xref: /dragonfly/usr.sbin/pw/psdate.c (revision d4ef6694)
1 /*-
2  * Copyright (C) 1996
3  *	David L. Nugent.  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  *
14  * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/usr.sbin/pw/psdate.c,v 1.8 2004/06/17 14:07:16 robert Exp $
27  */
28 
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <ctype.h>
33 
34 #include "psdate.h"
35 
36 
37 static int
38 a2i(char const ** str)
39 {
40 	int             i = 0;
41 	char const     *s = *str;
42 
43 	if (isdigit((unsigned char)*s)) {
44 		i = atoi(s);
45 		while (isdigit((unsigned char)*s))
46 			++s;
47 		*str = s;
48 	}
49 	return i;
50 }
51 
52 static int
53 numerics(char const * str)
54 {
55 	int             rc = isdigit((unsigned char)*str);
56 
57 	if (rc)
58 		while (isdigit((unsigned char)*str) || *str == 'x')
59 			++str;
60 	return rc && !*str;
61 }
62 
63 static int
64 aindex(char const * arr[], char const ** str, int len)
65 {
66 	int             l, i;
67 	char            mystr[32];
68 
69 	mystr[len] = '\0';
70 	l = strlen(strncpy(mystr, *str, len));
71 	for (i = 0; i < l; i++)
72 		mystr[i] = (char) tolower((unsigned char)mystr[i]);
73 	for (i = 0; arr[i] && strcmp(mystr, arr[i]) != 0; i++);
74 	if (arr[i] == NULL)
75 		i = -1;
76 	else {			/* Skip past it */
77 		while (**str && isalpha((unsigned char)**str))
78 			++(*str);
79 		/* And any following whitespace */
80 		while (**str && (**str == ',' || isspace((unsigned char)**str)))
81 			++(*str);
82 	}			/* Return index */
83 	return i;
84 }
85 
86 static int
87 weekday(char const ** str)
88 {
89 	static char const *days[] =
90 	{"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL};
91 
92 	return aindex(days, str, 3);
93 }
94 
95 static int
96 month(char const ** str)
97 {
98 	static char const *months[] =
99 	{"jan", "feb", "mar", "apr", "may", "jun", "jul",
100 	"aug", "sep", "oct", "nov", "dec", NULL};
101 
102 	return aindex(months, str, 3);
103 }
104 
105 static void
106 parse_time(char const * str, int *hour, int *min, int *sec)
107 {
108 	*hour = a2i(&str);
109 	if ((str = strchr(str, ':')) == NULL)
110 		*min = *sec = 0;
111 	else {
112 		++str;
113 		*min = a2i(&str);
114 		*sec = ((str = strchr(str, ':')) == NULL) ? 0 : atoi(++str);
115 	}
116 }
117 
118 
119 static void
120 parse_datesub(char const * str, int *day, int *mon, int *year)
121 {
122 	int             i;
123 
124 	static char const nchrs[] = "0123456789 \t,/-.";
125 
126 	if ((i = month(&str)) != -1) {
127 		*mon = i;
128 		if ((i = a2i(&str)) != 0)
129 			*day = i;
130 	} else if ((i = a2i(&str)) != 0) {
131 		*day = i;
132 		while (*str && strchr(nchrs + 10, *str) != NULL)
133 			++str;
134 		if ((i = month(&str)) != -1)
135 			*mon = i;
136 		else if ((i = a2i(&str)) != 0)
137 			*mon = i - 1;
138 	} else
139 		return;
140 
141 	while (*str && strchr(nchrs + 10, *str) != NULL)
142 		++str;
143 	if (isdigit((unsigned char)*str)) {
144 		*year = atoi(str);
145 		if (*year > 1900)
146 			*year -= 1900;
147 		else if (*year < 32)
148 			*year += 100;
149 	}
150 }
151 
152 
153 /*-
154  * Parse time must be flexible, it handles the following formats:
155  * nnnnnnnnnnn		UNIX timestamp (all numeric), 0 = now
156  * 0xnnnnnnnn		UNIX timestamp in hexadecimal
157  * 0nnnnnnnnn		UNIX timestamp in octal
158  * 0			Given time
159  * +nnnn[smhdwoy]	Given time + nnnn hours, mins, days, weeks, months or years
