xref: /freebsd/usr.sbin/pw/psdate.c (revision ea906c4152774dff300bb26fbfc1e4188351c89a)
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 
27 #ifndef lint
28 static const char rcsid[] =
29   "$FreeBSD$";
30 #endif /* not lint */
31 
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <ctype.h>
36 
37 #include "psdate.h"
38 
39 
40 static int
41 a2i(char const ** str)
42 {
43 	int             i = 0;
44 	char const     *s = *str;
45 
46 	if (isdigit((unsigned char)*s)) {
47 		i = atoi(s);
48 		while (isdigit((unsigned char)*s))
49 			++s;
50 		*str = s;
51 	}
52 	return i;
53 }
54 
55 static int
56 numerics(char const * str)
57 {
58 	int             rc = isdigit((unsigned char)*str);
59 
60 	if (rc)
61 		while (isdigit((unsigned char)*str) || *str == 'x')
62 			++str;
63 	return rc && !*str;
64 }
65 
66 static int
67 aindex(char const * arr[], char const ** str, int len)
68 {
69 	int             l, i;
70 	char            mystr[32];
71 
72 	mystr[len] = '\0';
73 	l = strlen(strncpy(mystr, *str, len));
74 	for (i = 0; i < l; i++)
75 		mystr[i] = (char) tolower((unsigned char)mystr[i]);
76 	for (i = 0; arr[i] && strcmp(mystr, arr[i]) != 0; i++);
77 	if (arr[i] == NULL)
78 		i = -1;
79 	else {			/* Skip past it */
80 		while (**str && isalpha((unsigned char)**str))
81 			++(*str);
82 		/* And any following whitespace */
83 		while (**str && (**str == ',' || isspace((unsigned char)**str)))
84 			++(*str);
85 	}			/* Return index */
86 	return i;
87 }
88 
89 static int
90 weekday(char const ** str)
91 {
92 	static char const *days[] =
93 	{"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL};
94 
95 	return aindex(days, str, 3);
96 }
97 
98 static int
99 month(char const ** str)
100 {
101 	static char const *months[] =
102 	{"jan", "feb", "mar", "apr", "may", "jun", "jul",
103 	"aug", "sep", "oct", "nov", "dec", NULL};
104 
105 	return aindex(months, str, 3);
106 }
107 
108 static void
109 parse_time(char const * str, int *hour, int *min, int *sec)
110 {
111 	*hour = a2i(&str);
112 	if ((str = strchr(str, ':')) == NULL)
113 		*min = *sec = 0;
114 	else {
115 		++str;
116 		*min = a2i(&str);
117 		*sec = ((str = strchr(str, ':')) == NULL) ? 0 : atoi(++str);
118 	}
119 }
120 
121 
122 static void
123 parse_datesub(char const * str, int *day, int *mon, int *year)
124 {
125 	int             i;
126 
127 	static char const nchrs[] = "0123456789 \t,/-.";
128 
129 	if ((i = month(&str)) != -1) {
130 		*mon = i;
131 		if ((i = a2i(&str)) != 0)
132 			*day = i;
133 	} else if ((i = a2i(&str)) != 0) {
134 		*day = i;
135 		while (*str && strchr(nchrs + 10, *str) != NULL)
136 			++str;
137 		if ((i = month(&str)) != -1)
138 			*mon = i;
139 		else if ((i = a2i(&str)) != 0)
140 			*mon = i - 1;
141 	} else
142 		return;
143 
144 	while (*str && strchr(nchrs + 10, *str) != NULL)
145 		++str;
146 	if (isdigit((unsigned char)*str)) {
147 		*year = atoi(str);
148 		if (*year > 1900)
149 			*year -= 1900;
150 		else if (*year < 32)
151 			*year += 100;
152 	}
153 }
154 
155 
156 /*-
157  * Parse time must be flexible, it handles the following formats:
158  * nnnnnnnnnnn		UNIX timestamp (all numeric), 0 = now
159  * 0xnnnnnnnn		UNIX timestamp in hexadecimal
160  * 0nnnnnnnnn		UNIX timestamp in octal
161  * 0			Given time
162  * +nnnn[smhdwoy]	Given time + nnnn hours, mins, days, weeks, months or years
