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-rw-r--r--usr.bin/at/parsetime.c591
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+/*
+ * parsetime.c - parse time for at(1)
+ * Copyright (C) 1993 Thomas Koenig
+ *
+ * modifications for english-language times
+ * Copyright (C) 1993 David Parsons
+ * All rights reserved.
+ *
+ * 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 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 | |NUMBER [SLASH NUMBER [SLASH NUMBER]]|
+ * \TEATIME / \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/
+ */
+
+/* System Headers */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <ctype.h>
+
+/* Local headers */
+
+#include "at.h"
+#include "panic.h"
+
+
+/* Structures and unions */
+
+enum { /* symbols */
+ MIDNIGHT, NOON, TEATIME,
+ PM, AM, TOMORROW, TODAY, NOW,
+ MINUTES, HOURS, DAYS, WEEKS,
+ NUMBER, PLUS, DOT, SLASH, ID, JUNK,
+ JAN, FEB, MAR, APR, MAY, JUN,
+ JUL, AUG, SEP, OCT, NOV, DEC
+};
+
+/*
+ * parse translation table - table driven parsers can be your FRIEND!
+ */
+struct {
+ char *name; /* token name */
+ int value; /* token id */
+} Specials[] = {
+ { "midnight", MIDNIGHT }, /* 00:00:00 of today or tomorrow */
+ { "noon", NOON }, /* 12:00:00 of today or tomorrow */
+ { "teatime", TEATIME }, /* 16:00:00 of today or tomorrow */
+ { "am", AM }, /* morning times for 0-12 clock */
+ { "pm", PM }, /* evening times for 0-12 clock */
+ { "tomorrow", TOMORROW }, /* execute 24 hours from time */
+ { "today", TODAY }, /* execute today - don't advance time */
+ { "now", NOW }, /* opt prefix for PLUS */
+
+ { "minute", MINUTES }, /* minutes multiplier */
+ { "min", MINUTES },
+ { "m", MINUTES },
+ { "minutes", MINUTES }, /* (pluralized) */
+ { "hour", HOURS }, /* hours ... */
+ { "hr", HOURS }, /* abbreviated */
+ { "h", HOURS },
+ { "hours", HOURS }, /* (pluralized) */
+ { "day", DAYS }, /* days ... */
+ { "d", DAYS },
+ { "days", DAYS }, /* (pluralized) */
+ { "week", WEEKS }, /* week ... */
+ { "w", WEEKS },
+ { "weeks", WEEKS }, /* (pluralized) */
+ { "jan", JAN },
+ { "feb", FEB },
+ { "mar", MAR },
+ { "apr", APR },
+ { "may", MAY },
+ { "jun", JUN },
+ { "jul", JUL },
+ { "aug", AUG },
+ { "sep", SEP },
+ { "oct", OCT },
+ { "nov", NOV },
+ { "dec", DEC }
+} ;
+
+/* 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 - lenght of token buffer */
+static int sc_tokid; /* scanner - token id */
+
+static char rcsid[] = "$Id: parsetime.c,v 1.1 1993/12/05 11:37:05 cgd Exp $";
+
+/* Local functions */
+
+/*
+ * parse a token, checking if it's something special to us
+ */
+static int
+parse_token(arg)
+ char *arg;
+{
+ int i;
+
+ for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++)
+ if (strcasecmp(Specials[i].name, arg) == 0) {
+ 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(argc, argv)
+ int argc;
+ char **argv;
+{
+ scp = argv;
+ scc = argc;
+ need = 1;
+ sc_len = 1;
+ while (--argc > 0)
+ sc_len += strlen(*++argv);
+
+ sc_token = (char *) malloc(sc_len);
+ if (sc_token == NULL)
+ panic("Insufficient virtual memory");
+} /* init_scanner */
+
+/*
+ * token() fetches a token from the input stream
+ */
+static int
+token()
+{
+ int idx;
+
+ while (1) {
+ memset(sc_token, 0, sc_len);
+ sc_tokid = EOF;
+ 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 (*sct == '/')
