Bump version to 1.32.0
[oweals/busybox.git] / coreutils / date.c
index 9583a003653d6859000cb98bd6ee8034249d18a6..b9b7fd2cbde9abda099a60274e313a48f15eb47e 100644 (file)
  * by Matthew Grant <grantma@anathoth.gen.nz>
  *
  * iso-format handling added by Robert Griebl <griebl@gmx.de>
+ * bugfixes and cleanup by Bernhard Reutner-Fischer
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
-*/
-
-#include <stdlib.h>
-#include <errno.h>
-#include <sys/time.h>
-#include <unistd.h>
-#include <time.h>
-#include <stdio.h>
-#include <string.h>
-#include "busybox.h"
-
-
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
 /* This 'date' command supports only 2 time setting formats,
    all the GNU strftime stuff (its in libc, lets use it),
-   setting time using UTC and displaying int, as well as
-   an RFC 822 complient date output for shell scripting
+   setting time using UTC and displaying it, as well as
+   an RFC 2822 compliant date output for shell scripting
    mail commands */
 
 /* Input parsing code is always bulky - used heavy duty libc stuff as
    much as possible, missed out a lot of bounds checking */
 
-/* Default input handling to save surprising some people */
-
-static struct tm *date_conv_time(struct tm *tm_time, const char *t_string)
-{
-       int nr;
-       char *cp;
-
-       nr = sscanf(t_string, "%2d%2d%2d%2d%d", &(tm_time->tm_mon),
-                               &(tm_time->tm_mday), &(tm_time->tm_hour), &(tm_time->tm_min),
-                               &(tm_time->tm_year));
-
-       if (nr < 4 || nr > 5) {
-               bb_error_msg_and_die(bb_msg_invalid_date, t_string);
-       }
-
-       cp = strchr(t_string, '.');
-       if (cp) {
-               nr = sscanf(cp + 1, "%2d", &(tm_time->tm_sec));
-               if (nr != 1) {
-                       bb_error_msg_and_die(bb_msg_invalid_date, t_string);
-               }
-       }
-
-       /* correct for century  - minor Y2K problem here? */
-       if (tm_time->tm_year >= 1900) {
-               tm_time->tm_year -= 1900;
-       }
-       /* adjust date */
-       tm_time->tm_mon -= 1;
-
-       return (tm_time);
-
-}
+//config:config DATE
+//config:      bool "date (7 kb)"
+//config:      default y
+//config:      help
+//config:      date is used to set the system date or display the
+//config:      current time in the given format.
+//config:
+//config:config FEATURE_DATE_ISOFMT
+//config:      bool "Enable ISO date format output (-I)"
+//config:      default y
+//config:      depends on DATE
+//config:      help
+//config:      Enable option (-I) to output an ISO-8601 compliant
+//config:      date/time string.
+//config:
+//config:config FEATURE_DATE_NANO
+//config:      bool "Support %[num]N nanosecond format specifier"
+//config:      default n # stat's nanosecond field is a bit non-portable
+//config:      depends on DATE
+//config:      select PLATFORM_LINUX
+//config:      help
+//config:      Support %[num]N format specifier. Adds ~250 bytes of code.
+//config:
+//config:config FEATURE_DATE_COMPAT
+//config:      bool "Support weird 'date MMDDhhmm[[YY]YY][.ss]' format"
+//config:      default y
+//config:      depends on DATE
+//config:      help
+//config:      System time can be set by 'date -s DATE' and simply 'date DATE',
+//config:      but formats of DATE string are different. 'date DATE' accepts
+//config:      a rather weird MMDDhhmm[[YY]YY][.ss] format with completely
+//config:      unnatural placement of year between minutes and seconds.
+//config:      date -s (and other commands like touch -d) use more sensible
+//config:      formats (for one, ISO format YYYY-MM-DD hh:mm:ss.ssssss).
+//config:
+//config:      With this option off, 'date DATE' and 'date -s DATE' support
