1 /* date.c - set/get the date
2 *
3 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
4 *
5 * See http://opengroup.org/onlinepubs/9699919799/utilities/date.html
6 *
7 * Note: setting a 2 year date is 50 years back/forward from today,
8 * not posix's hardwired magic dates.
9
10 USE_DATE(NEWTOY(date, "d:D:r:u[!dr]", TOYFLAG_BIN))
11
12 config DATE
13 bool "date"
14 default y
15 help
16 usage: date [-u] [-r FILE] [-d DATE] [+DISPLAY_FORMAT] [-D SET_FORMAT] [SET]
17
18 Set/get the current date/time. With no SET shows the current date.
19
20 Default SET format is "MMDDhhmm[[CC]YY][.ss]", that's (2 digits each)
21 month, day, hour (0-23), and minute. Optionally century, year, and second.
22 Also accepts "@UNIXTIME[.FRACTION]" as seconds since midnight Jan 1 1970.
23
24 -d Show DATE instead of current time (convert date format)
25 -D +FORMAT for SET or -d (instead of MMDDhhmm[[CC]YY][.ss])
26 -r Use modification time of FILE instead of current date
27 -u Use UTC instead of current timezone
28
29 +FORMAT specifies display format string using strftime(3) syntax:
30
31 %% literal % %n newline %t tab
32 %S seconds (00-60) %M minute (00-59) %m month (01-12)
33 %H hour (0-23) %I hour (01-12) %p AM/PM
34 %y short year (00-99) %Y year %C century
35 %a short weekday name %A weekday name %u day of week (1-7, 1=mon)
36 %b short month name %B month name %Z timezone name
37 %j day of year (001-366) %d day of month (01-31) %e day of month ( 1-31)
38 %N nanosec (output only)
39
40 %U Week of year (0-53 start sunday) %W Week of year (0-53 start monday)
41 %V Week of year (1-53 start monday, week < 4 days not part of this year)
42
43 %D = "%m/%d/%y" %r = "%I : %M : %S %p" %T = "%H:%M:%S" %h = "%b"
44 %x locale date %X locale time %c locale date/time
45 */
46
47 #define FOR_date
48 #include "toys.h"
49
GLOBALS(char * file;char * setfmt;char * showdate;unsigned nano;)50 GLOBALS(
51 char *file;
52 char *setfmt;
53 char *showdate;
54
55 unsigned nano;
56 )
57
58 // Handle default posix date format (mmddhhmm[[cc]yy]) or @UNIX[.FRAC]
59 // returns 0 success, nonzero for error
60 static int parse_default(char *str, struct tm *tm)
61 {
62 int len = 0;
63
64 // Parse @UNIXTIME[.FRACTION]
65 if (*str == '@') {
66 long long ll;
67 time_t tt;
68
69 // Collect seconds and nanoseconds
70 // Note: struct tm hasn't got a fractional seconds field, thus strptime()
71 // doesn't support it, so store nanoseconds out of band (in globals).
72 // tt and ll are separate because we can't guarantee time_t is 64 bit (yet).
73 sscanf(str, "@%lld%n", &ll, &len);
74 if (str[len]=='.') {
75 str += len+1;
76 for (len = 0; len<9; len++) {
77 TT.nano *= 10;
78 if (isdigit(str[len])) TT.nano += str[len]-'0';
79 }
80 }
81 if (str[len]) return 1;
82 tt = ll;
83 gmtime_r(&tt, tm);
84
85 return 0;
86 }
87
88 // Posix format
89 sscanf(str, "%2u%2u%2u%2u%n", &tm->tm_mon, &tm->tm_mday, &tm->tm_hour,
90 &tm->tm_min, &len);
91 if (len != 8) return 1;
92 str += len;
93 tm->tm_mon--;
94
95 // If year specified, overwrite one we fetched earlier
96 if (*str && *str != '.') {
97 unsigned year;
98
99 len = 0;
100 sscanf(str, "%u%n", &year, &len);
101 if (len == 4) tm->tm_year = year - 1900;
102 else if (len != 2) return 1;
103 str += len;
104
105 // 2 digit years, next 50 years are "future", last 50 years are "past".
106 // A "future" date in past is a century ahead.
107 // A non-future date in the future is a century behind.