160  * -nnnn[smhdwoy]	Given time - nnnn hours, mins, days, weeks, months or years
161  * dd[ ./-]mmm[ ./-]yy	Date }
162  * hh:mm:ss		Time } May be combined
163  */
164 
165 time_t
166 parse_date(time_t dt, char const * str)
167 {
168 	char           *p;
169 	int             i;
170 	long            val;
171 	struct tm      *T;
172 
173 	if (dt == 0)
174 		dt = time(NULL);
175 
176 	while (*str && isspace((unsigned char)*str))
177 		++str;
178 
179 	if (numerics(str)) {
180 		dt = strtol(str, &p, 0);
181 	} else if (*str == '+' || *str == '-') {
182 		val = strtol(str, &p, 0);
183 		switch (*p) {
184 		case 'h':
185 		case 'H':	/* hours */
186 			dt += (val * 3600L);
187 			break;
188 		case '\0':
189 		case 'm':
190 		case 'M':	/* minutes */
191 			dt += (val * 60L);
192 			break;
193 		case 's':
194 		case 'S':	/* seconds */
195 			dt += val;
196 			break;
197 		case 'd':
198 		case 'D':	/* days */
199 			dt += (val * 86400L);
200 			break;
201 		case 'w':
202 		case 'W':	/* weeks */
203 			dt += (val * 604800L);
204 			break;
205 		case 'o':
206 		case 'O':	/* months */
207 			T = localtime(&dt);
208 			T->tm_mon += (int) val;
209 			i = T->tm_mday;
210 			goto fixday;
211 		case 'y':
212 		case 'Y':	/* years */
213 			T = localtime(&dt);
214 			T->tm_year += (int) val;
215 			i = T->tm_mday;
216 	fixday:
217 			dt = mktime(T);
218 			T = localtime(&dt);
219 			if (T->tm_mday != i) {
220 				T->tm_mday = 1;
221 				dt = mktime(T);
222 				dt -= (time_t) 86400L;
223 			}
224 		default:	/* unknown */
225 			break;	/* leave untouched */
226 		}
227 	} else {
228 		char           *q, tmp[64];
229 
230 		/*
231 		 * Skip past any weekday prefix
232 		 */
233 		weekday(&str);
234 		strlcpy(tmp, str, sizeof(tmp));
235 		str = tmp;
236 		T = localtime(&dt);
237 
238 		/*
239 		 * See if we can break off any timezone
240 		 */
241 		while ((q = strrchr(tmp, ' ')) != NULL) {
242 			if (strchr("(+-", q[1]) != NULL)
243 				*q = '\0';
244 			else {
245 				int             j = 1;
246 
247 				while (q[j] && isupper((unsigned char)q[j]))
248 					++j;
249 				if (q[j] == '\0')
250 					*q = '\0';
251 				else
252 					break;
253 			}
254 		}
255 
256 		/*
257 		 * See if there is a time hh:mm[:ss]
258 		 */
259 		if ((p = strchr(tmp, ':')) == NULL) {
260 
261 			/*
262 			 * No time string involved
263 			 */
264 			T->tm_hour = T->tm_min = T->tm_sec = 0;
265 			parse_datesub(tmp, &T->tm_mday, &T->tm_mon, &T->tm_year);
266 		} else {
267 			char            datestr[64], timestr[64];
268 
269 			/*
270 			 * Let's chip off the time string
271 			 */
272 			if ((q = strpbrk(p, " \t")) != NULL) {	/* Time first? */
273 				int             l = q - str;
274 
275 				strlcpy(timestr, str, l + 1);
276 				strlcpy(datestr, q + 1, sizeof(datestr));
277 				parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
278 				parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
279 			} else if ((q = strrchr(tmp, ' ')) != NULL) {	/* Time last */
280 				int             l = q - tmp;
281 
282 				strlcpy(timestr, q + 1, sizeof(timestr));
283 				strlcpy(datestr, tmp, l + 1);
284 			} else	/* Bail out */
285 				return dt;
286 			parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
287 			parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
288 		}
289 		dt = mktime(T);
290 	}
291 	return dt;
292 }
293