+//config:      the same format. With it on, 'date DATE' additionally supports
+//config:      MMDDhhmm[[YY]YY][.ss] format.
+
+//applet:IF_DATE(APPLET_NOEXEC(date, date, BB_DIR_BIN, BB_SUID_DROP, date))
+/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
+
+//kbuild:lib-$(CONFIG_DATE) += date.o
+
+/* GNU coreutils 6.9 man page:
+ * date [OPTION]... [+FORMAT]
+ * date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
+ * -d, --date=STRING
+ *      display time described by STRING, not 'now'
+ * -f, --file=DATEFILE
+ *      like --date once for each line of DATEFILE
+ * -r, --reference=FILE
+ *      display the last modification time of FILE
+ * -R, --rfc-2822
+ *      output date and time in RFC 2822 format.
+ *      Example: Mon, 07 Aug 2006 12:34:56 -0600
+ * --rfc-3339=TIMESPEC
+ *      output date and time in RFC 3339 format.
+ *      TIMESPEC='date', 'seconds', or 'ns'
+ *      Date and time components are separated by a single space:
+ *      2006-08-07 12:34:56-06:00
+ * -s, --set=STRING
+ *      set time described by STRING
+ * -u, --utc, --universal
+ *      print or set Coordinated Universal Time
+ *
+ * Busybox:
+ * long options are not supported
+ * -f is not supported
+ * -I seems to roughly match --rfc-3339, but -I has _optional_ param
+ *    (thus "-I seconds" doesn't work, only "-Iseconds"),
+ *    and does not support -Ins
+ * -D FMT is a bbox extension for _input_ conversion of -d DATE
+ */
+
+//usage:#define date_trivial_usage
+//usage:       "[OPTIONS] [+FMT] [TIME]"
+//usage:#define date_full_usage "\n\n"
+//usage:       "Display time (using +FMT), or set time\n"
+//usage:       IF_NOT_LONG_OPTS(
+//usage:     "\n       [-s] TIME       Set time to TIME"
+//usage:     "\n       -u              Work in UTC (don't convert to local time)"
+//usage:     "\n       -R              Output RFC-2822 compliant date string"
+//usage:       ) IF_LONG_OPTS(
+//usage:     "\n       [-s,--set] TIME Set time to TIME"
+//usage:     "\n       -u,--utc        Work in UTC (don't convert to local time)"
+//usage:     "\n       -R,--rfc-2822   Output RFC-2822 compliant date string"
+//usage:       )
+//usage:       IF_FEATURE_DATE_ISOFMT(
+//usage:     "\n       -I[SPEC]        Output ISO-8601 compliant date string"
+//usage:     "\n                       SPEC='date' (default) for date only,"
+//usage:     "\n                       'hours', 'minutes', or 'seconds' for date and"
+//usage:     "\n                       time to the indicated precision"
+//usage:       )
+//usage:       IF_NOT_LONG_OPTS(
+//usage:     "\n       -r FILE         Display last modification time of FILE"
+//usage:     "\n       -d TIME         Display TIME, not 'now'"
+//usage:       ) IF_LONG_OPTS(
+//usage:     "\n       -r,--reference FILE     Display last modification time of FILE"
+//usage:     "\n       -d,--date TIME  Display TIME, not 'now'"
+//usage:       )
+//usage:       IF_FEATURE_DATE_ISOFMT(
+//usage:     "\n       -D FMT          Use FMT (strptime format) for -d TIME conversion"
+//usage:       )
+//usage:     "\n"
+//usage:     "\nRecognized TIME formats:"
+//usage:     "\n       hh:mm[:ss]"
+//usage:     "\n       [YYYY.]MM.DD-hh:mm[:ss]"
+//usage:     "\n       YYYY-MM-DD hh:mm[:ss]"
+//usage:     "\n       [[[[[YY]YY]MM]DD]hh]mm[.ss]"
+//usage:       IF_FEATURE_DATE_COMPAT(
+//usage:     "\n       'date TIME' form accepts MMDDhhmm[[YY]YY][.ss] instead"
+//usage:       )
+//usage:
+//usage:#define date_example_usage
+//usage:       "$ date\n"
+//usage:       "Wed Apr 12 18:52:41 MDT 2000\n"
+
+#include "libbb.h"
+#include "common_bufsiz.h"
+#if ENABLE_FEATURE_DATE_NANO
+# include <sys/syscall.h>
+#endif
 
