/*
* parsetime.c - parse time for at(1)
* Copyright (C) 1993, 1994 Thomas Koenig
*
* modifications for english-language times
* Copyright (C) 1993 David Parsons
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author(s) may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* at [NOW] PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS
* /NUMBER [DOT NUMBER] [AM|PM]\ /[MONTH NUMBER [NUMBER]] \
* |NOON | |[TOMORROW] |
* |MIDNIGHT | |[DAY OF WEEK] |
* \TEATIME / |NUMBER [SLASH NUMBER [SLASH NUMBER]]|
* \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/
*/
/*
* if we need to read another argument, walk along the
* argument list; when we fall off the arglist, we'll
* just return TOKEOF forever
*/
if (need) {
if (scc < 1)
return sc_tokid;
sct = *scp;
scp++;
scc--;
need = false;
}
/*
* eat whitespace now - if we walk off the end of the argument,
* we'll continue, which puts us up at the top of the while loop
* to fetch the next argument in
*/
while (isspace((unsigned char)*sct))
++sct;
if (!*sct) {
need = true;
continue;
}
/*
* preserve the first character of the new token
*/
sc_token[0] = *sct++;
/*
* then see what it is
*/
if (isdigit((unsigned char)sc_token[0])) {
while (isdigit((unsigned char)*sct))
sc_token[++idx] = *sct++;
sc_token[++idx] = 0;
return sc_tokid = NUMBER;
} else if (isalpha((unsigned char)sc_token[0])) {
while (isalpha((unsigned char)*sct))
sc_token[++idx] = *sct++;
sc_token[++idx] = 0;
return parse_token(sc_token);
}
else if (sc_token[0] == ':' || sc_token[0] == '.')
return sc_tokid = DOT;
else if (sc_token[0] == '+')
return sc_tokid = PLUS;
else if (sc_token[0] == '/')
return sc_tokid = SLASH;
else
return sc_tokid = JUNK;
}
}
/*
* plonk() gives an appropriate error message if a token is incorrect
*/
__dead
static void
plonk(tokid_t tok)
{
/*
* expect() gets a token and dies most horribly if it's not the token we want
*/
static void
expect(tokid_t desired)
{
if (token() != desired)
plonk(sc_tokid); /* and we die here... */
}
/*
* plus() parses a now + time
*
* at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS]
*
*/
static void
plus(struct tm *tm)
{
int delay;
int expectplur;
expect(NUMBER);
delay = atoi(sc_token);
expectplur = delay != 1;
switch (token()) {
case YEARS:
tm->tm_year += delay;
break;
case MONTHS:
tm->tm_mon += delay;
break;
case WEEKS:
delay *= 7;
/*FALLTHROUGH*/
case DAYS:
tm->tm_mday += delay;
break;
case HOURS:
tm->tm_hour += delay;
break;
case MINUTES:
tm->tm_min += delay;
break;
default:
plonk(sc_tokid);
break;
}
if (expectplur != sc_tokplur)
warnx("pluralization is wrong");
tm->tm_isdst = -1;
if (mktime(tm) == -1)
plonk(sc_tokid);
}
/*
* tod() computes the time of day
* [NUMBER [DOT NUMBER] [AM|PM]]
*/
static void
tod(struct tm *tm)
{
int hour, minute;
size_t tlen;
/*
* first pick out the time of day - if it's 4 digits, we assume
* a HHMM time, otherwise it's HH DOT MM time
*/
if (token() == DOT) {
expect(NUMBER);
minute = atoi(sc_token);
(void)token();
} else if (tlen == 4) {
minute = hour % 100;
hour = hour / 100;
}
if (minute > 59)
panic("garbled time");
/*
* check if an AM or PM specifier was given
*/
if (sc_tokid == AM || sc_tokid == PM) {
if (hour > 12)
panic("garbled time");
if (sc_tokid == PM) {
if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */
hour += 12;
} else {
if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */
hour = 0;
}
(void)token();
} else if (hour > 23)
panic("garbled time");
/*
* if we specify an absolute time, we don't want to bump the day even
* if we've gone past that time - but if we're specifying a time plus
* a relative offset, it's okay to bump things
*/
if ((sc_tokid == TOKEOF || sc_tokid == PLUS) && (tm->tm_hour > hour ||
(tm->tm_hour == hour && tm->tm_min > minute))) {
tm->tm_mday++;
tm->tm_wday++;
}
tm->tm_hour = hour;
tm->tm_min = minute;
}
/*
* assign_date() assigns a date, wrapping to next year if needed.
