/usr.bin/at/parsetime.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 670 lines · 439 code · 90 blank · 141 comment · 113 complexity · 4fd6be20a16b061b2016ee2d014049c2 MD5 · raw file
- /*
- * 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/
- */
- #include <sys/cdefs.h>
- __FBSDID("$FreeBSD$");
- /* System Headers */
- #include <sys/types.h>
- #include <ctype.h>
- #include <err.h>
- #include <errno.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <time.h>
- #include <unistd.h>
- #ifndef __FreeBSD__
- #include <getopt.h>
- #endif
- /* Local headers */
- #include "at.h"
- #include "panic.h"
- #include "parsetime.h"
- /* Structures and unions */
- enum { /* symbols */
- MIDNIGHT, NOON, TEATIME,
- PM, AM, TOMORROW, TODAY, NOW,
- MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS,
- NUMBER, PLUS, MINUS, DOT, SLASH, ID, JUNK,
- JAN, FEB, MAR, APR, MAY, JUN,
- JUL, AUG, SEP, OCT, NOV, DEC,
- SUN, MON, TUE, WED, THU, FRI, SAT
- };
- /* parse translation table - table driven parsers can be your FRIEND!
- */
- static const struct {
- const char *name; /* token name */
- int value; /* token id */
- int plural; /* is this plural? */
- } Specials[] = {
- { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */
- { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */
- { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */
- { "am", AM,0 }, /* morning times for 0-12 clock */
- { "pm", PM,0 }, /* evening times for 0-12 clock */
- { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */
- { "today", TODAY, 0 }, /* execute today - don't advance time */
- { "now", NOW,0 }, /* opt prefix for PLUS */
- { "minute", MINUTES,0 }, /* minutes multiplier */
- { "minutes", MINUTES,1 }, /* (pluralized) */
- { "hour", HOURS,0 }, /* hours ... */
- { "hours", HOURS,1 }, /* (pluralized) */
- { "day", DAYS,0 }, /* days ... */
- { "days", DAYS,1 }, /* (pluralized) */
- { "week", WEEKS,0 }, /* week ... */
- { "weeks", WEEKS,1 }, /* (pluralized) */
- { "month", MONTHS,0 }, /* month ... */
- { "months", MONTHS,1 }, /* (pluralized) */
- { "year", YEARS,0 }, /* year ... */
- { "years", YEARS,1 }, /* (pluralized) */
- { "jan", JAN,0 },
- { "feb", FEB,0 },
- { "mar", MAR,0 },
- { "apr", APR,0 },
- { "may", MAY,0 },
- { "jun", JUN,0 },
- { "jul", JUL,0 },
- { "aug", AUG,0 },
- { "sep", SEP,0 },
- { "oct", OCT,0 },
- { "nov", NOV,0 },
- { "dec", DEC,0 },
- { "january", JAN,0 },
- { "february", FEB,0 },
- { "march", MAR,0 },
- { "april", APR,0 },
- { "may", MAY,0 },
- { "june", JUN,0 },
- { "july", JUL,0 },
- { "august", AUG,0 },
- { "september", SEP,0 },
- { "october", OCT,0 },
- { "november", NOV,0 },
- { "december", DEC,0 },
- { "sunday", SUN, 0 },
- { "sun", SUN, 0 },
- { "monday", MON, 0 },
- { "mon", MON, 0 },
- { "tuesday", TUE, 0 },
- { "tue", TUE, 0 },
- { "wednesday", WED, 0 },
- { "wed", WED, 0 },
- { "thursday", THU, 0 },
- { "thu", THU, 0 },
- { "friday", FRI, 0 },
- { "fri", FRI, 0 },
- { "saturday", SAT, 0 },
- { "sat", SAT, 0 },
- } ;
- /* File scope variables */
- static char **scp; /* scanner - pointer at arglist */
- static char scc; /* scanner - count of remaining arguments */
- static char *sct; /* scanner - next char pointer in current argument */
- static int need; /* scanner - need to advance to next argument */
- static char *sc_token; /* scanner - token buffer */
- static size_t sc_len; /* scanner - length of token buffer */
- static int sc_tokid; /* scanner - token id */
- static int sc_tokplur; /* scanner - is token plural? */
- /* Local functions */
- /*
- * parse a token, checking if it's something special to us
- */
- static int
- parse_token(char *arg)
- {
- size_t i;
- for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++)
- if (strcasecmp(Specials[i].name, arg) == 0) {
- sc_tokplur = Specials[i].plural;
- return sc_tokid = Specials[i].value;
