tweak comment, no code changes
[platform/upstream/busybox.git] / libbb / time.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Utility routines.
4  *
5  * Copyright (C) 2007 Denys Vlasenko
6  *
7  * Licensed under GPLv2, see file LICENSE in this source tree.
8  */
9 #include "libbb.h"
10
11 void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
12 {
13         char end = '\0';
14         const char *last_colon = strrchr(date_str, ':');
15
16         if (last_colon != NULL) {
17                 /* Parse input and assign appropriately to ptm */
18 #if ENABLE_DESKTOP
19                 const char *endp;
20 #endif
21
22                 /* HH:MM */
23                 if (sscanf(date_str, "%u:%u%c",
24                                         &ptm->tm_hour,
25                                         &ptm->tm_min,
26                                         &end) >= 2) {
27                         /* no adjustments needed */
28                 } else
29                 /* mm.dd-HH:MM */
30                 if (sscanf(date_str, "%u.%u-%u:%u%c",
31                                         &ptm->tm_mon, &ptm->tm_mday,
32                                         &ptm->tm_hour, &ptm->tm_min,
33                                         &end) >= 4) {
34                         /* Adjust month from 1-12 to 0-11 */
35                         ptm->tm_mon -= 1;
36                 } else
37                 /* yyyy.mm.dd-HH:MM */
38                 if (sscanf(date_str, "%u.%u.%u-%u:%u%c", &ptm->tm_year,
39                                         &ptm->tm_mon, &ptm->tm_mday,
40                                         &ptm->tm_hour, &ptm->tm_min,
41                                         &end) >= 5) {
42                         ptm->tm_year -= 1900; /* Adjust years */
43                         ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
44                 } else
45                 /* yyyy-mm-dd HH:MM */
46                 if (sscanf(date_str, "%u-%u-%u %u:%u%c", &ptm->tm_year,
47                                         &ptm->tm_mon, &ptm->tm_mday,
48                                         &ptm->tm_hour, &ptm->tm_min,
49                                         &end) >= 5) {
50                         ptm->tm_year -= 1900; /* Adjust years */
51                         ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
52                 } else
53 #if ENABLE_DESKTOP  /* strptime is BIG: ~1k in uclibc, ~10k in glibc */
54                 /* month_name d HH:MM:SS YYYY. Supported by GNU date */
55                 if ((endp = strptime(date_str, "%b %d %T %Y", ptm)) != NULL
56                  && *endp == '\0'
57                 ) {
58                         return; /* don't fall through to end == ":" check */
59                 } else
60 #endif
61 //TODO: coreutils 6.9 also accepts "yyyy-mm-dd HH" (no minutes)
62                 {
63                         bb_error_msg_and_die(bb_msg_invalid_date, date_str);
64                 }
65                 if (end == ':') {
66                         /* xxx:SS */
67                         if (sscanf(last_colon + 1, "%u%c", &ptm->tm_sec, &end) == 1)
68                                 end = '\0';
69                         /* else end != NUL and we error out */
70                 }
71         } else if (date_str[0] == '@') {
72                 time_t t = bb_strtol(date_str + 1, NULL, 10);
73                 if (!errno) {
74                         struct tm *lt = localtime(&t);
75                         if (lt) {
76                                 *ptm = *lt;
77                                 return;
78                         }
79                 }
80                 end = '1';
81         } else {
82                 /* Googled the following on an old date manpage:
83                  *
84                  * The canonical representation for setting the date/time is:
85                  * cc   Century (either 19 or 20)
86                  * yy   Year in abbreviated form (e.g. 89, 06)
87                  * mm   Numeric month, a number from 1 to 12
88                  * dd   Day, a number from 1 to 31
89                  * HH   Hour, a number from 0 to 23
90                  * MM   Minutes, a number from 0 to 59
91                  * .SS  Seconds, a number from 0 to 61 (with leap seconds)
92                  * Everything but the minutes is optional
93                  *
94                  * "touch -t DATETIME" format: [[[[[YY]YY]MM]DD]hh]mm[.ss]
95                  * Some, but not all, Unix "date DATETIME" commands
96                  * move [[YY]YY] past minutes mm field (!).
97                  * Coreutils date does it, and SUS mandates it.
98                  * (date -s DATETIME does not support this format. lovely!)
99                  * In bbox, this format is special-cased in date applet
100                  * (IOW: this function assumes "touch -t" format).
