2 * rrd_parsetime.c - parse time for at(1)
3 * Copyright (C) 1993, 1994 Thomas Koenig
5 * modifications for English-language times
6 * Copyright (C) 1993 David Parsons
8 * A lot of modifications and extensions
9 * (including the new syntax being useful for RRDB)
10 * Copyright (C) 1999 Oleg Cherevko (aka Olwi Deer)
12 * severe structural damage inflicted by Tobi Oetiker in 1999
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. The name of the author(s) may not be used to endorse or promote
20 * products derived from this software without specific prior written
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 /* NOTE: nothing in here is thread-safe!!!! Not even the localtime
39 * The BNF-like specification of the time syntax parsed is below:
41 * As usual, [ X ] means that X is optional, { X } means that X may
42 * be either omitted or specified as many times as needed,
43 * alternatives are separated by |, brackets are used for grouping.
44 * (# marks the beginning of comment that extends to the end of line)
46 * TIME-SPECIFICATION ::= TIME-REFERENCE [ OFFSET-SPEC ] |
48 * ( START | END ) OFFSET-SPEC
50 * TIME-REFERENCE ::= NOW | TIME-OF-DAY-SPEC [ DAY-SPEC-1 ] |
51 * [ TIME-OF-DAY-SPEC ] DAY-SPEC-2
53 * TIME-OF-DAY-SPEC ::= NUMBER (':') NUMBER [am|pm] | # HH:MM
54 * 'noon' | 'midnight' | 'teatime'
56 * DAY-SPEC-1 ::= NUMBER '/' NUMBER '/' NUMBER | # MM/DD/[YY]YY
57 * NUMBER '.' NUMBER '.' NUMBER | # DD.MM.[YY]YY
58 * NUMBER # Seconds since 1970
61 * DAY-SPEC-2 ::= MONTH-NAME NUMBER [NUMBER] | # Month DD [YY]YY
62 * 'yesterday' | 'today' | 'tomorrow' |
66 * OFFSET-SPEC ::= '+'|'-' NUMBER TIME-UNIT { ['+'|'-'] NUMBER TIME-UNIT }
68 * TIME-UNIT ::= SECONDS | MINUTES | HOURS |
69 * DAYS | WEEKS | MONTHS | YEARS
73 * START ::= 'start' | 's'
76 * SECONDS ::= 'seconds' | 'second' | 'sec' | 's'
77 * MINUTES ::= 'minutes' | 'minute' | 'min' | 'm'
78 * HOURS ::= 'hours' | 'hour' | 'hr' | 'h'
79 * DAYS ::= 'days' | 'day' | 'd'
80 * WEEKS ::= 'weeks' | 'week' | 'wk' | 'w'
81 * MONTHS ::= 'months' | 'month' | 'mon' | 'm'
82 * YEARS ::= 'years' | 'year' | 'yr' | 'y'
84 * MONTH-NAME ::= 'jan' | 'january' | 'feb' | 'february' | 'mar' | 'march' |
85 * 'apr' | 'april' | 'may' | 'jun' | 'june' | 'jul' | 'july' |
86 * 'aug' | 'august' | 'sep' | 'september' | 'oct' | 'october' |
87 * 'nov' | 'november' | 'dec' | 'december'
89 * DAY-OF-WEEK ::= 'sunday' | 'sun' | 'monday' | 'mon' | 'tuesday' | 'tue' |
90 * 'wednesday' | 'wed' | 'thursday' | 'thu' | 'friday' | 'fri' |
94 * As you may note, there is an ambiguity with respect to
95 * the 'm' time unit (which can mean either minutes or months).
96 * To cope with this, code tries to read users mind :) by applying
97 * certain heuristics. There are two of them:
99 * 1. If 'm' is used in context of (i.e. right after the) years,
100 * months, weeks, or days it is assumed to mean months, while
101 * in the context of hours, minutes, and seconds it means minutes.
