summaryrefslogtreecommitdiff
path: root/coreutils/date.c
blob: 2aecbaac25a10540b245f743d987a4230782b2e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/* vi: set sw=4 ts=4: */
/*
 * Mini date implementation for busybox
 *
 * by Matthew Grant <grantma@anathoth.gen.nz>
 *
 * iso-format handling added by Robert Griebl <griebl@gmx.de>
 * bugfixes and cleanup by Bernhard Fischer
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/

#include "libbb.h"

/* This 'date' command supports only 2 time setting formats,
   all the GNU strftime stuff (its in libc, lets use it),
   setting time using UTC and displaying it, as well as
   an RFC 2822 compliant date output for shell scripting
   mail commands */

/* Input parsing code is always bulky - used heavy duty libc stuff as
   much as possible, missed out a lot of bounds checking */

/* Default input handling to save surprising some people */


#define DATE_OPT_RFC2822	0x01
#define DATE_OPT_SET		0x02
#define DATE_OPT_UTC		0x04
#define DATE_OPT_DATE		0x08
#define DATE_OPT_REFERENCE	0x10
#define DATE_OPT_TIMESPEC	0x20
#define DATE_OPT_HINT		0x40

static void maybe_set_utc(int opt)
{
	if (opt & DATE_OPT_UTC)
		putenv((char*)"TZ=UTC0");
}

int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int date_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
	struct tm tm_time;
	time_t tm;
	unsigned opt;
	int ifmt = -1;
	char *date_str;
	char *fmt_dt2str;
	char *fmt_str2dt;
	char *filename;
	char *isofmt_arg = NULL;

	opt_complementary = "d--s:s--d"
		USE_FEATURE_DATE_ISOFMT(":R--I:I--R");
	opt = getopt32(argv, "Rs:ud:r:"
			USE_FEATURE_DATE_ISOFMT("I::D:"),
			&date_str, &date_str, &filename
			USE_FEATURE_DATE_ISOFMT(, &isofmt_arg, &fmt_str2dt));
	argv += optind;
	maybe_set_utc(opt);

	if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_TIMESPEC)) {
		ifmt = 0; /* default is date */
		if (isofmt_arg) {
			static const char isoformats[] ALIGN1 =
				"date\0""hours\0""minutes\0""seconds\0";
			ifmt = index_in_strings(isoformats, isofmt_arg);
			if (ifmt < 0)
				bb_show_usage();
		}
	}

	fmt_dt2str = NULL;
	if (argv[0] && argv[0][0] == '+') {
		fmt_dt2str = &argv[0][1];	/* Skip over the '+' */
		argv++;
	}
	if (!(opt & (DATE_OPT_SET | DATE_OPT_DATE))) {
		opt |= DATE_OPT_SET;
		date_str = argv[0]; /* can be NULL */
	}

	/* Now we have parsed all the information except the date format
	   which depends on whether the clock is being set or read */

	if (opt & DATE_OPT_REFERENCE) {
		struct stat statbuf;
		xstat(filename, &statbuf);
		tm = statbuf.st_mtime;
	} else
		time(&tm);
	memcpy(&tm_time, localtime(&tm), sizeof(tm_time));

	/* If date string is given, update tm_time, and maybe set date */
	if (date_str != NULL) {
		/* Zero out fields - take her back to midnight! */
		tm_time.tm_sec = 0;
		tm_time.tm_min = 0;
		tm_time.tm_hour = 0;

		/* Process any date input to UNIX time since 1 Jan 1970 */
		if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_HINT)) {
			if (strptime(date_str, fmt_str2dt, &tm_time) == NULL)
				bb_error_msg_and_die(bb_msg_invalid_date, date_str);
		} else {
			char end = '\0';
			const char *last_colon = strrchr(date_str, ':');

			if (last_colon != NULL) {
				/* Parse input and assign appropriately to tm_time */

