InfoMagic Internet Tools 1993 July/Internet Tools.iso/RockRidge/mail/mmdf/libz/zdump.c

C/C++ Source or Header | 1989-09-10 | 4.6 KB | 218 lines

#

#include "stdio.h"

#ifndef lint
#ifndef NOID
static char    sccsid[] = "@(#)zdump.c    3.1";
#endif /* !NOID */
#endif /* !lint */

#include "sys/types.h"
#include "time.h"
#include "tzfile.h"

#ifndef TRUE
#define TRUE        1
#define FALSE        0
#endif

extern char *        asctime();
extern char **        environ;
extern struct tm *    gmtime();
extern char *        imalloc();
extern char *        optarg;
extern int        optind;
#if defined(USG) || defined(SYS5)    /* Added SYS5. ECB 10/88 */
extern char *        sprintf();
#endif /* !USG */
extern long        time();
extern char *        tzname[2];
extern void        tzset();

/*
** For the benefit of cyntax...
*/

static long        tzdecode();
static            readerr();
static            show();

static int        longest;

static long
tzdecode(codep)
char *    codep;
{
    register int    i;
    register long    result;

    result = 0;
    for (i = 0; i < 4; ++i)
        result = (result << 8) | (codep[i] & 0xff);
    return result;
}

main(argc, argv)
int    argc;
char *    argv[];
{
    register FILE *    fp;
    register int    i, j, c;
    register int    vflag;
    register char *    cutoff;
    register int    cutyear;
    register long    cuttime;
    time_t        now;
    time_t        t;
    long        timecnt;
    char        buf[BUFSIZ];

    vflag = 0;
    cutoff = NULL;
    while ((c = getopt(argc, argv, "c:v")) == 'c' || c == 'v')
        if (c == 'v')
            vflag = 1;
        else    cutoff = optarg;
    if (c != EOF || optind == argc - 1 && strcmp(argv[optind], "=") == 0) {
        (void) fprintf(stderr, "%s: usage is %s [ -v ] zonename ...\n",
            argv[0], argv[0]);
        exit(1);
    }
    if (cutoff != NULL)
        cutyear = atoi(cutoff);
    /*
    ** VERY approximate.
    */
    cuttime = (long) (cutyear - EPOCH_YEAR) *
        SECS_PER_HOUR * HOURS_PER_DAY * DAYS_PER_NYEAR;
    (void) time(&now);
    longest = 0;
    for (i = optind; i < argc; ++i)
        if (strlen(argv[i]) > longest)
            longest = strlen(argv[i]);
    for (i = optind; i < argc; ++i) {
        register char **    saveenv;
        char *            tzequals;
        char *            fakeenv[2];

        tzequals = imalloc(strlen(argv[i]) + 4);
        if (tzequals == NULL) {
            (void) fprintf(stderr, "%s: can't allocate memory\n",
                argv[0]);
            exit(1);
        }
        (void) sprintf(tzequals, "TZ=%s", argv[i]);
        fakeenv[0] = tzequals;
        fakeenv[1] = NULL;
        saveenv = environ;
        environ = fakeenv;
        (void) tzset();
        environ = saveenv;
        show(argv[i], now, FALSE);
        if (!vflag)
            continue;
        if (argv[i][0] == '/')
            fp = fopen(argv[i], "r");
        else {
            j = strlen(TZDIR) + 1 + strlen(argv[i]) + 1;
            if (j > sizeof buf) {
                (void) fprintf(stderr,
                    "%s: timezone name %s/%s is too long\n",
                    argv[0], TZDIR, argv[i]);
                exit(1);
            }
            (void) sprintf(buf, "%s/%s", TZDIR, argv[i]);
            fp = fopen(buf, "r");
        }
        if (fp == NULL) {
            (void) fprintf(stderr, "%s: Can't open ", argv[0]);
            perror(argv[i]);
            exit(1);
        }
        {
            char        code[4];

(void) fseek(fp, (long) sizeof ((struct tzhead *) 0)->tzh_reserved, 0);
            if (fread((char *) code, sizeof code, 1, fp) != 1)
                readerr(fp, argv[0], argv[i]);
            timecnt = tzdecode(code);
            (void) fseek(fp, (long) (2 * sizeof code), 1);
        }
        t = 0x80000000;
        if (t > 0)        /* time_t is unsigned */
            t = 0;
        show(argv[i], t, TRUE);
        t += SECS_PER_HOUR * HOURS_PER_DAY;
        show(argv[i], t, TRUE);
        while (timecnt-- > 0) {
            char    code[4];

            if (fread((char *) code, sizeof code, 1, fp) != 1)
                readerr(fp, argv[0], argv[i]);
            t = tzdecode(code);
            if (cutoff != NULL && t > cuttime)
                break;
            show(argv[i], t - 1, TRUE);
            show(argv[i], t, TRUE);
        }
        if (fclose(fp)) {
            (void) fprintf(stderr, "%s: Error closing ", argv[0]);
            perror(argv[i]);
            exit(1);
        }
        t = 0xffffffff;
        if (t < 0)        /* time_t is signed */
            t = 0x7fffffff ;
        t -= SECS_PER_HOUR * HOURS_PER_DAY;
        show(argv[i], t, TRUE);
        t += SECS_PER_HOUR * HOURS_PER_DAY;
        show(argv[i], t, TRUE);
        free(tzequals);
    }
    if (fflush(stdout) || ferror(stdout)) {
        (void) fprintf(stderr, "%s: Error writing standard output ",
            argv[0]);
        perror("standard output");
        exit(1);
    }
    return 0;
}

static
show(zone, t, v)
char *    zone;
time_t    t;
{
    struct tm *        tmp;
    extern struct tm *    localtime();

    (void) printf("%-*s  ", longest, zone);
    if (v)
        (void) printf("%.24s GMT = ", asctime(gmtime(&t)));
    tmp = localtime(&t);
    (void) printf("%.24s", asctime(tmp));
    if (*tzname[tmp->tm_isdst] != '\0')
        (void) printf(" %s", tzname[tmp->tm_isdst]);
    if (v) {
        (void) printf(" isdst=%d", tmp->tm_isdst);
#ifdef KRE_COMPAT
        (void) printf(" gmtoff=%ld", tmp->tm_gmtoff);
#endif /* KRE_COMPAT */
    }
    (void) printf("\n");
}

static
readerr(fp, progname, filename)
FILE *    fp;
char *    progname;
char *    filename;
{
    (void) fprintf(stderr, "%s: Error reading ", progname);
    if (ferror(fp))
        perror(filename);
    else    (void) fprintf(stderr, "%s: Premature EOF\n", filename);
    exit(1);
}