+enum {
+       OPT_RFC2822   = (1 << 0), /* R */
+       OPT_SET       = (1 << 1), /* s */
+       OPT_UTC       = (1 << 2), /* u */
+       OPT_DATE      = (1 << 3), /* d */
+       OPT_REFERENCE = (1 << 4), /* r */
+       OPT_TIMESPEC  = (1 << 5) * ENABLE_FEATURE_DATE_ISOFMT, /* I */
+       OPT_HINT      = (1 << 6) * ENABLE_FEATURE_DATE_ISOFMT, /* D */
+};
+
+#if ENABLE_LONG_OPTS
+static const char date_longopts[] ALIGN1 =
+               "rfc-822\0"   No_argument       "R"
+               "rfc-2822\0"  No_argument       "R"
+               "set\0"       Required_argument "s"
+               "utc\0"       No_argument       "u"
+       /*      "universal\0" No_argument       "u" */
+               "date\0"      Required_argument "d"
+               "reference\0" Required_argument "r"
+               ;
+#endif
 
-/* The new stuff for LRP */
+/* We are a NOEXEC applet.
+ * Obstacles to NOFORK:
+ * - we change env
+ * - xasprintf result not freed
+ * - after xasprintf we use other xfuncs
+ */
 
-static struct tm *date_conv_ftime(struct tm *tm_time, const char *t_string)
+static void maybe_set_utc(int opt)
 {
-       struct tm t;
-
-       /* Parse input and assign appropriately to tm_time */
-
-       if (t =
-               *tm_time, sscanf(t_string, "%d:%d:%d", &t.tm_hour, &t.tm_min,
-                                                &t.tm_sec) == 3) {
-               /* no adjustments needed */
-       } else if (t =
-                          *tm_time, sscanf(t_string, "%d:%d", &t.tm_hour,
-                                                               &t.tm_min) == 2) {
-               /* no adjustments needed */
-       } else if (t =
-                          *tm_time, sscanf(t_string, "%d.%d-%d:%d:%d", &t.tm_mon,
-                                                               &t.tm_mday, &t.tm_hour, &t.tm_min,
-                                                               &t.tm_sec) == 5) {
-               /* Adjust dates from 1-12 to 0-11 */
-               t.tm_mon -= 1;
-       } else if (t =
-                          *tm_time, sscanf(t_string, "%d.%d-%d:%d", &t.tm_mon,
-                                                               &t.tm_mday, &t.tm_hour, &t.tm_min) == 4) {
-               /* Adjust dates from 1-12 to 0-11 */
-               t.tm_mon -= 1;
-       } else if (t =
-                          *tm_time, sscanf(t_string, "%d.%d.%d-%d:%d:%d", &t.tm_year,
-                                                               &t.tm_mon, &t.tm_mday, &t.tm_hour, &t.tm_min,
-                                                               &t.tm_sec) == 6) {
-               t.tm_year -= 1900;      /* Adjust years */
-               t.tm_mon -= 1;  /* Adjust dates from 1-12 to 0-11 */
-       } else if (t =
-                          *tm_time, sscanf(t_string, "%d.%d.%d-%d:%d", &t.tm_year,
-                                                               &t.tm_mon, &t.tm_mday, &t.tm_hour,
-                                                               &t.tm_min) == 5) {
-               t.tm_year -= 1900;      /* Adjust years */
-               t.tm_mon -= 1;  /* Adjust dates from 1-12 to 0-11 */
-       } else {
-               bb_error_msg_and_die(bb_msg_invalid_date, t_string);
-       }
-       *tm_time = t;
-       return (tm_time);
+       if (opt & OPT_UTC)
+               putenv((char*)"TZ=UTC0");
 }
 