101                  */
102                 unsigned cur_year = ptm->tm_year;
103                 int len = strchrnul(date_str, '.') - date_str;
104
105                 /* MM[.SS] */
106                 if (len == 2 && sscanf(date_str, "%2u%2u%2u%2u""%2u%c" + 12,
107                                         &ptm->tm_min,
108                                         &end) >= 1) {
109                 } else
110                 /* HHMM[.SS] */
111                 if (len == 4 && sscanf(date_str, "%2u%2u%2u""%2u%2u%c" + 9,
112                                         &ptm->tm_hour,
113                                         &ptm->tm_min,
114                                         &end) >= 2) {
115                 } else
116                 /* ddHHMM[.SS] */
117                 if (len == 6 && sscanf(date_str, "%2u%2u""%2u%2u%2u%c" + 6,
118                                         &ptm->tm_mday,
119                                         &ptm->tm_hour,
120                                         &ptm->tm_min,
121                                         &end) >= 3) {
122                 } else
123                 /* mmddHHMM[.SS] */
124                 if (len == 8 && sscanf(date_str, "%2u""%2u%2u%2u%2u%c" + 3,
125                                         &ptm->tm_mon,
126                                         &ptm->tm_mday,
127                                         &ptm->tm_hour,
128                                         &ptm->tm_min,
129                                         &end) >= 4) {
130                         /* Adjust month from 1-12 to 0-11 */
131                         ptm->tm_mon -= 1;
132                 } else
133                 /* yymmddHHMM[.SS] */
134                 if (len == 10 && sscanf(date_str, "%2u%2u%2u%2u%2u%c",
135                                         &ptm->tm_year,
136                                         &ptm->tm_mon,
137                                         &ptm->tm_mday,
138                                         &ptm->tm_hour,
139                                         &ptm->tm_min,
140                                         &end) >= 5) {
141                         /* Adjust month from 1-12 to 0-11 */
142                         ptm->tm_mon -= 1;
143                         if ((int)cur_year >= 50) { /* >= 1950 */
144                                 /* Adjust year: */
145                                 /* 1. Put it in the current century */
146                                 ptm->tm_year += (cur_year / 100) * 100;
147                                 /* 2. If too far in the past, +100 years */
148                                 if (ptm->tm_year < cur_year - 50)
149                                         ptm->tm_year += 100;
150                                 /* 3. If too far in the future, -100 years */
151                                 if (ptm->tm_year > cur_year + 50)
152                                         ptm->tm_year -= 100;
153                         }
154                 } else
155                 /* ccyymmddHHMM[.SS] */
156                 if (len == 12 && sscanf(date_str, "%4u%2u%2u%2u%2u%c",
157                                         &ptm->tm_year,
158                                         &ptm->tm_mon,
159                                         &ptm->tm_mday,
160                                         &ptm->tm_hour,
161                                         &ptm->tm_min,
162                                         &end) >= 5) {
163                         ptm->tm_year -= 1900; /* Adjust years */
164                         ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
165                 } else {
166                         bb_error_msg_and_die(bb_msg_invalid_date, date_str);
167                 }
168                 if (end == '.') {
169                         /* xxx.SS */
170                         if (sscanf(strchr(date_str, '.') + 1, "%u%c",
171                                         &ptm->tm_sec, &end) == 1)
172                                 end = '\0';
173                         /* else end != NUL and we error out */
174                 }
175         }
176         if (end != '\0') {
177                 bb_error_msg_and_die(bb_msg_invalid_date, date_str);
178         }
179 }
180
181 time_t FAST_FUNC validate_tm_time(const char *date_str, struct tm *ptm)
182 {
183         time_t t = mktime(ptm);
184         if (t == (time_t) -1L) {
185                 bb_error_msg_and_die(bb_msg_invalid_date, date_str);
186         }
187         return t;
188 }
189
190 #if ENABLE_MONOTONIC_SYSCALL
191
192 #include <sys/syscall.h>
193 /* Old glibc (< 2.3.4) does not provide this constant. We use syscall
194  * directly so this definition is safe. */
195 #ifndef CLOCK_MONOTONIC
196 #define CLOCK_MONOTONIC 1
197 #endif
198
199 /* libc has incredibly messy way of doing this,
200  * typically requiring -lrt. We just skip all this mess */
201 static void get_mono(struct timespec *ts)
202 {
203         if (syscall(__NR_clock_gettime, CLOCK_MONOTONIC, ts))
204                 bb_error_msg_and_die("clock_gettime(MONOTONIC) failed");
205 }
206 unsigned long long FAST_FUNC monotonic_ns(void)
207 {
208         struct timespec ts;
209         get_mono(&ts);
210         return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
211 }
212 unsigned long long FAST_FUNC monotonic_us(void)
213 {
214         struct timespec ts;
215         get_mono(&ts);
216         return ts.tv_sec * 1000000ULL + ts.tv_nsec/1000;
217 }
218 unsigned long long FAST_FUNC monotonic_ms(void)
219 {
220         struct timespec ts;
221         get_mono(&ts);
222         return ts.tv_sec * 1000ULL + ts.tv_nsec/1000000;
223 }
224 unsigned FAST_FUNC monotonic_sec(void)
225 {
226         struct timespec ts;
227         get_mono(&ts);
228         return ts.tv_sec;
229 }
230
231 #else
232
233 unsigned long long FAST_FUNC monotonic_ns(void)
234 {
235         struct timeval tv;
236         gettimeofday(&tv, NULL);
237         return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
238 }
239 unsigned long long FAST_FUNC monotonic_us(void)
240 {
241         struct timeval tv;
242         gettimeofday(&tv, NULL);
243         return tv.tv_sec * 1000000ULL + tv.tv_usec;
244 }
245 unsigned long long FAST_FUNC monotonic_ms(void)
246 {
247         struct timeval tv;
248         gettimeofday(&tv, NULL);
249         return tv.tv_sec * 1000ULL + tv.tv_usec / 1000;
250 }
251 unsigned FAST_FUNC monotonic_sec(void)
252 {
253         return time(NULL);
254 }
255
256 #endif