tzh_timecnt * sizeof(char));
    for (i = 0; i < tzh_timecnt; i++)
	read(f, &(type_ndx[i]), 1);

    ti = (struct ttinfo *)malloc(tzh_typecnt * sizeof(struct ttinfo));
    for (i = 0; i < tzh_typecnt; i++)
	read(f, &(ti[i]), sizeof(struct ttinfo));

    abbr = (char *)malloc(tzh_charcnt);
    read(f, abbr, tzh_charcnt);

    for (i = 0; i < tzh_leapcnt; i++) {
	read(f, &tmp, sizeof(tmp));
	read(f, &tmp, sizeof(tmp));
    }

    is_std = (char *)malloc(tzh_ttisstdcnt * sizeof(char));
    for (i = 0; i < tzh_ttisstdcnt; i++)
	read(f, &(is_std[i]), sizeof(char));

    is_gmt = (char *)malloc(tzh_ttisgmtcnt * sizeof(char));
    for (i = 0; i < tzh_ttisgmtcnt; i++)
	read(f, &(is_gmt[i]), sizeof(char));

    printf("\n\nTransitions\n\n");
    printf("%-30s%s\n\n",  "Date", "Local Time Type");

    for (i = 0; i < tzh_timecnt; i++) {
	tm = gmtime(&(trans_time[i]));
//	strftime(s, 255, "%Y-%m-%d %H:%M", tm);
	strcpy(s, asctime(tm));
	s[strlen(s) - 1] = '\0';
	printf("%-30s%d\n", s, type_ndx[i]);
    }

    printf("\n\nLocal Time Types\n\n");
    printf("%-5s%-10s%-15s%-8s%-12s%s\n\n", "Nr", "GMT Off",
	    "Set tm_isdst", "Abbr", "Std/Wall", "GMT/Local");

    for (i = 0; i < tzh_typecnt; i++) {
	printf("%-5d%-10d%-15s%-8s%-12s%s\n",
		i, (BSWAP32(*((int *)(ti[i].tt_gmtoff)))) / 3600,
		set_isdst_s[ti[i].tt_isdst], abbr + ti[i].tt_abbrind,
		std_s[is_std[i]], gmt_s[is_gmt[i]]);
    }

    close(f);
    return 0;
}
.

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