/*
 * Copyright (c) 1998,2001 by Sun Microsystems, Inc.
 * All rights reserved.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#include <sys/types.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
/*
 * Convert a ctime(3) format string into a system format date.
 * Return the date thus calculated.
 *
 * Return -1 if the string is not in ctime format.
 */

/*
 * Offsets into the ctime string to various parts.
 */

#define E_MONTH         4
#define E_DAY           8
#define E_HOUR          11
#define E_MINUTE        14
#define E_SECOND        17
#define E_YEAR          20

#ifdef __STDC__
static int lookup(char *);
static time_t emitl(struct tm *);
#else
static int lookup();
static time_t emitl();
#endif

time_t
unctime(str)
        char *str;
{
        struct tm then;
        char dbuf[30];

        /* Definition of ctime(3) is 24 characters + newline + NUL */
        (void) strncpy(dbuf, str, 24);
        dbuf[24] = '\0';
        dbuf[E_MONTH+3] = '\0';
        then.tm_mon = lookup(&dbuf[E_MONTH]);
        if (then.tm_mon < 0) {
                return (-1);
        }
        then.tm_mday = atoi(&dbuf[E_DAY]);
        then.tm_hour = atoi(&dbuf[E_HOUR]);
        then.tm_min = atoi(&dbuf[E_MINUTE]);
        then.tm_sec = atoi(&dbuf[E_SECOND]);
        then.tm_year = atoi(&dbuf[E_YEAR]) - 1900;
        return (emitl(&then));
}

static char months[] =
        "JanFebMarAprMayJunJulAugSepOctNovDec";

static int
lookup(str)
        char *str;
{
        char *cp, *cp2;

        for (cp = months, cp2 = str; *cp != 0; cp += 3)
                if (strncmp(cp, cp2, 3) == 0)
                        /* LINTED ptr arith will give < INT_MAX result */
                        return (((int)(cp-months)) / 3);
        return (-1);
}
/*
 * Routine to convert a localtime(3) format date back into
 * a system format date.
 */
static time_t
emitl(dp)
        struct tm *dp;
{
        dp->tm_isdst = -1;
        return (mktime(dp));
}