-#define DATE_OPT_RFC2822       0x01
-#define DATE_OPT_SET           0x02
-#define DATE_OPT_UTC           0x04
-#define DATE_OPT_DATE          0x08
-#define DATE_OPT_REFERENCE     0x10
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-# define DATE_OPT_TIMESPEC     0x20
-#endif
-
-int date_main(int argc, char **argv)
+int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int date_main(int argc UNUSED_PARAM, char **argv)
 {
-       char *date_str = NULL;
-       char *date_fmt = NULL;
-       int set_time;
-       int utc;
-       int use_arg = 0;
-       time_t tm;
-       unsigned long opt;
+       struct timespec ts;
        struct tm tm_time;
-       char *filename = NULL;
-
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-       int ifmt = 0;
-       char *isofmt_arg;
-
-# define GETOPT_ISOFMT  "I::"
-#else
-# define GETOPT_ISOFMT
-#endif
-       bb_opt_complementally = "!d~ds:s~ds";
-       opt = bb_getopt_ulflags(argc, argv, "Rs:ud:r:" GETOPT_ISOFMT,
-                                       &date_str, &date_str, &filename
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-                                       , &isofmt_arg
-#endif
-                                       );
-       set_time = opt & DATE_OPT_SET;
-       utc = opt & DATE_OPT_UTC;
-       if ((utc) && (putenv("TZ=UTC0") != 0)) {
-               bb_error_msg_and_die(bb_msg_memory_exhausted);
+       char buf_fmt_dt2str[64];
+       unsigned opt;
+       int ifmt = -1;
+       char *date_str;
+       char *fmt_dt2str;
+       char *fmt_str2dt;
+       char *filename;
+       char *isofmt_arg = NULL;
+
+       opt = getopt32long(argv, "^"
+                       "Rs:ud:r:"
+                       IF_FEATURE_DATE_ISOFMT("I::D:")
+                       "\0"
+                       "d--s:s--d"
+                       IF_FEATURE_DATE_ISOFMT(":R--I:I--R"),
+                       date_longopts,
+                       &date_str, &date_str, &filename
+                       IF_FEATURE_DATE_ISOFMT(, &isofmt_arg, &fmt_str2dt)
+       );
+       argv += optind;
+
+       maybe_set_utc(opt);
+
+       if (ENABLE_FEATURE_DATE_ISOFMT && (opt & OPT_TIMESPEC)) {
+               ifmt = 0; /* default is date */
+               if (isofmt_arg) {
+                       static const char isoformats[] ALIGN1 =
+                               "date\0""hours\0""minutes\0""seconds\0"; /* ns? */
+                       ifmt = index_in_substrings(isoformats, isofmt_arg);
+                       if (ifmt < 0)
+                               bb_show_usage();
+               }
        }
-       use_arg = opt & DATE_OPT_DATE;
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-       if(opt & DATE_OPT_TIMESPEC) {
-               if (!isofmt_arg) {
-                       ifmt = 1;
-               } else {
-                       int ifmt_len = bb_strlen(isofmt_arg);
 
-                       if ((ifmt_len <= 4)
-                               && (strncmp(isofmt_arg, "date", ifmt_len) == 0)) {
-                               ifmt = 1;
-                       } else if ((ifmt_len <= 5)
-                                  && (strncmp(isofmt_arg, "hours", ifmt_len) == 0)) {
-                               ifmt = 2;
-                       } else if ((ifmt_len <= 7)
-                                  && (strncmp(isofmt_arg, "minutes", ifmt_len) == 0)) {
-                               ifmt = 3;
-                       } else if ((ifmt_len <= 7)
-                                  && (strncmp(isofmt_arg, "seconds", ifmt_len) == 0)) {
-                               ifmt = 4;
-                       }
-               }
-               if (!ifmt) {
-                       bb_show_usage();
-               }
+       fmt_dt2str = NULL;
+       if (argv[0] && argv[0][0] == '+') {
+               fmt_dt2str = &argv[0][1]; /* skip over the '+' */
+               argv++;
        }
+       if (!(opt & (OPT_SET | OPT_DATE))) {
+               opt |= OPT_SET;
+               date_str = argv[0]; /* can be NULL */
+               if (date_str) {
+#if ENABLE_FEATURE_DATE_COMPAT
+                       int len = strspn(date_str, "0123456789");
+                       if (date_str[len] == '\0'
+                        || (date_str[len] == '.'
+                           && isdigit(date_str[len+1])
+                           && isdigit(date_str[len+2])
+                           && date_str[len+3] == '\0'
+                           )
+                       ) {
+                               /* Dreaded MMDDhhmm[[CC]YY][.ss] format!
+                                * It does not match -d or -s format.
+                                * Some users actually do use it.
+                                */
+                               len -= 8;
+                               if (len < 0 || len > 4 || (len & 1))
+                                       bb_error_msg_and_die(bb_msg_invalid_date, date_str);
+                               if (len != 0) { /* move YY or CCYY to front */
+                                       char buf[4];
+                                       memcpy(buf, date_str + 8, len);
+                                       memmove(date_str + len, date_str, 8);
+                                       memcpy(date_str, buf, len);
+                               }
+                       }
 #endif
-
-       if ((date_fmt == NULL) && (optind < argc) && (argv[optind][0] == '+')) {
-               date_fmt = &argv[optind][1];    /* Skip over the '+' */
-       } else if (date_str == NULL) {
-               set_time = 1;
-               date_str = argv[optind];
+                       argv++;
+               }
        }
+       if (*argv)
+               bb_show_usage();
 