102 * (e.g., in -1y6m or +3w1m 'm' means 'months', while in
103 * -3h20m or +5s2m 'm' means 'minutes')
105 * 2. Out of context (i.e. right after the '+' or '-' sign) the
106 * meaning of 'm' is guessed from the number it directly follows.
107 * Currently, if the number absolute value is below 25 it is assumed
108 * that 'm' means months, otherwise it is treated as minutes.
109 * (e.g., -25m == -25 minutes, while +24m == +24 months)
117 #include "rrd_tool.h"
120 /* Structures and unions */
123 MIDNIGHT, NOON, TEATIME,
124 PM, AM, YESTERDAY, TODAY, TOMORROW, NOW, START, END,
125 SECONDS, MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS,
127 NUMBER, PLUS, MINUS, DOT, COLON, SLASH, ID, JUNK,
128 JAN, FEB, MAR, APR, MAY, JUN,
129 JUL, AUG, SEP, OCT, NOV, DEC,
130 SUN, MON, TUE, WED, THU, FRI, SAT
133 /* the below is for plus_minus() */
134 #define PREVIOUS_OP (-1)
136 /* parse translation table - table driven parsers can be your FRIEND!
138 struct SpecialToken {
139 char *name; /* token name */
140 int value; /* token id */
142 static const struct SpecialToken VariousWords[] = {
143 {"midnight", MIDNIGHT}, /* 00:00:00 of today or tomorrow */
144 {"noon", NOON}, /* 12:00:00 of today or tomorrow */
145 {"teatime", TEATIME}, /* 16:00:00 of today or tomorrow */
146 {"am", AM}, /* morning times for 0-12 clock */
147 {"pm", PM}, /* evening times for 0-12 clock */
148 {"tomorrow", TOMORROW},
149 {"yesterday", YESTERDAY},
196 {NULL, 0} /*** SENTINEL ***/
199 static const struct SpecialToken TimeMultipliers[] = {
200 {"second", SECONDS}, /* seconds multiplier */
201 {"seconds", SECONDS}, /* (pluralized) */
202 {"sec", SECONDS}, /* (generic) */
203 {"s", SECONDS}, /* (short generic) */
204 {"minute", MINUTES}, /* minutes multiplier */
205 {"minutes", MINUTES}, /* (pluralized) */
206 {"min", MINUTES}, /* (generic) */
207 {"m", MONTHS_MINUTES}, /* (short generic) */
208 {"hour", HOURS}, /* hours ... */
209 {"hours", HOURS}, /* (pluralized) */
210 {"hr", HOURS}, /* (generic) */
211 {"h", HOURS}, /* (short generic) */
212 {"day", DAYS}, /* days ... */
213 {"days", DAYS}, /* (pluralized) */
214 {"d", DAYS}, /* (short generic) */
215 {"week", WEEKS}, /* week ... */
216 {"weeks", WEEKS}, /* (pluralized) */
217 {"wk", WEEKS}, /* (generic) */
218 {"w", WEEKS}, /* (short generic) */
219 {"month", MONTHS}, /* week ... */
220 {"months", MONTHS}, /* (pluralized) */
221 {"mon", MONTHS}, /* (generic) */
222 {"year", YEARS}, /* year ... */
223 {"years", YEARS}, /* (pluralized) */
224 {"yr", YEARS}, /* (generic) */
225 {"y", YEARS}, /* (short generic) */
226 {NULL, 0} /*** SENTINEL ***/
229 /* File scope variables */
231 /* context dependent list of specials for parser to recognize,
232 * required for us to be able distinguish between 'mon' as 'month'
233 * and 'mon' as 'monday'
235 static const struct SpecialToken *Specials;
237 static const char **scp; /* scanner - pointer at arglist */
238 static char scc; /* scanner - count of remaining arguments */
239 static const char *sct; /* scanner - next char pointer in current argument */
240 static int need; /* scanner - need to advance to next argument */
242 static char *sc_token = NULL; /* scanner - token buffer */
243 static size_t sc_len; /* scanner - length of token buffer */
244 static int sc_tokid; /* scanner - token id */
246 /* Local functions */
247 static void EnsureMemFree(
250 static void EnsureMemFree(
260 * A hack to compensate for the lack of the C++ exceptions
262 * Every function func that might generate parsing "exception"
263 * should return TIME_OK (aka NULL) or pointer to the error message,
264 * and should be called like this: try(func(args));
266 * if the try is not successful it will reset the token pointer ...