163  * -nnnn[smhdwoy]	Given time - nnnn hours, mins, days, weeks, months or years
164  * dd[ ./-]mmm[ ./-]yy	Date }
165  * hh:mm:ss		Time } May be combined
166  */
167 
168 time_t
169 parse_date(time_t dt, char const * str)
170 {
171 	char           *p;
172 	int             i;
173 	long            val;
174 	struct tm      *T;
175 
176 	if (dt == 0)
177 		dt = time(NULL);
178 
179 	while (*str && isspace((unsigned char)*str))
180 		++str;
181 
182 	if (numerics(str)) {
183 		dt = strtol(str, &p, 0);
184 	} else if (*str == '+' || *str == '-') {
185 		val = strtol(str, &p, 0);
186 		switch (*p) {
187 		case 'h':
188 		case 'H':	/* hours */
189 			dt += (val * 3600L);
190 			break;
191 		case '\0':
192 		case 'm':
193 		case 'M':	/* minutes */
194 			dt += (val * 60L);
195 			break;
196 		case 's':
197 		case 'S':	/* seconds */
198 			dt += val;
199 			break;
200 		case 'd':
201 		case 'D':	/* days */
202 			dt += (val * 86400L);
203 			break;
204 		case 'w':
205 		case 'W':	/* weeks */
206 			dt += (val * 604800L);
207 			break;
208 		case 'o':
209 		case 'O':	/* months */
210 			T = localtime(&dt);
211 			T->tm_mon += (int) val;
212 			i = T->tm_mday;
213 			goto fixday;
214 		case 'y':
215 		case 'Y':	/* years */
216 			T = localtime(&dt);
217 			T->tm_year += (int) val;
218 			i = T->tm_mday;
219 	fixday:
220 			dt = mktime(T);
221 			T = localtime(&dt);
222 			if (T->tm_mday != i) {
223 				T->tm_mday = 1;
224 				dt = mktime(T);
225 				dt -= (time_t) 86400L;
226 			}
227 		default:	/* unknown */
228 			break;	/* leave untouched */
229 		}
230 	} else {
231 		char           *q, tmp[64];
232 
233 		/*
234 		 * Skip past any weekday prefix
235 		 */
236 		weekday(&str);
237 		strlcpy(tmp, str, sizeof(tmp));
238 		str = tmp;
239 		T = localtime(&dt);
240 
241 		/*
242 		 * See if we can break off any timezone
243 		 */
244 		while ((q = strrchr(tmp, ' ')) != NULL) {
245 			if (strchr("(+-", q[1]) != NULL)
246 				*q = '\0';
247 			else {
248 				int             j = 1;
249 
250 				while (q[j] && isupper((unsigned char)q[j]))
251 					++j;
252 				if (q[j] == '\0')
253 					*q = '\0';
254 				else
255 					break;
256 			}
257 		}
258 
259 		/*
260 		 * See if there is a time hh:mm[:ss]
261 		 */
262 		if ((p = strchr(tmp, ':')) == NULL) {
263 
264 			/*
265 			 * No time string involved
266 			 */
267 			T->tm_hour = T->tm_min = T->tm_sec = 0;
268 			parse_datesub(tmp, &T->tm_mday, &T->tm_mon, &T->tm_year);
269 		} else {
270 			char            datestr[64], timestr[64];
271 
272 			/*
273 			 * Let's chip off the time string
274 			 */
275 			if ((q = strpbrk(p, " \t")) != NULL) {	/* Time first? */
276 				int             l = q - str;
277 
278 				strlcpy(timestr, str, l + 1);
279 				strlcpy(datestr, q + 1, sizeof(datestr));
280 				parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
281 				parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
282 			} else if ((q = strrchr(tmp, ' ')) != NULL) {	/* Time last */
283 				int             l = q - tmp;
284 
285 				strlcpy(timestr, q + 1, sizeof(timestr));
286 				strlcpy(datestr, tmp, l + 1);
287 			} else	/* Bail out */
288 				return dt;
289 			parse_time(timestr, &T->tm_hour, &T->tm_min, &T->tm_sec);
290 			parse_datesub(datestr, &T->tm_mday, &T->tm_mon, &T->tm_year);
291 		}
292 		dt = mktime(T);
293 	}
294 	return dt;
295 }
296