getdate.c

一个类似Unix下tar命令的tar程序

    else if (strlen(buff) == 4 && buff[3] == '.') {
	abbrev = 1;
	buff[3] = '\0';
    }
    else
	abbrev = 0;

    for (tp = MonthDayTable; tp->name; tp++) {
	if (abbrev) {
	    if (strncmp(buff, tp->name, 3) == 0) {
		yylval.Number = tp->value;
		return tp->type;
	    }
	}
	else if (strcmp(buff, tp->name) == 0) {
	    yylval.Number = tp->value;
	    return tp->type;
	}
    }

    for (tp = TimezoneTable; tp->name; tp++)
	if (strcmp(buff, tp->name) == 0) {
	    yylval.Number = tp->value;
	    return tp->type;
	}

    for (tp = UnitsTable; tp->name; tp++)
	if (strcmp(buff, tp->name) == 0) {
	    yylval.Number = tp->value;
	    return tp->type;
	}

    /* Strip off any plural and try the units table again. */
    i = strlen(buff) - 1;
    if (buff[i] == 's') {
	buff[i] = '\0';
	for (tp = UnitsTable; tp->name; tp++)
	    if (strcmp(buff, tp->name) == 0) {
		yylval.Number = tp->value;
		return tp->type;
	    }
	buff[i] = 's';		/* Put back for "this" in OtherTable. */
    }

    for (tp = OtherTable; tp->name; tp++)
	if (strcmp(buff, tp->name) == 0) {
	    yylval.Number = tp->value;
	    return tp->type;
	}

    /* Military timezones. */
    if (buff[1] == '\0' && isalpha(*buff)) {
	for (tp = MilitaryTable; tp->name; tp++)
	    if (strcmp(buff, tp->name) == 0) {
		yylval.Number = tp->value;
		return tp->type;
	    }
    }

    /* Drop out any periods and try the timezone table again. */
    for (i = 0, p = q = buff; *q; q++)
	if (*q != '.')
	    *p++ = *q;
	else
	    i++;
    *p = '\0';
    if (i)
	for (tp = TimezoneTable; tp->name; tp++)
	    if (strcmp(buff, tp->name) == 0) {
		yylval.Number = tp->value;
		return tp->type;
	    }

    return tID;
}


int
yylex()
{
    register char	c;
    register char	*p;
    char		buff[20];
    int			Count;
    int			sign;

    for ( ; ; ) {
	while (isspace(*yyInput))
	    yyInput++;

	if (isdigit(c = *yyInput) || c == '-' || c == '+') {
	    if (c == '-' || c == '+') {
		sign = c == '-' ? -1 : 1;
		if (!isdigit(*++yyInput))
		    /* skip the '-' sign */
		    continue;
	    }
	    else
		sign = 0;
	    for (yylval.Number = 0; isdigit(c = *yyInput++); )
		yylval.Number = 10 * yylval.Number + c - '0';
	    yyInput--;
	    if (sign < 0)
		yylval.Number = -yylval.Number;
	    return sign ? tSNUMBER : tUNUMBER;
	}
	if (isalpha(c)) {
	    for (p = buff; isalpha(c = *yyInput++) || c == '.'; )
		if (p < &buff[sizeof buff - 1])
		    *p++ = c;
	    *p = '\0';
	    yyInput--;
	    return LookupWord(buff);
	}
	if (c != '(')
	    return *yyInput++;
	Count = 0;
	do {
	    c = *yyInput++;
	    if (c == '\0')
		return c;
	    if (c == '(')
		Count++;
	    else if (c == ')')
		Count--;
	} while (Count > 0);
    }
}


time_t
get_date(p, now)
    char		*p;
    struct timeb	*now;
{
    struct tm		*tm;
    struct timeb	ftz;
    time_t		Start;
    time_t		tod;

    yyInput = p;
    if (now == NULL) {
	now = &ftz;
#if	defined(NEED_TZSET)
	(void)time(&ftz.time);
	/* Set the timezone global. */
	tzset();
	ftz.timezone = (int) timezone / 60;
#else
	(void)ftime(&ftz);
#endif	/* defined(NEED_TZSET) */
    }

    tm = localtime(&now->time);
    yyYear = tm->tm_year;
    yyMonth = tm->tm_mon + 1;
    yyDay = tm->tm_mday;
    yyTimezone = now->timezone;
    yyDSTmode = DSTmaybe;
    yyHour = 0;
    yyMinutes = 0;
    yySeconds = 0;
    yyMeridian = MER24;
    yyRelSeconds = 0;
    yyRelMonth = 0;
    yyHaveDate = 0;
    yyHaveDay = 0;
    yyHaveRel = 0;
    yyHaveTime = 0;
    yyHaveZone = 0;

    if (yyparse()
     || yyHaveTime > 1 || yyHaveZone > 1 || yyHaveDate > 1 || yyHaveDay > 1)
	return -1;

    if (yyHaveDate || yyHaveTime || yyHaveDay) {
	Start = Convert(yyMonth, yyDay, yyYear, yyHour, yyMinutes, yySeconds,
		    yyMeridian, yyDSTmode);
	if (Start < 0)
	    return -1;
    }
    else {
	Start = now->time;
	if (!yyHaveRel)
	    Start -= ((tm->tm_hour * 60L + tm->tm_min) * 60L) + tm->tm_sec;
    }