268 * [NOTE: when try(...) is used as the only statement in the "if-true"
269 * part of the if statement that also has an "else" part it should be
270 * either enclosed in the curly braces (despite the fact that it looks
271 * like a single statement) or NOT followed by the ";"]
283 * The panic() function was used in the original code to die, we redefine
284 * it as macro to start the chain of ascending returns that in conjunction
285 * with the try(b) above will simulate a sort of "exception handling"
293 * ve() and e() are used to set the return error,
294 * the most appropriate use for these is inside panic(...)
296 #define MAX_ERR_MSG_LEN 1024
297 static char errmsg[MAX_ERR_MSG_LEN];
303 #ifdef HAVE_VSNPRINTF
304 vsnprintf(errmsg, MAX_ERR_MSG_LEN, fmt, ap);
306 vsprintf(errmsg, fmt, ap);
325 /* Compare S1 and S2, ignoring case, returning less than, equal to or
326 greater than zero if S1 is lexicographically less than,
327 equal to or greater than S2. -- copied from GNU libc*/
328 static int mystrcasecmp(
332 const unsigned char *p1 = (const unsigned char *) s1;
333 const unsigned char *p2 = (const unsigned char *) s2;
334 unsigned char c1, c2;
351 * parse a token, checking if it's something special to us
353 static int parse_token(
358 for (i = 0; Specials[i].name != NULL; i++)
359 if (mystrcasecmp(Specials[i].name, arg) == 0)
360 return sc_tokid = Specials[i].value;
362 /* not special - must be some random id */
363 return sc_tokid = ID;
369 * init_scanner() sets up the scanner to eat arguments
371 static char *init_scanner(
380 sc_len += strlen(*argv++);
382 sc_token = (char *) malloc(sc_len * sizeof(char));
383 if (sc_token == NULL)
384 return "Failed to allocate memory";
389 * token() fetches a token from the input stream
397 memset(sc_token, '\0', sc_len);
401 /* if we need to read another argument, walk along the argument list;
402 * when we fall off the arglist, we'll just return EOF forever
412 /* eat whitespace now - if we walk off the end of the argument,
413 * we'll continue, which puts us up at the top of the while loop
414 * to fetch the next argument in
416 while (isspace((unsigned char) *sct) || *sct == '_' || *sct == ',')
423 /* preserve the first character of the new token
425 sc_token[0] = *sct++;
427 /* then see what it is
429 if (isdigit((unsigned char) (sc_token[0]))) {
430 while (isdigit((unsigned char) (*sct)))
431 sc_token[++idx] = *sct++;
432 sc_token[++idx] = '\0';
433 return sc_tokid = NUMBER;
434 } else if (isalpha((unsigned char) (sc_token[0]))) {
435 while (isalpha((unsigned char) (*sct)))
436 sc_token[++idx] = *sct++;
437 sc_token[++idx] = '\0';
438 return parse_token(sc_token);
440 switch (sc_token[0]) {
442 return sc_tokid = COLON;
444 return sc_tokid = DOT;
446 return sc_tokid = PLUS;
448 return sc_tokid = MINUS;
450 return sc_tokid = SLASH;
452 /*OK, we did not make it ... */
454 return sc_tokid = EOF;
461 * expect2() gets a token and complains if it's not the token we want
463 static char *expect2(
470 va_start(ap, complain_fmt);
471 if (token() != desired) {
472 panic(ve(complain_fmt, ap));
481 * plus_minus() is used to parse a single NUMBER TIME-UNIT pair
482 * for the OFFSET-SPEC.