- }
- /* not special - must be some random id */
- return ID;
- } /* parse_token */
- /*
- * init_scanner() sets up the scanner to eat arguments
- */
- static void
- init_scanner(int argc, char **argv)
- {
- scp = argv;
- scc = argc;
- need = 1;
- sc_len = 1;
- while (argc-- > 0)
- sc_len += strlen(*argv++);
- if ((sc_token = malloc(sc_len)) == NULL)
- errx(EXIT_FAILURE, "virtual memory exhausted");
- } /* init_scanner */
- /*
- * token() fetches a token from the input stream
- */
- static int
- token(void)
- {
- int idx;
- while (1) {
- memset(sc_token, 0, sc_len);
- sc_tokid = EOF;
- sc_tokplur = 0;
- idx = 0;
- /* if we need to read another argument, walk along the argument list;
- * when we fall off the arglist, we'll just return EOF forever
- */
- if (need) {
- if (scc < 1)
- return sc_tokid;
- sct = *scp;
- scp++;
- scc--;
- need = 0;
- }
- /* 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(*sct))
- ++sct;
- if (!*sct) {
- need = 1;
- continue;
- }
- /* preserve the first character of the new token
- */
- sc_token[0] = *sct++;
- /* then see what it is
- */
- if (isdigit(sc_token[0])) {
- while (isdigit(*sct))
- sc_token[++idx] = *sct++;
- sc_token[++idx] = 0;
- return sc_tokid = NUMBER;
- }
- else if (isalpha(sc_token[0])) {
- while (isalpha(*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 = MINUS;
- else if (sc_token[0] == '/')
- return sc_tokid = SLASH;
- else
- return sc_tokid = JUNK;
- } /* while (1) */
- } /* token */
- /*
- * plonk() gives an appropriate error message if a token is incorrect
- */
- static void
- plonk(int tok)
- {
- panic((tok == EOF) ? "incomplete time"
- : "garbled time");
- } /* plonk */
- /*
- * expect() gets a token and dies most horribly if it's not the token we want
- */
- static void
- expect(int desired)
- {
- if (token() != desired)
- plonk(sc_tokid); /* and we die here... */
- } /* expect */
- /*
- * plus_or_minus() holds functionality common to plus() and minus()
- */
- static void
- plus_or_minus(struct tm *tm, int delay)
- {
- int expectplur;
- expectplur = (delay != 1 && delay != -1) ? 1 : 0;
- switch (token()) {
- case YEARS:
- tm->tm_year += delay;
- break;
- case MONTHS:
- tm->tm_mon += delay;
- break;
- case WEEKS:
- delay *= 7;
- 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) < 0)
- plonk(sc_tokid);
- } /* plus_or_minus */
- /*
- * plus() parses a now + time
- *
- * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS]
- *
- */
- static void
- plus(struct tm *tm)
- {
- int delay;
- expect(NUMBER);
- delay = atoi(sc_token);
- plus_or_minus(tm, delay);
- } /* plus */
- /*
- * minus() is like plus but can not be used with NOW
- */
- static void
- minus(struct tm *tm)
- {
- int delay;
- expect(NUMBER);
- delay = -atoi(sc_token);
- plus_or_minus(tm, delay);
- } /* minus */
- /*
- * tod() computes the time of day
- * [NUMBER [DOT NUMBER] [AM|PM]]
- */
- static void
- tod(struct tm *tm)
- {
- int hour, minute = 0;
- int tlen;
- hour = atoi(sc_token);
- tlen = strlen(sc_token);
- /* 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);
- if (minute > 59)
- panic("garbled time");
- token();
- }
- else if (tlen == 4) {
- minute = hour%100;
- if (minute > 59)
- panic("garbled time");
- hour = hour/100;
- }
- /* 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;
- }
- 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 == EOF || sc_tokid == PLUS || sc_tokid == MINUS) &&
- tm->tm_hour > hour) {
- tm->tm_mday++;
- tm->tm_wday++;
- }
- tm->tm_hour = hour;
- tm->tm_min = minute;
- if (tm->tm_hour == 24) {
- tm->tm_hour = 0;
- tm->tm_mday++;
- }
- } /* tod */
- /*
- * assign_date() assigns a date, wrapping to next year if needed
- */
- static void
- assign_date(struct tm *tm, long mday, long mon, long year)
- {
- /*
- * Convert year into tm_year format (year - 1900).
