date: make help text more understandable; small shrink

   text    data     bss     dec     hex filename
 799025     641    7380  807046   c5086 busybox_old
 799009     641    7380  807030   c5076 busybox_unstripped

1 files changed, 51 insertions, 53 deletions

diff --git a/coreutils/date.c b/coreutils/date.c
index a8e339333..064f758e2 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -39,70 +39,70 @@ static void maybe_set_utc(int opt)
 }
 
 int date_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int date_main(int argc, char **argv)
+int date_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
-        time_t tm;
         struct tm tm_time;
+        time_t tm;
         unsigned opt;
         int ifmt = -1;
-        char *date_str = NULL;
-        char *date_fmt = NULL;
-        char *filename = NULL;
-        char *isofmt_arg;
-        char *hintfmt_arg;
+        char *date_str;
+        char *fmt_dt2str;
+        char *fmt_str2dt;
+        char *filename;
+        char *isofmt_arg = NULL;
 
         opt_complementary = "d--s:s--d"
                 USE_FEATURE_DATE_ISOFMT(":R--I:I--R");
         opt = getopt32(argv, "Rs:ud:r:"
                         USE_FEATURE_DATE_ISOFMT("I::D:"),
                         &date_str, &date_str, &filename
-                        USE_FEATURE_DATE_ISOFMT(, &isofmt_arg, &hintfmt_arg));
+                        USE_FEATURE_DATE_ISOFMT(, &isofmt_arg, &fmt_str2dt));
+        argv += optind;
         maybe_set_utc(opt);
 
         if (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_TIMESPEC)) {
-                if (!isofmt_arg) {
-                        ifmt = 0; /* default is date */
-                } else {
-                        static const char *const isoformats[] = {
-                                "date", "hours", "minutes", "seconds"
-                        };
-
-                        for (ifmt = 0; ifmt < 4; ifmt++)
-                                if (!strcmp(isofmt_arg, isoformats[ifmt]))
-                                        goto found;
-                        /* parse error */
-                        bb_show_usage();
- found: ;
+                ifmt = 0; /* default is date */
+                if (isofmt_arg) {
+                        static const char isoformats[] ALIGN1 =
+                                "date\0""hours\0""minutes\0""seconds\0";
+                        ifmt = index_in_strings(isoformats, isofmt_arg);
+                        if (ifmt < 0)
+                                bb_show_usage();
                 }
         }
 
-        /* XXX, date_fmt == NULL from this always */
-        if ((date_fmt == NULL) && (optind < argc) && (argv[optind][0] == '+')) {
-                date_fmt = &argv[optind][1];    /* Skip over the '+' */
-        } else if (date_str == NULL) {
+        fmt_dt2str = NULL;
+        if (argv[0] && argv[0][0] == '+') {
+                fmt_dt2str = &argv[0][1];       /* Skip over the '+' */
+                argv++;
+        }
+        if (!(opt & (DATE_OPT_SET | DATE_OPT_DATE))) {
                 opt |= DATE_OPT_SET;
-                date_str = argv[optind];
+                date_str = argv[0]; /* can be NULL */
         }
 
         /* Now we have parsed all the information except the date format
            which depends on whether the clock is being set or read */
 
-        if (filename) {
+        if (opt & DATE_OPT_REFERENCE) {
                 struct stat statbuf;
                 xstat(filename, &statbuf);
                 tm = statbuf.st_mtime;
         } else
                 time(&tm);
         memcpy(&tm_time, localtime(&tm), sizeof(tm_time));
-        /* Zero out fields - take her back to midnight! */
+
+        /* 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 (ENABLE_FEATURE_DATE_ISOFMT && (opt & DATE_OPT_HINT)) {
-                        strptime(date_str, hintfmt_arg, &tm_time);
+                        if (strptime(date_str, fmt_str2dt, &tm_time) == NULL)
+                                bb_error_msg_and_die(bb_msg_invalid_date, date_str);
                 } else if (strchr(date_str, ':') != NULL) {
                         /* Parse input and assign appropriately to tm_time */
 
@@ -181,55 +181,53 @@ int date_main(int argc, char **argv)
         /* Display output */
 
         /* Deal with format string */
-
-        if (date_fmt == NULL) {
+        if (fmt_dt2str == NULL) {
                 int i;
-                date_fmt = xzalloc(32);
+                fmt_dt2str = xzalloc(32);
                 if (ENABLE_FEATURE_DATE_ISOFMT && ifmt >= 0) {
-                        strcpy(date_fmt, "%Y-%m-%d");
+                        strcpy(fmt_dt2str, "%Y-%m-%d");
                         if (ifmt > 0) {
                                 i = 8;
-                                date_fmt[i++] = 'T';
-                                date_fmt[i++] = '%';
-                                date_fmt[i++] = 'H';
+                                fmt_dt2str[i++] = 'T';
+                                fmt_dt2str[i++] = '%';
+                                fmt_dt2str[i++] = 'H';
                                 if (ifmt > 1) {
-                                        date_fmt[i++] = ':';
-                                        date_fmt[i++] = '%';
-                                        date_fmt[i++] = 'M';
-                                }
-                                if (ifmt > 2) {
-                                        date_fmt[i++] = ':';
-                                        date_fmt[i++] = '%';
-                                        date_fmt[i++] = 'S';
+                                        fmt_dt2str[i++] = ':';
+                                        fmt_dt2str[i++] = '%';
+                                        fmt_dt2str[i++] = 'M';
+                                        if (ifmt > 2) {
+                                                fmt_dt2str[i++] = ':';
+                                                fmt_dt2str[i++] = '%';
+                                                fmt_dt2str[i++] = 'S';
+                                        }
                                 }
  format_utc:
-                                date_fmt[i++] = '%';
-                                date_fmt[i] = (opt & DATE_OPT_UTC) ? 'Z' : 'z';
+                                fmt_dt2str[i++] = '%';
+                                fmt_dt2str[i] = (opt & DATE_OPT_UTC) ? 'Z' : 'z';
                         }
                 } else if (opt & DATE_OPT_RFC2822) {
                         /* Undo busybox.c for date -R */
                         if (ENABLE_LOCALE_SUPPORT)
                                 setlocale(LC_TIME, "C");
-                        strcpy(date_fmt, "%a, %d %b %Y %H:%M:%S ");
+                        strcpy(fmt_dt2str, "%a, %d %b %Y %H:%M:%S ");
                         i = 22;
                         goto format_utc;
                 } else /* default case */
-                        date_fmt = (char*)"%a %b %e %H:%M:%S %Z %Y";
+                        fmt_dt2str = (char*)"%a %b %e %H:%M:%S %Z %Y";
         }
 
 #define date_buf bb_common_bufsiz1
-        if (*date_fmt == '\0') {
+        if (*fmt_dt2str == '\0') {
                 /* With no format string, just print a blank line */
                 date_buf[0] = '\0';
         } else {
                 /* Handle special conversions */
-
-                if (strncmp(date_fmt, "%f", 2) == 0) {
-                        date_fmt = (char*)"%Y.%m.%d-%H:%M:%S";
+                if (strncmp(fmt_dt2str, "%f", 2) == 0) {
+                        fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
                 }
 
                 /* Generate output string */
-                strftime(date_buf, sizeof(date_buf), date_fmt, &tm_time);
+                strftime(date_buf, sizeof(date_buf), fmt_dt2str, &tm_time);
         }
         puts(date_buf);