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unctime.c revision 1.3 
      1 /*-
      2  * Copyright (c) 1980 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 static char sccsid[] = "@(#)unctime.c	5.4 (Berkeley) 3/7/91";
     36 static char rcsid[] = "$Header: /tank/opengrok/rsync2/NetBSD/src/sbin/dump/unctime.c,v 1.3 1993/03/23 00:27:23 cgd Exp $";
     37 #endif /* not lint */
     38 
     39 #include <sys/types.h>
     40 #include <time.h>
     41 #include <stdio.h>
     42 #ifdef __STDC__
     43 #include <stdlib.h>
     44 #include <string.h>
     45 #endif
     46 
     47 /*
     48  * Convert a ctime(3) format string into a system format date.
     49  * Return the date thus calculated.
     50  *
     51  * Return -1 if the string is not in ctime format.
     52  */
     53 
     54 /*
     55  * Offsets into the ctime string to various parts.
     56  */
     57 
     58 #define	E_MONTH		4
     59 #define	E_DAY		8
     60 #define	E_HOUR		11
     61 #define	E_MINUTE	14
     62 #define	E_SECOND	17
     63 #define	E_YEAR		20
     64 
     65 static int lookup();
     66 
     67 time_t
     68 unctime(str)
     69 	char *str;
     70 {
     71 	struct tm then;
     72 	char dbuf[30];
     73 	time_t emitl();
     74 
     75 	if (strlen(str) != 25)
     76 		str[25] = 0;
     77 	strcpy(dbuf, str);
     78 	dbuf[E_MONTH+3] = 0;
     79 	if ((then.tm_mon = lookup(&dbuf[E_MONTH])) < 0)
     80 		return (-1);
     81 	then.tm_mday = atoi(&dbuf[E_DAY]);
     82 	then.tm_hour = atoi(&dbuf[E_HOUR]);
     83 	then.tm_min = atoi(&dbuf[E_MINUTE]);
     84 	then.tm_sec = atoi(&dbuf[E_SECOND]);
     85 	then.tm_year = atoi(&dbuf[E_YEAR]) - 1900;
     86 	return(emitl(&then));
     87 }
     88 
     89 static char months[] =
     90 	"JanFebMarAprMayJunJulAugSepOctNovDec";
     91 
     92 static int
     93 lookup(str)
     94 	char *str;
     95 {
     96 	register char *cp, *cp2;
     97 
     98 	for (cp = months, cp2 = str; *cp != 0; cp += 3)
     99 		if (strncmp(cp, cp2, 3) == 0)
    100 			return((cp-months) / 3);
    101 	return(-1);
    102 }
    103 /*
    104  * Routine to convert a localtime(3) format date back into
    105  * a system format date.
    106  *
    107  *	Use a binary search.
    108  */
    109 
    110 struct tm *localtime();
    111 static int dcmp();
    112 
    113 time_t
    114 emitl(dp)
    115 	struct tm *dp;
    116 {
    117 	time_t conv;
    118 	register int i, bit;
    119 	struct tm dcopy;
    120 
    121 	dcopy = *dp;
    122 	dp = &dcopy;
    123 	conv = 0;
    124 	for (i = 30; i >= 0; i--) {
    125 		bit = 1 << i;
    126 		conv |= bit;
    127 		if (dcmp(localtime(&conv), dp) > 0)
    128 			conv &= ~bit;
    129 	}
    130 	return(conv);
    131 }
    132 
    133 /*
    134  * Compare two localtime dates, return result.
    135  */
    136 
    137 #define DECIDE(a) \
    138 	if (dp->a > dp2->a) \
    139 		return(1); \
    140 	if (dp->a < dp2->a) \
    141 		return(-1)
    142 
    143 static int
    144 dcmp(dp, dp2)
    145 	register struct tm *dp, *dp2;
    146 {
    147 
    148 	DECIDE(tm_year);
    149 	DECIDE(tm_mon);
    150 	DECIDE(tm_mday);
    151 	DECIDE(tm_hour);
    152 	DECIDE(tm_min);
    153 	DECIDE(tm_sec);
    154 	return(0);
    155 }
    156