+ 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(tok)
+ 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(desired)
+ int desired;
+{
+ if (token() != desired)
+ plonk(sc_tokid); /* and we die here... */
+} /* expect */
+
+
+/*
+ * dateadd() adds a number of minutes to a date. It is extraordinarily
+ * stupid regarding day-of-month overflow, and will most likely not
+ * work properly
+ */
+static void
+dateadd(minutes, tm)
+ int minutes;
+ struct tm *tm;
+{
+ /* increment days */
+
+ while (minutes > 24*60) {
+ minutes -= 24*60;
+ tm->tm_mday++;
+ }
+
+ /* increment hours */
+ while (minutes > 60) {
+ minutes -= 60;
+ tm->tm_hour++;
+ if (tm->tm_hour > 23) {
+ tm->tm_mday++;
+ tm->tm_hour = 0;
+ }
+ }
+
+ /* increment minutes */
+ tm->tm_min += minutes;
+
+ if (tm->tm_min > 59) {
+ tm->tm_hour++;
+ tm->tm_min -= 60;
+
+ if (tm->tm_hour > 23) {
+ tm->tm_mday++;
+ tm->tm_hour = 0;
+ }
+ }
+} /* dateadd */
+
+
+/*
+ * plus() parses a now + time
+ *
+ * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS]
+ *
+ */
+static void
+plus(tm)
+ struct tm *tm;
+{
+ int delay;
+
+ expect(NUMBER);
+
+ delay = atoi(sc_token);
+
+ switch (token()) {
+ case WEEKS:
+ delay *= 7;
+ case DAYS:
+ delay *= 24;
+ case HOURS:
+ delay *= 60;
+ case MINUTES:
+ dateadd(delay, tm);
+ return;
+ }
+ plonk(sc_tokid);
+} /* plus */
+
+
+/*
+ * tod() computes the time of day
+ * [NUMBER [DOT NUMBER] [AM|PM]]
+ */
+static void
+tod(tm)
+ 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("garbeld 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)
+ hour += 12;
+ 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) && tm->tm_hour > hour)
+ tm->tm_mday++;
+
+ 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(tm, mday, mon, year)
+ struct tm *tm;
+ long mday, mon, year;
+{
+ if (year > 99) {
+ if (year > 1899)
+ year -= 1900;
+ else
+ panic("garbled time");
+ }
+
+ 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] |
+ * |NUMBER [SLASH NUMBER [SLASH NUMBER]]|
+ * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/
+ */
+static void
+month(tm)
+ struct tm *tm;
+{
+ long year= (-1);
+ long mday, mon;
+ int tlen;
+
+ switch (sc_tokid) {
+ case PLUS:
+ plus(tm);
+ break;
+
+ case TOMORROW:
+ /* do something tomorrow */
+ tm->tm_mday ++;
+ 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)-1;
+ if (token() == NUMBER) {
+ year = atol(sc_token);
+ token();
+ }
+ assign_date(tm, mday, mon, 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(argc, argv)
+ 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: /* now is optional prefix for PLUS tree */
+ expect(PLUS);
+ 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;
+ case NOON:
+ hr += 12;
+ case MIDNIGHT:
+ if (runtime.tm_hour >= hr)
+ runtime.tm_mday++;
+ runtime.tm_hour = hr;
+ runtime.tm_min = 0;
+ token();
+ /* fall through to month setting */
+ default:
+ month(&runtime);
+ break;
+ } /* ugly case statement */
+ expect(EOF);
+
+ /*
+ * adjust for daylight savings time
+ */
+ runtime.tm_isdst = -1;
+ runtimer = mktime(&runtime);
+ if (runtime.tm_isdst > 0) {
+ runtimer -= 3600;
+ runtimer = mktime(&runtime);
+ }
+
+ if (runtimer < 0)
+ panic("garbled time");
+
+ if (nowtimer > runtimer)
+ panic("Trying to travel back in time");
+
+ return runtimer;
+} /* parsetime */
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