coreutils/date.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini date implementation for busybox
   4  *
   5  * by Matthew Grant <grantma@anathoth.gen.nz>
   6  *
   7  * iso-format handling added by Robert Griebl <griebl@gmx.de>
   8  * bugfixes and cleanup by Bernhard Fischer
   9  *
  10  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  11 */
  12
  13 #include "libbb.h"
  14
  15 /* This 'date' command supports only 2 time setting formats,
  16    all the GNU strftime stuff (its in libc, lets use it),
  17    setting time using UTC and displaying it, as well as
  18    an RFC 2822 compliant date output for shell scripting
  19    mail commands */
  20
  21 /* Input parsing code is always bulky - used heavy duty libc stuff as
  22    much as possible, missed out a lot of bounds checking */
  23
  24 /* Default input handling to save surprising some people */
  25
  26
  27 #define DATE_OPT_RFC2822        0x01
  28 #define DATE_OPT_SET            0x02
  29 #define DATE_OPT_UTC            0x04
  30 #define DATE_OPT_DATE           0x08
  31 #define DATE_OPT_REFERENCE      0x10
  32 #define DATE_OPT_TIMESPEC       0x20
  33 #define DATE_OPT_HINT           0x40
  34
  35 static void maybe_set_utc(int opt)
  36 {
  37         if (opt & DATE_OPT_UTC)
  38                 putenv((char*)"TZ=UTC0");
  39 }
  40
  41 int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  42 int date_main(int argc ATTRIBUTE_UNUSED, char **argv)
  43 {
  44         struct tm tm_time;
  45         time_t tm;
  46         unsigned opt;
  47         int ifmt = -1;
  48         char *date_str;
  49         char *fmt_dt2str;
  50         char *fmt_str2dt;
  51         char *filename;
  52         char *isofmt_arg = NULL;
  53
  54         opt_complementary = "d--s:s--d"
  55                 USE_FEATURE_DATE_ISOFMT(":R--I:I--R");
  56         opt = getopt32(argv, "Rs:ud:r:"
  57                         USE_FEATURE_DATE_ISOFMT("I::D:"),
  58                         &date_str, &date_str, &filename
  59                         USE_FEATURE_DATE_ISOFMT(, &isofmt_arg, &fmt_str2dt));
  60         argv += optind;
  61         maybe_set_utc(opt);
  62
  63         if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_TIMESPEC)) {
  64                 ifmt = 0; /* default is date */
  65                 if (isofmt_arg) {
  66                         static const char isoformats[] ALIGN1 =
  67                                 "date\0""hours\0""minutes\0""seconds\0";
  68                         ifmt = index_in_strings(isoformats, isofmt_arg);
  69                         if (ifmt < 0)
  70                                 bb_show_usage();
  71                 }
  72         }
  73
  74         fmt_dt2str = NULL;
  75         if (argv[0] && argv[0][0] == '+') {
  76                 fmt_dt2str = &argv[0][1];       /* Skip over the '+' */
  77                 argv++;
  78         }
  79         if (!(opt & (DATE_OPT_SET | DATE_OPT_DATE))) {
  80                 opt |= DATE_OPT_SET;
  81                 date_str = argv[0]; /* can be NULL */
  82         }
  83
  84         /* Now we have parsed all the information except the date format
  85            which depends on whether the clock is being set or read */
  86
  87         if (opt & DATE_OPT_REFERENCE) {
  88                 struct stat statbuf;
  89                 xstat(filename, &statbuf);
  90                 tm = statbuf.st_mtime;
  91         } else
  92                 time(&tm);
  93         memcpy(&tm_time, localtime(&tm), sizeof(tm_time));
  94
  95         /* If date string is given, update tm_time, and maybe set date */
  96         if (date_str != NULL) {
  97                 /* Zero out fields - take her back to midnight! */
  98                 tm_time.tm_sec = 0;
  99                 tm_time.tm_min = 0;
 100                 tm_time.tm_hour = 0;
 101
 102                 /* Process any date input to UNIX time since 1 Jan 1970 */
 103                 if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_HINT)) {
 104                         if (strptime(date_str, fmt_str2dt, &tm_time) == NULL)
 105                                 bb_error_msg_and_die(bb_msg_invalid_date, date_str);
 106                 } else if (strchr(date_str, ':') != NULL) {
 107                         /* Parse input and assign appropriately to tm_time */
 108
 109                         if (sscanf(date_str, "%d:%d:%d", &tm_time.tm_hour, &tm_time.tm_min,
 110                                                                  &tm_time.tm_sec) == 3) {
 111                                 /* no adjustments needed */
 112                         } else if (sscanf(date_str, "%d:%d", &tm_time.tm_hour,
 113                                                                                 &tm_time.tm_min) == 2) {
 114                                 /* no adjustments needed */
 115                         } else if (sscanf(date_str, "%d.%d-%d:%d:%d", &tm_time.tm_mon,
 116                                                                 &tm_time.tm_mday, &tm_time.tm_hour,
 117                                                                 &tm_time.tm_min, &tm_time.tm_sec) == 5) {
 118                                 /* Adjust dates from 1-12 to 0-11 */
 119                                 tm_time.tm_mon -= 1;
 120                         } else if (sscanf(date_str, "%d.%d-%d:%d", &tm_time.tm_mon,
 121                                                                 &tm_time.tm_mday,
 122                                                                 &tm_time.tm_hour, &tm_time.tm_min) == 4) {
 123                                 /* Adjust dates from 1-12 to 0-11 */
 124                                 tm_time.tm_mon -= 1;