483 * It also applies those m-guessing heuristics.
485 static char *plus_minus(
486 rrd_time_value_t * ptv,
489 static int op = PLUS;
490 static int prev_multiplier = -1;
496 (NUMBER, "There should be number after '%c'",
497 op == PLUS ? '+' : '-'));
498 prev_multiplier = -1; /* reset months-minutes guessing mechanics */
500 /* if doop is < 0 then we repeat the previous op
501 * with the prefetched number */
503 delta = atoi(sc_token);
505 if (token() == MONTHS_MINUTES) {
506 /* hard job to guess what does that -5m means: -5mon or -5min? */
507 switch (prev_multiplier) {
522 if (delta < 6) /* it may be some other value but in the context
523 * of RRD who needs less than 6 min deltas? */
529 prev_multiplier = sc_tokid;
532 ptv->tm. tm_year += (
533 op == PLUS) ? delta : -delta;
538 op == PLUS) ? delta : -delta;
545 ptv->tm. tm_mday += (
546 op == PLUS) ? delta : -delta;
550 ptv->offset += (op == PLUS) ? delta * 60 * 60 : -delta * 60 * 60;
553 ptv->offset += (op == PLUS) ? delta * 60 : -delta * 60;
556 ptv->offset += (op == PLUS) ? delta : -delta;
558 default: /*default unit is seconds */
559 ptv->offset += (op == PLUS) ? delta : -delta;
562 panic(e("well-known time unit expected after %d", delta));
564 return TIME_OK; /* to make compiler happy :) */
569 * tod() computes the time of day (TIME-OF-DAY-SPEC)
572 rrd_time_value_t * ptv)
574 int hour, minute = 0;
577 /* save token status in case we must abort */
579 const char *sct_sv = sct;
580 int sc_tokid_sv = sc_tokid;
582 tlen = strlen(sc_token);
584 /* first pick out the time of day - we assume a HH (COLON|DOT) MM time
590 hour = atoi(sc_token);
593 if (sc_tokid == SLASH || sc_tokid == DOT) {
594 /* guess we are looking at a date */
597 sc_tokid = sc_tokid_sv;
598 sprintf(sc_token, "%d", hour);
601 if (sc_tokid == COLON) {
603 "Parsing HH:MM syntax, expecting MM as number, got none"));
604 minute = atoi(sc_token);
606 panic(e("parsing HH:MM syntax, got MM = %d (>59!)", minute));
611 /* check if an AM or PM specifier was given
613 if (sc_tokid == AM || sc_tokid == PM) {
615 panic(e("there cannot be more than 12 AM or PM hours"));
617 if (sc_tokid == PM) {
618 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */
621 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */
625 } else if (hour > 23) {
626 /* guess it was not a time then ... */
629 sc_tokid = sc_tokid_sv;
630 sprintf(sc_token, "%d", hour);
633 ptv->tm. tm_hour = hour;
634 ptv->tm. tm_min = minute;
637 if (ptv->tm.tm_hour == 24) {
638 ptv->tm. tm_hour = 0;
646 * assign_date() assigns a date, adjusting year as appropriate
648 static char *assign_date(
649 rrd_time_value_t * ptv,
658 panic(e("invalid year %d (should be either 00-99 or >1900)",
661 } else if (year >= 0 && year < 38) {
662 year += 100; /* Allow year 2000-2037 to be specified as */
664 /* 00-37 until the problem of 2038 year will */
665 /* arise for unices with 32-bit time_t :) */
667 panic(e("won't handle dates before epoch (01/01/1970), sorry"));
670 ptv->tm. tm_mday = mday;
671 ptv->tm. tm_mon = mon;
672 ptv->tm. tm_year = year;
679 * day() picks apart DAY-SPEC-[12]
682 rrd_time_value_t * ptv)
684 /* using time_t seems to help portability with 64bit oses */
