BSD 4_3_Tahoe release

[unix-history] / usr / src / old / dump.4.1 / unctime.c

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

#ifndef lint
static char sccsid[] = "@(#)unctime.c   5.1 (Berkeley) 6/5/85";
#endif not lint

#include "include.4.1/sys/types.h"
#include "include.4.1/time.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

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

       if (strlen(str) != 25)
               str[25] = 0;
       strcpy(dbuf, str);
       dbuf[E_MONTH+3] = 0;
       if ( (then.tm_mon = lookup(&dbuf[E_MONTH])) < 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
lookup(str)
       char *str;
{
       register char *cp, *cp2;

       for (cp = months, cp2 = str; *cp != 0; cp += 3)
               if (strncmp(cp, cp2, 3) == 0)
                       return((cp-months) / 3);
       return(-1);
}
/*
* Routine to convert a localtime(3) format date back into
* a system format date.
*
*      Use a binary search.
*/

struct tm *localtime();

time_t emitl(dp)
       struct tm *dp;
{
       time_t conv;
       register int i, bit;
       struct tm dcopy;

       dcopy = *dp;
       dp = &dcopy;
       conv = 0;
       for (i = 31; i >= 0; i--) {
               bit = 1 << i;
               conv |= bit;
               if (dcmp(localtime(&conv), dp) > 0)
                       conv &= ~bit;
       }
       return(conv);
}

/*
* Compare two localtime dates, return result.
*/

#define DECIDE(a) \
       if (dp->a > dp2->a) \
               return(1); \
       if (dp->a < dp2->a) \
               return(-1)

static
dcmp(dp, dp2)
       register struct tm *dp, *dp2;
{

       DECIDE(tm_year);
       DECIDE(tm_mon);
       DECIDE(tm_mday);
       DECIDE(tm_hour);
       DECIDE(tm_min);
       DECIDE(tm_sec);
       return(0);
}