date.c revision c0e56edaf256adb6c60c5a052525a1ffbb927901 
1/* vi: set sw=4 ts=4:
2 *
3 * date.c - set/get the date
4 *
5 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
6 *
7 * See http://opengroup.org/onlinepubs/9699919799/utilities/date.html
8
9USE_DATE(NEWTOY(date, "r:u", TOYFLAG_BIN))
10
11config DATE
12	bool "date"
13	default y
14	help
15	  usage: date [-u] [-r file] [+format] | mmddhhmm[[cc]yy]
16
17	  Set/get the current date/time
18*/
19
20#define FOR_date
21#include "toys.h"
22
23GLOBALS(
24    char *file;
25)
26
27void date_main(void)
28{
29    const char *format_string = "%a %b %e %H:%M:%S %Z %Y";
30    time_t now = time(NULL);
31    struct tm tm;
32
33    if (TT.file) {
34        struct stat st;
35
36        xstat(TT.file, &st);
37        now = st.st_mtim.tv_sec;
38    }
39    ((toys.optflags & FLAG_u) ? gmtime_r : localtime_r)(&now, &tm);
40
41    // Display the date?
42    if (!toys.optargs[0] || toys.optargs[0][0] == '+') {
43        if (toys.optargs[0]) format_string = toys.optargs[0]+1;
44        if (!strftime(toybuf, sizeof(toybuf), format_string, &tm))
45            perror_msg("bad format `%s'", format_string);
46
47        puts(toybuf);
48
49    // Set the date
50    } else {
51        struct timeval tv;
52        char *s = *toys.optargs;
53        int len = strlen(s);
54
55        if (len < 8 || len > 12 || (len & 1)) error_msg("bad date `%s'", s);
56
57        // Date format: mmddhhmm[[cc]yy]
58        memset(&tm, 0, sizeof(tm));
59        len = sscanf(s, "%2u%2u%2u%2u", &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
60               &tm.tm_min);
61        tm.tm_mon--;
62
63        // If year specified, overwrite one we fetched earlier
64        if (len > 8) {
65            sscanf(s, "%u", &tm.tm_year);
66            if (len == 12) tm.tm_year -= 1900;
67            /* 69-99 = 1969-1999, 0 - 68 = 2000-2068 */
68            else if (tm.tm_year < 69) tm.tm_year += 100;
69        }
70
71        if (toys.optflags & FLAG_u) {
72            // Get the UTC version of a struct tm
73            char *tz = CFG_TOYBOX_FREE ? getenv("TZ") : 0;
74            setenv("TZ", "UTC", 1);
75            tzset();
76            tv.tv_sec = mktime(&tm);
77            if (CFG_TOYBOX_FREE) {
78                if (tz) setenv("TZ", tz, 1);
79                else unsetenv("TZ");
80                tzset();
81            }
82        } else tv.tv_sec = mktime(&tm);
83
84        if (tv.tv_sec == (time_t)-1) error_msg("bad `%s'", toys.optargs[0]);
85        tv.tv_usec = 0;
86        if (!strftime(toybuf, sizeof(toybuf), format_string, &tm))
87            perror_msg("bad format `%s'", format_string);
88        puts(toybuf);
89        if (settimeofday(&tv, NULL) < 0) perror_msg("cannot set date");
90    }
91}
92