        /* Now we have parsed all the information except the date format
-          which depends on whether the clock is being set or read */
+        * which depends on whether the clock is being set or read */
 
-       if(filename) {
+       if (opt & OPT_REFERENCE) {
                struct stat statbuf;
-               if(stat(filename,&statbuf))
-                       bb_perror_msg_and_die("File '%s' not found.\n",filename);
-               tm=statbuf.st_mtime;
-       } else time(&tm);
-       memcpy(&tm_time, localtime(&tm), sizeof(tm_time));
-       /* Zero out fields - take her back to midnight! */
+               xstat(filename, &statbuf);
+               ts.tv_sec = statbuf.st_mtime;
+#if ENABLE_FEATURE_DATE_NANO
+               ts.tv_nsec = statbuf.st_mtim.tv_nsec;
+               /* Some toolchains use .st_mtimensec instead of st_mtim.tv_nsec.
+                * If you need #define _SVID_SOURCE 1 to enable st_mtim.tv_nsec,
+                * drop a mail to project mailing list please
+                */
+#endif
+       } else {
+#if ENABLE_FEATURE_DATE_NANO
+               clock_gettime(CLOCK_REALTIME, &ts);
+#else
+               time(&ts.tv_sec);
+#endif
+       }
+#if !ENABLE_FEATURE_DATE_NANO
+       ts.tv_nsec = 0;
+#endif
+       localtime_r(&ts.tv_sec, &tm_time);
+
+       /* If date string is given, update tm_time, and maybe set date */
        if (date_str != NULL) {
+               /* Zero out fields - take her back to midnight! */
                tm_time.tm_sec = 0;
                tm_time.tm_min = 0;
                tm_time.tm_hour = 0;
 
                /* Process any date input to UNIX time since 1 Jan 1970 */
-               if (strchr(date_str, ':') != NULL) {
-                       date_conv_ftime(&tm_time, date_str);
+               if (ENABLE_FEATURE_DATE_ISOFMT && (opt & OPT_HINT)) {
+                       if (strptime(date_str, fmt_str2dt, &tm_time) == NULL)
+                               bb_error_msg_and_die(bb_msg_invalid_date, date_str);
                } else {
-                       date_conv_time(&tm_time, date_str);
+                       parse_datestr(date_str, &tm_time);
                }
 
                /* Correct any day of week and day of year etc. fields */
-               tm_time.tm_isdst = -1;  /* Be sure to recheck dst. */
-               tm = mktime(&tm_time);
-               if (tm < 0) {
-                       bb_error_msg_and_die(bb_msg_invalid_date, date_str);
-               }
-               if (utc && (putenv("TZ=UTC0") != 0)) {
-                       bb_error_msg_and_die(bb_msg_memory_exhausted);
-               }
+               /* Be sure to recheck dst (but not if date is time_t format) */
+               if (date_str[0] != '@')
+                       tm_time.tm_isdst = -1;
+               ts.tv_sec = validate_tm_time(date_str, &tm_time);
+               ts.tv_nsec = 0;
 
                /* if setting time, set it */
-               if (set_time && (stime(&tm) < 0)) {
-                       bb_perror_msg("cannot set date");
+               if ((opt & OPT_SET) && clock_settime(CLOCK_REALTIME, &ts) < 0) {
+                       bb_simple_perror_msg("can't set date");
                }
        }
 
