1 /* $OpenBSD: ctime.c,v 1.2 1998/06/11 01:34:10 mickey Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Michael Shalayeff 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Michael Shalayeff. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/time.h> 34 #include "stand.h" 35 36 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 37 38 char * 39 ctime(clock) 40 const time_t *clock; 41 { 42 static const char wdays[][4] = { 43 "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" 44 }; 45 static const char months[][4] = { 46 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 47 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 48 }; 49 static const u_int monthcnt[] = { 50 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 51 }; 52 static char buf[64]; 53 int ss, mm, hh, wday, month, year; 54 register time_t tt = *clock; 55 56 ss = tt % 60; 57 tt /= 60; /* minutes */ 58 mm = tt % 60; 59 tt /= 60; /* hours */ 60 hh = tt % 24; 61 tt /= 24; /* days */ 62 wday = (4 + tt) % 7; /* weekday, 'twas thursday when time started */ 63 64 for (year = 1970; tt >= 365; year++) 65 tt -= isleap(year)? 366: 365; 66 67 tt++; /* days are 1-based */ 68 69 for (month = 0; tt > monthcnt[month]; month++) 70 tt -= monthcnt[month]; 71 72 if (month > 2 && isleap(year)) 73 tt--; 74 75 /* no field widths in printf() */ 76 sprintf(buf, "%s %s %d %d:%d:%d %d\n", 77 ((wday < 0 || wday >= 7)? "???": wdays[wday]), 78 ((month < 0 || month >= 12)? "???": months[month]), 79 (int)tt, hh, mm, ss, year); 80 return buf; 81 } 82