date: factor out date parsing (in preparation for touch -d)

function                                             old     new   delta
parse_datestr                                          -     391    +391
sha512_process_block128                             1283    1310     +27
buffer_fill_and_print                                179     196     +17
nexpr                                                826     840     +14
unzip_main                                          1931    1939      +8
popstring                                            134     140      +6
qrealloc                                              33      36      +3
builtin_umask                                        121     123      +2
evalvar                                             1365    1363      -2
changepath                                           194     192      -2
do_compress                                         1698    1688     -10
hwclock_main                                         340     329     -11
cmdputs                                              414     402     -12
identify                                            4343    4329     -14
date_main                                           1186     687    -499
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 7/7 up/down: 468/-550)          Total: -82 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 54 insertions, 80 deletions

diff --git a/coreutils/date.c b/coreutils/date.c
index 3a536db..7f2a5b3 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -10,8 +10,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
 
-#include "libbb.h"
-
 /* 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 it, as well as
@@ -23,18 +21,51 @@
 
 /* Default input handling to save surprising some people */
 
+/* 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
+ */
+#include "libbb.h"
 
-#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
-#define DATE_OPT_TIMESPEC	0x20
-#define DATE_OPT_HINT		0x40
+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 */
+};
 
 static void maybe_set_utc(int opt)
 {
-	if (opt & DATE_OPT_UTC)
+	if (opt & OPT_UTC)
 		putenv((char*)"TZ=UTC0");
 }
 
@@ -60,7 +91,7 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 	argv += optind;
 	maybe_set_utc(opt);
 
-	if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_TIMESPEC)) {
+	if (ENABLE_FEATURE_DATE_ISOFMT && (opt & OPT_TIMESPEC)) {
 		ifmt = 0; /* default is date */
 		if (isofmt_arg) {
 			static const char isoformats[] ALIGN1 =
@@ -76,8 +107,8 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 		fmt_dt2str = &argv[0][1];	/* Skip over the '+' */
 		argv++;
 	}
-	if (!(opt & (DATE_OPT_SET | DATE_OPT_DATE))) {
-		opt |= DATE_OPT_SET;
+	if (!(opt & (OPT_SET | OPT_DATE))) {
+		opt |= OPT_SET;
 		date_str = argv[0]; /* can be NULL */
 		if (date_str)
 			argv++;
@@ -88,13 +119,14 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 	/* Now we have parsed all the information except the date format
 	   which depends on whether the clock is being set or read */
 
-	if (opt & DATE_OPT_REFERENCE) {
+	if (opt & OPT_REFERENCE) {
 		struct stat statbuf;
 		xstat(filename, &statbuf);
 		tm = statbuf.st_mtime;
-	} else
+	} else {
 		time(&tm);
-	memcpy(&tm_time, localtime(&tm), sizeof(tm_time));
+	}
+	localtime_r(&tm, &tm_time);
 
 	/* If date string is given, update tm_time, and maybe set date */
 	if (date_str != NULL) {
@@ -104,72 +136,14 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 		tm_time.tm_hour = 0;
 
 		/* Process any date input to UNIX time since 1 Jan 1970 */
-		if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_HINT)) {
+		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 {
-			char end = '\0';
-			const char *last_colon = strrchr(date_str, ':');
-
-			if (last_colon != NULL) {
-				/* Parse input and assign appropriately to tm_time */
-
-				if (sscanf(date_str, "%u:%u%c",
-								&tm_time.tm_hour,
-								&tm_time.tm_min,
-								&end) >= 2) {
-					/* no adjustments needed */
-				} else if (sscanf(date_str, "%u.%u-%u:%u%c",
-								&tm_time.tm_mon, &tm_time.tm_mday,
-								&tm_time.tm_hour, &tm_time.tm_min,
-								&end) >= 4) {
-					/* Adjust dates from 1-12 to 0-11 */
-					tm_time.tm_mon -= 1;
-				} else if (sscanf(date_str, "%u.%u.%u-%u:%u%c", &tm_time.tm_year,
-								&tm_time.tm_mon, &tm_time.tm_mday,
-								&tm_time.tm_hour, &tm_time.tm_min,
-								&end) >= 5) {
-					tm_time.tm_year -= 1900; /* Adjust years */
-					tm_time.tm_mon -= 1; /* Adjust dates from 1-12 to 0-11 */
-				} else if (sscanf(date_str, "%u-%u-%u %u:%u%c", &tm_time.tm_year,
-								&tm_time.tm_mon, &tm_time.tm_mday,
-								&tm_time.tm_hour, &tm_time.tm_min,
-								&end) >= 5) {
-					tm_time.tm_year -= 1900; /* Adjust years */
-					tm_time.tm_mon -= 1; /* Adjust dates from 1-12 to 0-11 */
-//TODO: coreutils 6.9 also accepts "YYYY-MM-DD HH" (no minutes)
-				} else {
-					bb_error_msg_and_die(bb_msg_invalid_date, date_str);
-				}
-				if (end == ':') {
-					if (sscanf(last_colon + 1, "%u%c", &tm_time.tm_sec, &end) == 1)
-						end = '\0';
-					/* else end != NUL and we error out */
-				}
-			} else {
-				if (sscanf(date_str, "%2u%2u%2u%2u%u%c", &tm_time.tm_mon,
-							&tm_time.tm_mday, &tm_time.tm_hour, &tm_time.tm_min,
-							&tm_time.tm_year, &end) < 4)
-					bb_error_msg_and_die(bb_msg_invalid_date, date_str);
-				/* 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;
-				if (end == '.') {
-					if (sscanf(strchr(date_str, '.') + 1, "%u%c",
-							&tm_time.tm_sec, &end) == 1)
-						end = '\0';
-					/* else end != NUL and we error out */
-				}
-			}
-			if (end != '\0') {
-				bb_error_msg_and_die(bb_msg_invalid_date, 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_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);
@@ -177,7 +151,7 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 		maybe_set_utc(opt);
 
 		/* if setting time, set it */
-		if ((opt & DATE_OPT_SET) && stime(&tm) < 0) {
+		if ((opt & OPT_SET) && stime(&tm) < 0) {
 			bb_perror_msg("cannot set date");
 		}
 	}
@@ -207,9 +181,9 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 				}
  format_utc:
 				fmt_dt2str[i++] = '%';
-				fmt_dt2str[i] = (opt & DATE_OPT_UTC) ? 'Z' : 'z';
+				fmt_dt2str[i] = (opt & OPT_UTC) ? 'Z' : 'z';
 			}
-		} else if (opt & DATE_OPT_RFC2822) {
+		} else if (opt & OPT_RFC2822) {
 			/* Undo busybox.c for date -R */
 			if (ENABLE_LOCALE_SUPPORT)
 				setlocale(LC_TIME, "C");