        /* Display output */
 
        /* Deal with format string */
-       if (date_fmt == NULL) {
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-               switch (ifmt) {
-               case 4:
-                       date_fmt = utc ? "%Y-%m-%dT%H:%M:%SZ" : "%Y-%m-%dT%H:%M:%S%z";
-                       break;
-               case 3:
-                       date_fmt = utc ? "%Y-%m-%dT%H:%MZ" : "%Y-%m-%dT%H:%M%z";
-                       break;
-               case 2:
-                       date_fmt = utc ? "%Y-%m-%dT%HZ" : "%Y-%m-%dT%H%z";
-                       break;
-               case 1:
-                       date_fmt = "%Y-%m-%d";
-                       break;
-               case 0:
-               default:
-#endif
-                       date_fmt = (opt & DATE_OPT_RFC2822 ?
-                                       (utc ? "%a, %d %b %Y %H:%M:%S GMT" :
-                                       "%a, %d %b %Y %H:%M:%S %z") :
-                                       "%a %b %e %H:%M:%S %Z %Y");
-
-#ifdef CONFIG_FEATURE_DATE_ISOFMT
-                       break;
+       if (fmt_dt2str == NULL) {
+               int i;
+               fmt_dt2str = buf_fmt_dt2str;
+               if (ENABLE_FEATURE_DATE_ISOFMT && ifmt >= 0) {
+                       /* -I[SPEC]: 0:date 1:hours 2:minutes 3:seconds */
+                       strcpy(fmt_dt2str, "%Y-%m-%dT%H:%M:%S");
+                       i = 8 + 3 * ifmt;
+                       if (ifmt != 0) {
+                               /* TODO: if (ifmt==4) i += sprintf(&fmt_dt2str[i], ",%09u", nanoseconds); */
+ format_utc:
+                               fmt_dt2str[i++] = '%';
+                               fmt_dt2str[i++] = (opt & OPT_UTC) ? 'Z' : 'z';
+                       }
+                       fmt_dt2str[i] = '\0';
+               } else if (opt & OPT_RFC2822) {
+                       /* -R. undo busybox.c setlocale */
+                       if (ENABLE_LOCALE_SUPPORT)
+                               setlocale(LC_TIME, "C");
+                       strcpy(fmt_dt2str, "%a, %d %b %Y %H:%M:%S ");
+                       i = sizeof("%a, %d %b %Y %H:%M:%S ")-1;
+                       goto format_utc;
+               } else { /* default case */
+                       fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
                }
-#endif
-       } else if (*date_fmt == '\0') {
-               /* Imitate what GNU 'date' does with NO format string! */
-               printf("\n");
-               return EXIT_SUCCESS;
        }
+#if ENABLE_FEATURE_DATE_NANO
+       else {
+               /* User-specified fmt_dt2str */
+               /* Search for and process "%N" */
+               char *p = fmt_dt2str;
+               while ((p = strchr(p, '%')) != NULL) {
+                       int n, m;
+                       unsigned pres, scale;
+
+                       p++;
+                       if (*p == '%') {
+                               p++;
+                               continue;
+                       }
+                       n = strspn(p, "0123456789");
+                       if (p[n] != 'N') {
+                               p += n;
+                               continue;
+                       }
+                       /* We have "%[nnn]N" */
+                       p[-1] = '\0';
+                       p[n] = '\0';
+                       scale = 1;
+                       pres = 9;
+                       if (n) {
+                               pres = xatoi_positive(p);
+                               if (pres == 0)
+                                       pres = 9;
+                               m = 9 - pres;
+                               while (--m >= 0)
+                                       scale *= 10;
+                       }
 
-       /* Handle special conversions */
-
-       if (strncmp(date_fmt, "%f", 2) == 0) {
-               date_fmt = "%Y.%m.%d-%H:%M:%S";
+                       m = p - fmt_dt2str;
+                       p += n + 1;
+                       fmt_dt2str = xasprintf("%s%0*u%s", fmt_dt2str, pres, (unsigned)ts.tv_nsec / scale, p);
+                       p = fmt_dt2str + m;
+               }
        }
+#endif
 
-       {
-               /* Print OUTPUT (after ALL that!) */
-               RESERVE_CONFIG_BUFFER(t_buff, 201);
-               strftime(t_buff, 200, date_fmt, &tm_time);
-               puts(t_buff);
-               RELEASE_CONFIG_BUFFER(t_buff);
+#define date_buf bb_common_bufsiz1
+       setup_common_bufsiz();
+       if (*fmt_dt2str == '\0') {
+               /* With no format string, just print a blank line */
+               date_buf[0] = '\0';
+       } else {
+               /* Handle special conversions */
+               if (is_prefixed_with(fmt_dt2str, "%f")) {
+                       fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
+               }
+               /* Generate output string */
+               strftime(date_buf, COMMON_BUFSIZE, fmt_dt2str, &tm_time);
        }
+       puts(date_buf);
 
        return EXIT_SUCCESS;
 }