1 files changed, 98 insertions, 6 deletions

diff --git a/coreutils/date.c b/coreutils/date.c
index 4e5b3b0b8..3d78a5336 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -51,6 +51,47 @@
  *    and does not support -Ins
  * -D FMT is a bbox extension for _input_ conversion of -d DATE
  */
+
+//kbuild:lib-$(CONFIG_DATE) += date.o
+
+//config:config DATE
+//config:       bool "date"
+//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
+//config:       depends on DATE
+//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' is 'date -s DATE' support
+//config:         the same format. With it on, 'date DATE' additionally supports
+//config:         MMDDhhmm[[YY]YY][.ss] format.
+
 #include "libbb.h"
 
 enum {
@@ -84,9 +125,9 @@ static const char date_longopts[] ALIGN1 =
 int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int date_main(int argc UNUSED_PARAM, char **argv)
 {
+        struct timespec ts;
         struct tm tm_time;
         char buf_fmt_dt2str[64];
-        time_t tm;
         unsigned opt;
         int ifmt = -1;
         char *date_str;
@@ -161,11 +202,22 @@ int date_main(int argc UNUSED_PARAM, char **argv)
         if (opt & OPT_REFERENCE) {
                 struct stat statbuf;
                 xstat(filename, &statbuf);
-                tm = statbuf.st_mtime;
+                ts.tv_sec = statbuf.st_mtime;
+#if ENABLE_FEATURE_DATE_NANO
+# if defined __GLIBC__ && !defined __UCLIBC__
+                ts.tv_nsec = statbuf.st_mtim.tv_nsec;
+# else
+                ts.tv_nsec = statbuf.st_mtimensec;
+# endif
+#endif
         } else {
-                time(&tm);
+#if ENABLE_FEATURE_DATE_NANO
+                clock_gettime(CLOCK_REALTIME, &ts);
+#else
+                time(&ts.tv_nsec);
+#endif
         }
-        localtime_r(&tm, &tm_time);
+        localtime_r(&ts.tv_sec, &tm_time);
 
         /* If date string is given, update tm_time, and maybe set date */
         if (date_str != NULL) {
@@ -184,12 +236,12 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 
                 /* Correct any day of week and day of year etc. fields */
                 tm_time.tm_isdst = -1;  /* Be sure to recheck dst */
-                tm = validate_tm_time(date_str, &tm_time);
+                ts.tv_sec = validate_tm_time(date_str, &tm_time);
 
                 maybe_set_utc(opt);
 
                 /* if setting time, set it */
-                if ((opt & OPT_SET) && stime(&tm) < 0) {
+                if ((opt & OPT_SET) && stime(&ts.tv_sec) < 0) {
                         bb_perror_msg("can't set date");
                 }
         }
@@ -222,6 +274,46 @@ int date_main(int argc UNUSED_PARAM, char **argv)
                         fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
                 }
         }
+#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_u(p);
+                                if (pres == 0)
+                                        pres = 9;
+                                m = 9 - pres;
+                                while (--m >= 0)
+                                        scale *= 10;
+                        }
+
+                        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
 
 #define date_buf bb_common_bufsiz1
         if (*fmt_dt2str == '\0') {