minix/lib/libc/time/getdate.c

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/* $NetBSD: getdate.c,v 1.2 2009/11/22 18:07:39 mbalmer Exp $ */
/*
* Copyright (c) 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Brian Ginsbach.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <util.h>
#define TMSENTINEL (-1)
/*
* getdate_err is set to one of the following values on error.
*
* 1 The DATEMSK environment variable is null or undefined.
* 2 The template file cannot be opened for reading.
* 3 Failed to get file status information.
* 4 Template file is not a regular file.
* 5 Encountered an error while reading the template file.
* 6 Cannot allocate memory.
* 7 Input string does not match any line in the template.
* 8 Input string is invalid (for example, February 31) or could not
* be represented in a time_t.
*/
int getdate_err;
struct tm *
getdate(const char *str)
{
char *datemsk, *line, *rp;
FILE *fp;
struct stat sb;
static struct tm rtm, tmnow;
struct tm *tmp, *rtmp = &rtm;
size_t lineno = 0;
time_t now;
if (((datemsk = getenv("DATEMSK")) == NULL) || *datemsk == '\0') {
getdate_err = 1;
return (NULL);
}
if (stat(datemsk, &sb) < 0) {
getdate_err = 3;
return (NULL);
}
if ((sb.st_mode & S_IFMT) != S_IFREG) {
getdate_err = 4;
return (NULL);
}
if ((fp = fopen(datemsk, "r")) == NULL) {
getdate_err = 2;
return (NULL);
}
/* loop through datemsk file */
errno = 0;
rp = NULL;
while ((line = fparseln(fp, NULL, &lineno, NULL, 0)) != NULL) {
/* initialize tmp with sentinels */
rtm.tm_sec = rtm.tm_min = rtm.tm_hour = TMSENTINEL;
rtm.tm_mday = rtm.tm_mon = rtm.tm_year = TMSENTINEL;
rtm.tm_wday = rtm.tm_yday = rtm.tm_isdst = TMSENTINEL;
rtm.tm_gmtoff = 0;
rtm.tm_zone = NULL;
rp = strptime(str, line, rtmp);
free(line);
if (rp != NULL)
break;
errno = 0;
}
if (errno != 0 || ferror(fp)) {
if (errno == ENOMEM)
getdate_err = 6;
else
getdate_err = 5;
fclose(fp);
return (NULL);
}
if (feof(fp) || (rp != NULL && *rp != '\0')) {
getdate_err = 7;
return (NULL);
}
fclose(fp);
time(&now);
tmp = localtime(&now);
tmnow = *tmp;
/*
* This implementation does not accept setting the broken-down time
* to anything other than the localtime(). It is not possible to
* change the scanned timezone with %Z.
*
* Note IRIX and Solaris accept only the current zone for %Z.
* XXX Is there any implementation that matches the standard?
* XXX (Or am I reading the standard wrong?)
*
* Note: Neither XPG 6 (POSIX 2004) nor XPG 7 (POSIX 2008)
* requires strptime(3) support for %Z.
*/
/*
* Given only a weekday find the first matching weekday starting
* with the current weekday and moving into the future.
*/
if (rtm.tm_wday != TMSENTINEL && rtm.tm_year == TMSENTINEL &&
rtm.tm_mon == TMSENTINEL && rtm.tm_mday == TMSENTINEL) {
rtm.tm_year = tmnow.tm_year;
rtm.tm_mon = tmnow.tm_mon;
rtm.tm_mday = tmnow.tm_mday +
(rtm.tm_wday - tmnow.tm_wday + 7) % 7;
}
/*
* Given only a month (and no year) find the first matching month
* starting with the current month and moving into the future.
*/
if (rtm.tm_mon != TMSENTINEL) {
if (rtm.tm_year == TMSENTINEL) {
rtm.tm_year = tmnow.tm_year +
((rtm.tm_mon < tmnow.tm_mon)? 1 : 0);
}
if (rtm.tm_mday == TMSENTINEL) {
/* assume the first of the month */
rtm.tm_mday = 1;
/*
* XXX This isn't documented! Just observed behavior.
*
* Given the weekday find the first matching weekday
* starting with the weekday of the first day of the
* the month and moving into the future.
*/
if (rtm.tm_wday != TMSENTINEL) {
struct tm tm;
memset(&tm, 0, sizeof(struct tm));
tm.tm_year = rtm.tm_year;
tm.tm_mon = rtm.tm_mon;
tm.tm_mday = 1;
mktime(&tm);
rtm.tm_mday +=
(rtm.tm_wday - tm.tm_wday + 7) % 7;
}
}
}
/*
* Given no time of day assume the current time of day.
*/
if (rtm.tm_hour == TMSENTINEL &&
rtm.tm_min == TMSENTINEL && rtm.tm_sec == TMSENTINEL) {
rtm.tm_hour = tmnow.tm_hour;
rtm.tm_min = tmnow.tm_min;
rtm.tm_sec = tmnow.tm_sec;
}
/*
* Given an hour and no date, find the first matching hour starting
* with the current hour and moving into the future
*/
if (rtm.tm_hour != TMSENTINEL &&
rtm.tm_year == TMSENTINEL && rtm.tm_mon == TMSENTINEL &&
rtm.tm_mday == TMSENTINEL) {
rtm.tm_year = tmnow.tm_year;
rtm.tm_mon = tmnow.tm_mon;
rtm.tm_mday = tmnow.tm_mday;
if (rtm.tm_hour < tmnow.tm_hour)
rtm.tm_hour += 24;
}
/*
* Set to 'sane' values; mktime(3) does funny things otherwise.
* No hours, no minutes, no seconds, no service.
*/
if (rtm.tm_hour == TMSENTINEL)
rtm.tm_hour = 0;
if (rtm.tm_min == TMSENTINEL)
rtm.tm_min = 0;
if (rtm.tm_sec == TMSENTINEL)
rtm.tm_sec = 0;
/*
* Given only a year the values of month, day of month, day of year,
* week day and is daylight (summer) time are unspecified.
* (Specified on the Solaris man page not POSIX.)
*/
if (rtm.tm_year != TMSENTINEL &&
rtm.tm_mon == TMSENTINEL && rtm.tm_mday == TMSENTINEL) {
rtm.tm_mon = 0;
rtm.tm_mday = 1;
/*
* XXX More undocumented functionality but observed.
*
* Given the weekday find the first matching weekday
* starting with the weekday of the first day of the
* month and moving into the future.
*/
if (rtm.tm_wday != TMSENTINEL) {
struct tm tm;
memset(&tm, 0, sizeof(struct tm));
tm.tm_year = rtm.tm_year;
tm.tm_mon = rtm.tm_mon;
tm.tm_mday = 1;
mktime(&tm);
rtm.tm_mday += (rtm.tm_wday - tm.tm_wday + 7) % 7;
}
}
/*
* Given only the century but no year within, the current year
* is assumed. (Specified on the Solaris man page not POSIX.)
*
* Warning ugly end case
*
* This is more work since strptime(3) doesn't "do the right thing".
*/
if (rtm.tm_year != TMSENTINEL && (rtm.tm_year - 1900) >= 0) {
rtm.tm_year -= 1900;
rtm.tm_year += (tmnow.tm_year % 100);
}
/*
* mktime() will normalize all values and also check that the
* value will fit into a time_t.
*
* This is only for POSIX correctness. A date >= 1900 is
* really ok, but using a time_t limits things.
*/
if (mktime(rtmp) < 0) {
getdate_err = 8;
return (NULL);
}
return (rtmp);
}