 125                         } else if (sscanf(date_str, "%d.%d.%d-%d:%d:%d", &tm_time.tm_year,
 126                                                                 &tm_time.tm_mon, &tm_time.tm_mday,
 127                                                                 &tm_time.tm_hour, &tm_time.tm_min,
 128                                                                         &tm_time.tm_sec) == 6) {
 129                                 tm_time.tm_year -= 1900;        /* Adjust years */
 130                                 tm_time.tm_mon -= 1;    /* Adjust dates from 1-12 to 0-11 */
 131                         } else if (sscanf(date_str, "%d.%d.%d-%d:%d", &tm_time.tm_year,
 132                                                                 &tm_time.tm_mon, &tm_time.tm_mday,
 133                                                                 &tm_time.tm_hour, &tm_time.tm_min) == 5) {
 134                                 tm_time.tm_year -= 1900;        /* Adjust years */
 135                                 tm_time.tm_mon -= 1;    /* Adjust dates from 1-12 to 0-11 */
 136                         } else {
 137                                 bb_error_msg_and_die(bb_msg_invalid_date, date_str);
 138                         }
 139                 } else {
 140                         int nr;
 141                         char *cp;
 142
 143                         nr = sscanf(date_str, "%2d%2d%2d%2d%d", &tm_time.tm_mon,
 144                                                 &tm_time.tm_mday, &tm_time.tm_hour, &tm_time.tm_min,
 145                                                 &tm_time.tm_year);
 146
 147                         if (nr < 4 || nr > 5) {
 148                                 bb_error_msg_and_die(bb_msg_invalid_date, date_str);
 149                         }
 150
 151                         cp = strchr(date_str, '.');
 152                         if (cp) {
 153                                 nr = sscanf(cp + 1, "%2d", &tm_time.tm_sec);
 154                                 if (nr != 1) {
 155                                         bb_error_msg_and_die(bb_msg_invalid_date, date_str);
 156                                 }
 157                         }
 158
 159                         /* correct for century  - minor Y2K problem here? */
 160                         if (tm_time.tm_year >= 1900) {
 161                                 tm_time.tm_year -= 1900;
 162                         }
 163                         /* adjust date */
 164                         tm_time.tm_mon -= 1;
 165                 }
 166
 167                 /* Correct any day of week and day of year etc. fields */
 168                 tm_time.tm_isdst = -1;  /* Be sure to recheck dst. */
 169                 tm = mktime(&tm_time);
 170                 if (tm < 0) {
 171                         bb_error_msg_and_die(bb_msg_invalid_date, date_str);
 172                 }
 173                 maybe_set_utc(opt);
 174
 175                 /* if setting time, set it */
 176                 if ((opt & DATE_OPT_SET) && stime(&tm) < 0) {
 177                         bb_perror_msg("cannot set date");
 178                 }
 179         }
 180
 181         /* Display output */
 182
 183         /* Deal with format string */
 184         if (fmt_dt2str == NULL) {
 185                 int i;
 186                 fmt_dt2str = xzalloc(32);
 187                 if (ENABLE_FEATURE_DATE_ISOFMT && ifmt >= 0) {
 188                         strcpy(fmt_dt2str, "%Y-%m-%d");
 189                         if (ifmt > 0) {
 190                                 i = 8;
 191                                 fmt_dt2str[i++] = 'T';
 192                                 fmt_dt2str[i++] = '%';
 193                                 fmt_dt2str[i++] = 'H';
 194                                 if (ifmt > 1) {
 195                                         fmt_dt2str[i++] = ':';
 196                                         fmt_dt2str[i++] = '%';
 197                                         fmt_dt2str[i++] = 'M';
 198                                         if (ifmt > 2) {
 199                                                 fmt_dt2str[i++] = ':';
 200                                                 fmt_dt2str[i++] = '%';
 201                                                 fmt_dt2str[i++] = 'S';
 202                                         }
 203                                 }
 204  format_utc:
 205                                 fmt_dt2str[i++] = '%';
 206                                 fmt_dt2str[i] = (opt & DATE_OPT_UTC) ? 'Z' : 'z';
 207                         }
 208                 } else if (opt & DATE_OPT_RFC2822) {
 209                         /* Undo busybox.c for date -R */
 210                         if (ENABLE_LOCALE_SUPPORT)
 211                                 setlocale(LC_TIME, "C");
 212                         strcpy(fmt_dt2str, "%a, %d %b %Y %H:%M:%S ");
 213                         i = 22;
 214                         goto format_utc;
 215                 } else /* default case */
 216                         fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
 217         }
 218
 219 #define date_buf bb_common_bufsiz1
 220         if (*fmt_dt2str == '\0') {
 221                 /* With no format string, just print a blank line */
 222                 date_buf[0] = '\0';
 223         } else {
 224                 /* Handle special conversions */
 225                 if (strncmp(fmt_dt2str, "%f", 2) == 0) {
 226                         fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
 227                 }
 228
 229                 /* Generate output string */
 230                 strftime(date_buf, sizeof(date_buf), fmt_dt2str, &tm_time);
 231         }
 232         puts(date_buf);
 233
 234         return EXIT_SUCCESS;
 235 }