685 time_t mday = 0, wday, mon, year = ptv->tm.tm_year;
693 case TODAY: /* force ourselves to stay in today - no further processing */
714 /* do month mday [year]
716 mon = (sc_tokid - JAN);
717 try(expect2(NUMBER, "the day of the month should follow month name"));
718 mday = atol(sc_token);
719 if (token() == NUMBER) {
720 year = atol(sc_token);
723 year = ptv->tm.tm_year;
725 try(assign_date(ptv, mday, mon, year));
735 /* do a particular day of the week
737 wday = (sc_tokid - SUN);
738 ptv->tm. tm_mday += (
739 wday - ptv->tm.tm_wday);
744 mday = ptv->tm.tm_mday;
745 mday += (wday - ptv->tm.tm_wday);
746 ptv->tm.tm_wday = wday;
748 try(assign_date(ptv, mday, ptv->tm.tm_mon, ptv->tm.tm_year));
753 /* get numeric <sec since 1970>, MM/DD/[YY]YY, or DD.MM.[YY]YY
755 tlen = strlen(sc_token);
756 mon = atol(sc_token);
757 if (mon > 10 * 365 * 24 * 60 * 60) {
758 ptv->tm = *localtime(&mon);
764 if (mon > 19700101 && mon < 24000101) { /*works between 1900 and 2400 */
765 char cmon[3], cmday[3], cyear[5];
767 strncpy(cyear, sc_token, 4);
770 strncpy(cmon, &(sc_token[4]), 2);
773 strncpy(cmday, &(sc_token[6]), 2);
780 if (mon <= 31 && (sc_tokid == SLASH || sc_tokid == DOT)) {
784 try(expect2(NUMBER, "there should be %s number after '%c'",
785 sep == DOT ? "month" : "day",
786 sep == DOT ? '.' : '/'));
787 mday = atol(sc_token);
788 if (token() == sep) {
790 (NUMBER, "there should be year number after '%c'",
791 sep == DOT ? '.' : '/'));
792 year = atol(sc_token);
796 /* flip months and days for European timing
808 if (mon < 0 || mon > 11) {
809 panic(e("did you really mean month %d?", mon + 1));
811 if (mday < 1 || mday > 31) {
812 panic(e("I'm afraid that %d is not a valid day of the month",
815 try(assign_date(ptv, mday, mon, year));
822 /* Global functions */
826 * rrd_parsetime() is the external interface that takes tspec, parses
827 * it and puts the result in the rrd_time_value structure *ptv.
828 * It can return either absolute times (these are ensured to be
829 * correct) or relative time references that are expected to be
830 * added to some absolute time value and then normalized by
831 * mktime() The return value is either TIME_OK (aka NULL) or
832 * the pointer to the error message in the case of problems
836 rrd_time_value_t * ptv)
838 time_t now = time(NULL);
841 /* this MUST be initialized to zero for midnight/noon/teatime */
843 Specials = VariousWords; /* initialize special words context */
845 try(init_scanner(1, &tspec));
847 /* establish the default time reference */
848 ptv->type = ABSOLUTE_TIME;
850 ptv->tm = *localtime(&now);
851 ptv->tm. tm_isdst = -1; /* mk time can figure dst by default ... */
857 break; /* jump to OFFSET-SPEC part */
860 ptv->type = RELATIVE_TO_START_TIME;
863 ptv->type = RELATIVE_TO_END_TIME;
867 ptv->tm. tm_hour = 0;
868 ptv->tm. tm_mday = 0;
870 ptv->tm. tm_year = 0;
875 int time_reference = sc_tokid;
878 if (sc_tokid == PLUS || sc_tokid == MINUS)
880 if (time_reference != NOW) {
881 panic(e("'start' or 'end' MUST be followed by +|- offset"));
882 } else if (sc_tokid != EOF) {
883 panic(e("if 'now' is followed by a token it must be +|- offset"));
888 /* Only absolute time specifications below */
