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
10USE_DATE(NEWTOY(date, "d:s:r:u[!dr]", TOYFLAG_BIN))
11
12config DATE
13  bool "date"
14  default y
15  help
16    usage: date [-u] [-r FILE] [-d DATE] [+DISPLAY_FORMAT] [-s 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
23    -d	Show DATE instead of current time (convert date format)
24    -r	Use modification time of FILE instead of current date
25    -s	+FORMAT for SET or -d (instead of MMDDhhmm[[CC]YY][.ss])
26    -u	Use UTC instead of current timezone
27
28    +FORMAT specifies display format string using these escapes:
29
30    %% literal %             %n newline              %t tab
31    %S seconds (00-60)       %M minute (00-59)       %m month (01-12)
32    %H hour (0-23)           %I hour (01-12)         %p AM/PM
33    %y short year (00-99)    %Y year                 %C century
34    %a short weekday name    %A weekday name         %u day of week (1-7, 1=mon)
35    %b short month name      %B month name           %Z timezone name
36    %j day of year (001-366) %d day of month (01-31) %e day of month ( 1-31)
37
38    %U Week of year (0-53 start sunday)   %W Week of year (0-53 start monday)
39    %V Week of year (1-53 start monday, week < 4 days not part of this year)
40
41    %D = "%m/%d/%y"    %r = "%I : %M : %S %p"   %T = "%H:%M:%S"   %h = "%b"
42    %x locale date     %X locale time           %c locale date/time
43*/
44
45#define FOR_date
46#include "toys.h"
47
48GLOBALS(
49  char *file;
50  char *setfmt;
51  char *showdate;
52)
53
54// Handle default posix date format: mmddhhmm[[cc]yy]
55// returns 0 success, nonzero for error
56int parse_posixdate(char *str, struct tm *tm)
57{
58  int len;
59
60  len = 0;
61  sscanf(str, "%2u%2u%2u%2u%n", &tm->tm_mon, &tm->tm_mday, &tm->tm_hour,
62    &tm->tm_min, &len);
63  if (len != 8) return 1;
64  str += len;
65  tm->tm_mon--;
66
67  // If year specified, overwrite one we fetched earlier
68  if (*str && *str != '.') {
69    unsigned year, r1 = tm->tm_year % 100, r2 = (tm->tm_year + 50) % 100,
70      century = tm->tm_year - r1;
71
72    len = 0;
73    sscanf(str, "%u%n", &year, &len);
74    if (len == 4) year -= 1900;
75    else if (len != 2) return 1;
76    str += len;
77
78    // 2 digit years, next 50 years are "future", last 50 years are "past".
79    // A "future" date in past is a century ahead.
80    // A non-future date in the future is a century behind.
81    if ((r1 < r2) ? (r1 < year && year < r2) : (year < r1 || year > r2)) {
82      if (year < r1) year += 100;
83    } else if (year > r1) year -= 100;
84    tm->tm_year = year + century;
85  }
86  if (*str == '.') {
87    len = 0;
88    sscanf(str, ".%u%n", &tm->tm_sec, &len);
89    str += len;
90  }
91
92  return *str;
93}
94
95void date_main(void)
96{
97  char *setdate = *toys.optargs, *format_string = "%a %b %e %H:%M:%S %Z %Y",
98       *tz = 0;
99  struct tm tm;
100
101  // We can't just pass a timezone to mktime because posix.
102  if (toys.optflags & FLAG_u) {
103    if (CFG_TOYBOX_FREE) tz = getenv("TZ");
104    setenv("TZ", "UTC", 1);
105    tzset();
106  }
107
108  if (TT.showdate) {
109    setdate = TT.showdate;
110    if (TT.setfmt) {
111      char *s = strptime(TT.showdate, TT.setfmt+(*TT.setfmt=='+'), &tm);
112
113      if (!s || *s) goto bad_date;
114    } else if (parse_posixdate(TT.showdate, &tm)) goto bad_date;
115  } else {
116    time_t now;
117
118    if (TT.file) {
119      struct stat st;
120
121      xstat(TT.file, &st);
122      now = st.st_mtim.tv_sec;
123    } else now = time(0);
124
125    ((toys.optflags & FLAG_u) ? gmtime_r : localtime_r)(&now, &tm);
126  }
127
128  setdate = *toys.optargs;
129  // Fall through if no arguments
130  if (!setdate);
131  // Display the date?
132  else if (*setdate == '+') {
133    format_string = toys.optargs[0]+1;
134    setdate = toys.optargs[1];
135
136  // Set the date
137  } else if (setdate) {
138    struct timeval tv;
139
140    if (parse_posixdate(setdate, &tm)) goto bad_date;
141
142    if (toys.optflags & FLAG_u) {
143      char *tz = CFG_TOYBOX_FREE ? getenv("TZ") : 0;
144
145      // We can't just pass a timezone to mktime because posix.
146      setenv("TZ", "UTC", 1);
147      tzset();
148      tv.tv_sec = mktime(&tm);
149      if (CFG_TOYBOX_FREE) {
150        if (tz) setenv("TZ", tz, 1);
151        else unsetenv("TZ");
152        tzset();
153      }
154    } else tv.tv_sec = mktime(&tm);
155    if (tv.tv_sec == (time_t)-1) goto bad_date;
156
157    tv.tv_usec = 0;
158    if (settimeofday(&tv, NULL) < 0) perror_msg("cannot set date");
159  }
160
161  if (toys.optflags & FLAG_u) {
162    if (tz) setenv("TZ", tz, 1);
163    else unsetenv("TZ");
164    tzset();
165  }
166
167  if (!strftime(toybuf, sizeof(toybuf), format_string, &tm))
168    perror_exit("bad format '%s'", format_string);
169  puts(toybuf);
170
171  return;
172
173bad_date:
174  error_exit("bad date '%s'", setdate);
175}
176