108 if (len == 2) {
109 unsigned r1 = tm->tm_year % 100, r2 = (tm->tm_year + 50) % 100,
110 century = tm->tm_year - r1;
111
112 if ((r1 < r2) ? (r1 < year && year < r2) : (year < r1 || year > r2)) {
113 if (year < r1) year += 100;
114 } else if (year > r1) year -= 100;
115 tm->tm_year = year + century;
116 }
117 }
118 if (*str == '.') {
119 len = 0;
120 sscanf(str, ".%u%n", &tm->tm_sec, &len);
121 str += len;
122 } else tm->tm_sec = 0;
123
124 return *str;
125 }
126
check_range(int a,int low,int high)127 static void check_range(int a, int low, int high)
128 {
129 if (a<low) error_exit("%d<%d", a, low);
130 if (a>high) error_exit("%d>%d", a, high);
131 }
132
133 // Print strftime plus %N escape(s). note: modifies fmt for %N
puts_time(char * fmt,struct tm * tm)134 static void puts_time(char *fmt, struct tm *tm)
135 {
136 char *s, *snap;
137 long width = width;
138
139 for (s = fmt;;s++) {
140
141 // Find next %N or end
142 if (*(snap = s) == '%') {
143 width = isdigit(*++s) ? *(s++)-'0' : 9;
144 if (*s && *s != 'N') continue;
145 } else if (*s) continue;
146
147 // Don't modify input string if no %N (default format is constant string).
148 if (*s) *snap = 0;
149 if (!strftime(toybuf, sizeof(toybuf)-10, fmt, tm))
150 perror_exit("bad format '%s'", fmt);
151 if (*s) {
152 snap = toybuf+strlen(toybuf);
153 sprintf(snap, "%09u", TT.nano);
154 snap[width] = 0;
155 }
156 fputs(toybuf, stdout);
157 if (!*s || !*(fmt = s+1)) break;
158 }
159 xputc('\n');
160 }
161
date_main(void)162 void date_main(void)
163 {
164 char *setdate = *toys.optargs, *format_string = "%a %b %e %H:%M:%S %Z %Y";
165 struct tm tm;
166
167 memset(&tm, 0, sizeof(struct tm));
168
169 if (TT.showdate) {
170 if (TT.setfmt) {
171 char *s = strptime(TT.showdate, TT.setfmt+(*TT.setfmt=='+'), &tm);
172
173 if (!s || *s) goto bad_showdate;
174 } else if (parse_default(TT.showdate, &tm)) goto bad_showdate;
175 } else {
176 struct timespec ts;
177 struct stat st;
178
179 if (TT.file) {
180 xstat(TT.file, &st);
181 ts = st.st_mtim;
182 } else clock_gettime(CLOCK_REALTIME, &ts);
183
184 ((toys.optflags & FLAG_u) ? gmtime_r : localtime_r)(&ts.tv_sec, &tm);
185 TT.nano = ts.tv_nsec;
186 }
187
188 // Fall through if no arguments
189 if (!setdate);
190 // Display the date?
191 else if (*setdate == '+') {
192 format_string = toys.optargs[0]+1;
193 setdate = toys.optargs[1];
194
195 // Set the date
196 } else if (setdate) {
197 char *tz;
198 struct timeval tv;
199 int u = toys.optflags & FLAG_u;
200
201 if (parse_default(setdate, &tm)) goto bad_setdate;
202
203 check_range(tm.tm_sec, 0, 60);
204 check_range(tm.tm_min, 0, 59);
205 check_range(tm.tm_hour, 0, 23);
206 check_range(tm.tm_mday, 1, 31);
207 check_range(tm.tm_mon, 0, 11);
208
209 if (u) {
210 tz = getenv("TZ");
211 setenv("TZ", "UTC", 1);
212 tzset();
213 }
214 errno = 0;
215 tv.tv_sec = mktime(&tm);
216 if (errno) goto bad_setdate;
217 if (u) {
218 if (tz) setenv("TZ", tz, 1);
219 else unsetenv("TZ");
220 tzset();
221 }
222
223 tv.tv_usec = TT.nano/1000;
224 if (settimeofday(&tv, NULL) < 0) perror_msg("cannot set date");
225 }
226
227 puts_time(format_string, &tm);
228 return;
229
230 bad_showdate:
231 setdate = TT.showdate;
232 bad_setdate:
233 perror_exit("bad date '%s'", setdate);
234 }
235