* Accept years in 4-digit, 2-digit, or current year (-1).
*/
static void
assign_date(struct tm *tm, int mday, int mon, int year)
{
if (year > 99) { /* four digit year */
if (year >= TM_YEAR_BASE)
tm->tm_year = year - TM_YEAR_BASE;
else
panic("garbled time");
}
else if (year >= 0) { /* two digit year */
tm->tm_year = conv_2dig_year(year) - TM_YEAR_BASE;
}
else if (year == -1) { /* year not given (use default in tm) */
/* allow for 1 year range from current date */
if (tm->tm_mon > mon ||
(tm->tm_mon == mon && tm->tm_mday > mday))
tm->tm_year++;
}
else
panic("invalid year");
tm->tm_mday = mday;
tm->tm_mon = mon;
}
/*
* month() picks apart a month specification
*
* /[<month> NUMBER [NUMBER]] \
* |[TOMORROW] |
* |[DAY OF WEEK] |
* |NUMBER [SLASH NUMBER [SLASH NUMBER]]|
* \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/
*/
static void
month(struct tm *tm)
{
int year;
int mday, wday, mon;
size_t tlen;
year = -1;
mday = 0;
switch (sc_tokid) {
case PLUS:
plus(tm);
break;
case TOMORROW:
/* do something tomorrow */
tm->tm_mday++;
tm->tm_wday++;
/*FALLTHROUGH*/
case TODAY:
/* force ourselves to stay in today - no further processing */
(void)token();
break;
case JAN: case FEB: case MAR: case APR: case MAY: case JUN:
case JUL: case AUG: case SEP: case OCT: case NOV: case DEC:
/*
* do month mday [year]
*/
mon = sc_tokid - JAN;
expect(NUMBER);
mday = atoi(sc_token);
if (token() == NUMBER) {
year = atoi(sc_token);
(void)token();
}
assign_date(tm, mday, mon, year);
break;
case SUN: case MON: case TUE:
case WED: case THU: case FRI:
case SAT:
/* do a particular day of the week */
wday = sc_tokid - SUN;
mday = tm->tm_mday;
/* if this day is < today, then roll to next week */
if (wday < tm->tm_wday)
mday += 7 - (tm->tm_wday - wday);
else
mday += (wday - tm->tm_wday);
time_t
parsetime(int argc, char **argv)
{
/*
* Do the argument parsing, die if necessary, and return the
* time the job should be run.
*/
time_t nowtimer, runtimer;
struct tm nowtime, runtime;
int hr = 0; /* this MUST be initialized to zero for
midnight/noon/teatime */
switch (token()) {
case NOW:
if (scc < 1)
return nowtimer;
/* now is optional prefix for PLUS tree */
expect(PLUS);
/*FALLTHROUGH*/
case PLUS:
plus(&runtime);
break;
case NUMBER:
tod(&runtime);
month(&runtime);
break;
/*
* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised
* hr to zero up above, then fall into this case in such a
* way so we add +12 +4 hours to it for teatime, +12 hours
* to it for noon, and nothing at all for midnight, then
* set our runtime to that hour before leaping into the
* month scanner
*/
case TEATIME:
hr += 4;
/*FALLTHROUGH*/
case NOON:
hr += 12;
/*FALLTHROUGH*/
case MIDNIGHT:
if (runtime.tm_hour >= hr) {
runtime.tm_mday++;
runtime.tm_wday++;
}
runtime.tm_hour = hr;
runtime.tm_min = 0;
(void)token();
/*FALLTHROUGH*/ /* fall through to month setting */
default:
month(&runtime);
break;
}
expect(TOKEOF);
/*
* adjust for daylight savings time
*/
runtime.tm_isdst = -1;
runtimer = mktime(&runtime);
if (runtimer == (time_t)-1)
panic("Invalid time");
if (nowtimer > runtimer)
panic("Trying to travel back in time");