				if (sscanf(date_str, "%u:%u%c",
								&tm_time.tm_hour,
								&tm_time.tm_min,
								&end) >= 2) {
					/* no adjustments needed */
				} else if (sscanf(date_str, "%u.%u-%u:%u%c",
								&tm_time.tm_mon, &tm_time.tm_mday,
								&tm_time.tm_hour, &tm_time.tm_min,
								&end) >= 4) {
					/* Adjust dates from 1-12 to 0-11 */
					tm_time.tm_mon -= 1;
				} else if (sscanf(date_str, "%u.%u.%u-%u:%u%c", &tm_time.tm_year,
								&tm_time.tm_mon, &tm_time.tm_mday,
								&tm_time.tm_hour, &tm_time.tm_min,
								&end) >= 5) {
					tm_time.tm_year -= 1900; /* Adjust years */
					tm_time.tm_mon -= 1; /* Adjust dates from 1-12 to 0-11 */
				} else if (sscanf(date_str, "%u-%u-%u %u:%u%c", &tm_time.tm_year,
								&tm_time.tm_mon, &tm_time.tm_mday,
								&tm_time.tm_hour, &tm_time.tm_min,
								&end) >= 5) {
					tm_time.tm_year -= 1900; /* Adjust years */
					tm_time.tm_mon -= 1; /* Adjust dates from 1-12 to 0-11 */
//TODO: coreutils 6.9 also accepts "YYYY-MM-DD HH" (no minutes)
				} else {
					bb_error_msg_and_die(bb_msg_invalid_date, date_str);
				}
				if (end == ':') {
					if (sscanf(last_colon + 1, "%u%c", &tm_time.tm_sec, &end) == 1)
						end = '\0';
					/* else end != NUL and we error out */
				}
			} else {
				if (sscanf(date_str, "%2u%2u%2u%2u%u%c", &tm_time.tm_mon,
							&tm_time.tm_mday, &tm_time.tm_hour, &tm_time.tm_min,
							&tm_time.tm_year, &end) < 4)
					bb_error_msg_and_die(bb_msg_invalid_date, date_str);
				/* correct for century  - minor Y2K problem here? */
				if (tm_time.tm_year >= 1900) {
					tm_time.tm_year -= 1900;
				}
				/* adjust date */
				tm_time.tm_mon -= 1;
				if (end == '.') {
					if (sscanf(strchr(date_str, '.') + 1, "%u%c",
							&tm_time.tm_sec, &end) == 1)
						end = '\0';
					/* else end != NUL and we error out */
				}
			}
			if (end != '\0') {
				bb_error_msg_and_die(bb_msg_invalid_date, date_str);
			}
		}
		/* Correct any day of week and day of year etc. fields */
		tm_time.tm_isdst = -1;	/* Be sure to recheck dst. */
		tm = mktime(&tm_time);
		if (tm < 0) {
			bb_error_msg_and_die(bb_msg_invalid_date, date_str);
		}
		maybe_set_utc(opt);

		/* if setting time, set it */
		if ((opt & DATE_OPT_SET) && stime(&tm) < 0) {
			bb_perror_msg("cannot set date");
		}
	}

	/* Display output */

	/* Deal with format string */
	if (fmt_dt2str == NULL) {
		int i;
		fmt_dt2str = xzalloc(32);
		if (ENABLE_FEATURE_DATE_ISOFMT && ifmt >= 0) {
			strcpy(fmt_dt2str, "%Y-%m-%d");
			if (ifmt > 0) {
				i = 8;
				fmt_dt2str[i++] = 'T';
				fmt_dt2str[i++] = '%';
				fmt_dt2str[i++] = 'H';
				if (ifmt > 1) {
					fmt_dt2str[i++] = ':';
					fmt_dt2str[i++] = '%';
					fmt_dt2str[i++] = 'M';
					if (ifmt > 2) {
						fmt_dt2str[i++] = ':';
						fmt_dt2str[i++] = '%';
						fmt_dt2str[i++] = 'S';
					}
				}
 format_utc:
				fmt_dt2str[i++] = '%';
				fmt_dt2str[i] = (opt & DATE_OPT_UTC) ? 'Z' : 'z';
			}
		} else if (opt & DATE_OPT_RFC2822) {
			/* Undo busybox.c for date -R */
			if (ENABLE_LOCALE_SUPPORT)
				setlocale(LC_TIME, "C");
			strcpy(fmt_dt2str, "%a, %d %b %Y %H:%M:%S ");
			i = 22;
			goto format_utc;
		} else /* default case */
			fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
	}

#define date_buf bb_common_bufsiz1
	if (*fmt_dt2str == '\0') {
		/* With no format string, just print a blank line */
		date_buf[0] = '\0';
	} else {
		/* Handle special conversions */
		if (strncmp(fmt_dt2str, "%f", 2) == 0) {
			fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
		}

		/* Generate output string */
		strftime(date_buf, sizeof(date_buf), fmt_dt2str, &tm_time);
	}
	puts(date_buf);

	return EXIT_SUCCESS;
}