- * We may be given the year in 2 digit, 4 digit, or tm_year format.
- */
- if (year != -1) {
- if (year >= 1900)
- year -= 1900; /* convert from 4 digit year */
- else if (year < 100) {
- /* convert from 2 digit year */
- struct tm *lt;
- time_t now;
- time(&now);
- lt = localtime(&now);
- /* Convert to tm_year assuming current century */
- year += (lt->tm_year / 100) * 100;
- if (year == lt->tm_year - 1) year++;
- else if (year < lt->tm_year)
- year += 100; /* must be in next century */
- }
- }
- if (year < 0 &&
- (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday)))
- year = tm->tm_year + 1;
- tm->tm_mday = mday;
- tm->tm_mon = mon;
- if (year >= 0)
- tm->tm_year = year;
- } /* assign_date */
- /*
- * 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)
- {
- long year= (-1);
- long mday = 0, wday, mon;
- int tlen;
- switch (sc_tokid) {
- case PLUS:
- plus(tm);
- break;
- case MINUS:
- minus(tm);
- break;
- case TOMORROW:
- /* do something tomorrow */
- tm->tm_mday ++;
- tm->tm_wday ++;
- case TODAY: /* force ourselves to stay in today - no further processing */
- 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 = atol(sc_token);
- if (token() == NUMBER) {
- year = atol(sc_token);
- 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);
- tm->tm_wday = wday;
- assign_date(tm, mday, tm->tm_mon, tm->tm_year);
- break;
- case NUMBER:
- /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy
- */
- tlen = strlen(sc_token);
- mon = atol(sc_token);
- token();
- if (sc_tokid == SLASH || sc_tokid == DOT) {
- int sep;
- sep = sc_tokid;
- expect(NUMBER);
- mday = atol(sc_token);
- if (token() == sep) {
- expect(NUMBER);
- year = atol(sc_token);
- token();
- }
- /* flip months and days for European timing
- */
- if (sep == DOT) {
- int x = mday;
- mday = mon;
- mon = x;
- }
- }
- else if (tlen == 6 || tlen == 8) {
- if (tlen == 8) {
- year = (mon % 10000) - 1900;
- mon /= 10000;
- }
- else {
- year = mon % 100;
- mon /= 100;
- }
- mday = mon % 100;
- mon /= 100;
- }
- else
- panic("garbled time");
- mon--;
- if (mon < 0 || mon > 11 || mday < 1 || mday > 31)
- panic("garbled time");
- assign_date(tm, mday, mon, year);
- break;
- } /* case */
- } /* month */
- /* Global functions */
- 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 */
- nowtimer = time(NULL);
- nowtime = *localtime(&nowtimer);
- runtime = nowtime;
- runtime.tm_sec = 0;
- runtime.tm_isdst = 0;
- if (argc <= optind)
- usage();
- init_scanner(argc-optind, argv+optind);
- switch (token()) {
- case NOW:
- if (scc < 1) {
- return nowtimer;
- }
- /* now is optional prefix for PLUS tree */
- expect(PLUS);
- case PLUS:
- plus(&runtime);
- break;
- /* MINUS is different from PLUS in that NOW is not
- * an optional prefix for it
- */
- case MINUS:
- minus(&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;
- case NOON:
- hr += 12;
- case MIDNIGHT:
- if (runtime.tm_hour >= hr) {
- runtime.tm_mday++;
- runtime.tm_wday++;
- }
- runtime.tm_hour = hr;
- runtime.tm_min = 0;
- token();
- /* FALLTHROUGH to month setting */
- default:
- month(&runtime);
- break;
- } /* ugly case statement */
- expect(EOF);
- /* convert back to time_t
- */
- runtime.tm_isdst = -1;
- runtimer = mktime(&runtime);
- if (runtimer < 0)
- panic("garbled time");
- if (nowtimer > runtimer)
- panic("trying to travel back in time");
- return runtimer;
- } /* parsetime */