891 long hour_sv = ptv->tm.tm_hour;
892 long year_sv = ptv->tm.tm_year;
894 ptv->tm. tm_hour = 30;
895 ptv->tm. tm_year = 30000;
899 if (ptv->tm.tm_hour == 30 && ptv->tm.tm_year != 30000) {
902 if (ptv->tm.tm_hour == 30) {
903 ptv->tm. tm_hour = hour_sv;
905 if (ptv->tm.tm_year == 30000) {
906 ptv->tm. tm_year = year_sv;
910 /* fix month parsing */
924 if (sc_tokid != NUMBER)
929 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialized
930 * hr to zero up above, then fall into this case in such a
931 * way so we add +12 +4 hours to it for teatime, +12 hours
932 * to it for noon, and nothing at all for midnight, then
933 * set our rettime to that hour before leaping into the
943 /* if (ptv->tm.tm_hour >= hr) {
946 } *//* shifting does not makes sense here ... noon is noon */
947 ptv->tm. tm_hour = hr;
955 panic(e("unparsable time: %s%s", sc_token, sct));
957 } /* ugly case statement */
960 * the OFFSET-SPEC part
962 * (NOTE, the sc_tokid was prefetched for us by the previous code)
964 if (sc_tokid == PLUS || sc_tokid == MINUS) {
965 Specials = TimeMultipliers; /* switch special words context */
966 while (sc_tokid == PLUS || sc_tokid == MINUS || sc_tokid == NUMBER) {
967 if (sc_tokid == NUMBER) {
968 try(plus_minus(ptv, PREVIOUS_OP));
970 try(plus_minus(ptv, sc_tokid));
971 token(); /* We will get EOF eventually but that's OK, since
972 token() will return us as many EOFs as needed */
976 /* now we should be at EOF */
977 if (sc_tokid != EOF) {
978 panic(e("unparsable trailing text: '...%s%s'", sc_token, sct));
981 if (ptv->type == ABSOLUTE_TIME)
982 if (mktime(&ptv->tm) == -1) { /* normalize & check */
983 /* can happen for "nonexistent" times, e.g. around 3am */
984 /* when winter -> summer time correction eats a hour */
985 panic(e("the specified time is incorrect (out of range?)"));
989 } /* rrd_parsetime */
992 int rrd_proc_start_end(
993 rrd_time_value_t * start_tv,
994 rrd_time_value_t * end_tv,
998 if (start_tv->type == RELATIVE_TO_END_TIME && /* same as the line above */
999 end_tv->type == RELATIVE_TO_START_TIME) {
1000 rrd_set_error("the start and end times cannot be specified "
1001 "relative to each other");
1005 if (start_tv->type == RELATIVE_TO_START_TIME) {
1007 ("the start time cannot be specified relative to itself");
1011 if (end_tv->type == RELATIVE_TO_END_TIME) {
1012 rrd_set_error("the end time cannot be specified relative to itself");
1016 if (start_tv->type == RELATIVE_TO_END_TIME) {
1019 *end = mktime(&(end_tv->tm)) + end_tv->offset;
1020 tmtmp = *localtime(end); /* reinit end including offset */
1021 tmtmp.tm_mday += start_tv->tm.tm_mday;
1022 tmtmp.tm_mon += start_tv->tm.tm_mon;
1023 tmtmp.tm_year += start_tv->tm.tm_year;
1025 *start = mktime(&tmtmp) + start_tv->offset;
1027 *start = mktime(&(start_tv->tm)) + start_tv->offset;
1029 if (end_tv->type == RELATIVE_TO_START_TIME) {
1032 *start = mktime(&(start_tv->tm)) + start_tv->offset;
1033 tmtmp = *localtime(start);
1034 tmtmp.tm_mday += end_tv->tm.tm_mday;
1035 tmtmp.tm_mon += end_tv->tm.tm_mon;
1036 tmtmp.tm_year += end_tv->tm.tm_year;
1038 *end = mktime(&tmtmp) + end_tv->offset;
1040 *end = mktime(&(end_tv->tm)) + end_tv->offset;
1043 } /* rrd_proc_start_end */