    Start += yyRelSeconds;
    Start += RelativeMonth(Start, yyRelMonth);

    if (yyHaveDay && !yyHaveDate) {
	tod = RelativeDate(Start, yyDayOrdinal, yyDayNumber);
	Start += tod;
    }

    /* Have to do *something* with a legitimate -1 so it's distinguishable
     * from the error return value.  (Alternately could set errno on error.) */
    return Start == -1 ? 0 : Start;
}


#if	defined(TEST)

/* ARGSUSED */
main(ac, av)
    int		ac;
    char	*av[];
{
    char	buff[128];
    time_t	d;

    (void)printf("Enter date, or blank line to exit.\n\t> ");
    (void)fflush(stdout);
    while (gets(buff) && buff[0]) {
	d = get_date(buff, (struct timeb *)NULL);
	if (d == -1)
	    (void)printf("Bad format - couldn't convert.\n");
	else
	    (void)printf("%s", ctime(&d));
	(void)printf("\t> ");
	(void)fflush(stdout);
    }
    exit(0);
    /* NOTREACHED */
}
#endif	/* defined(TEST) */
yytabelem yyexca[] ={
-1, 1,
	0, -1,
	-2, 0,
	};
# define YYNPROD 39
# define YYLAST 221
yytabelem yyact[]={

    13,    11,    22,    39,    16,    12,    18,    17,    15,     9,
    10,    40,    44,    20,    43,    42,    46,    29,    35,    34,
    33,    30,    27,    32,    31,    41,    36,    28,    37,    14,
     8,     7,     6,     5,     4,     3,     2,     1,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,    45,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
     0,     0,     0,     0,     0,     0,    40,     0,     0,     0,
     0,    38,     0,    21,     0,     0,    19,    24,    23,    26,
    25 };
yytabelem yypact[]={

 -1000,  -258, -1000, -1000, -1000, -1000, -1000, -1000, -1000,   -45,
 -1000, -1000,  -245,   -17,  -240,  -241, -1000, -1000, -1000, -1000,
  -247, -1000,  -248,  -249, -1000, -1000, -1000,   -18, -1000, -1000,
 -1000, -1000, -1000,   -55,   -22, -1000,  -252, -1000, -1000,  -253,
 -1000,  -255, -1000,  -250, -1000, -1000, -1000 };
yytabelem yypgo[]={

     0,    28,    37,    36,    35,    34,    33,    32,    31,    30,
    29 };
yytabelem yyr1[]={

     0,     2,     2,     3,     3,     3,     3,     3,     3,     4,
     4,     4,     4,     4,     5,     5,     7,     7,     7,     6,
     6,     6,     6,     6,     6,     8,     8,    10,    10,    10,
    10,    10,    10,    10,    10,    10,     9,     1,     1 };
yytabelem yyr2[]={

     0,     0,     4,     3,     3,     3,     3,     3,     2,     5,
     9,     9,    13,    13,     3,     3,     3,     5,     5,     7,
    11,     5,     9,     5,     7,     5,     2,     5,     5,     3,
     5,     5,     3,     5,     5,     3,     3,     1,     3 };
yytabelem yychk[]={

 -1000,    -2,    -3,    -4,    -5,    -6,    -7,    -8,    -9,   267,
   268,   259,   263,   258,   -10,   266,   262,   265,   264,   261,
    58,   258,    47,   263,   262,   265,   264,   267,    44,   257,
   262,   265,   264,   267,   267,   267,    44,    -1,   266,    58,
   261,    47,   267,   267,   267,    -1,   266 };
yytabelem yydef[]={

     1,    -2,     2,     3,     4,     5,     6,     7,     8,    36,
    14,    15,     0,    16,    26,     0,    29,    32,    35,     9,
     0,    18,     0,    23,    27,    31,    34,    21,    17,    25,
    28,    30,    33,    37,    19,    24,     0,    10,    11,     0,
    38,     0,    22,    37,    20,    12,    13 };
typedef struct { char *t_name; int t_val; } yytoktype;
#ifndef YYDEBUG
#	define YYDEBUG	0	/* don't allow debugging */
#endif

#if YYDEBUG

yytoktype yytoks[] =
{
	"tAGO",	257,
	"tDAY",	258,
	"tDAYZONE",	259,
	"tID",	260,
	"tMERIDIAN",	261,
	"tMINUTE_UNIT",	262,
	"tMONTH",	263,
	"tMONTH_UNIT",	264,
	"tSEC_UNIT",	265,
	"tSNUMBER",	266,
	"tUNUMBER",	267,
	"tZONE",	268,
	"-unknown-",	-1	/* ends search */
};

char * yyreds[] =
{
	"-no such reduction-",
	"spec : /* empty */",
	"spec : spec item",
	"item : time",
	"item : zone",
	"item : date",
	"item : day",
	"item : rel",
	"item : number",
	"time : tUNUMBER tMERIDIAN",
	"time : tUNUMBER ':' tUNUMBER o_merid",
	"time : tUNUMBER ':' tUNUMBER tSNUMBER",
	"time : tUNUMBER ':' tUNUMBER ':' tUNUMBER o_merid",
	"time : tUNUMBER ':' tUNUMBER ':' tUNUMBER tSNUMBER",
	"zone : tZONE",
	"zone : tDAYZONE",
	"day : tDAY",
	"day : tDAY ','",
	"day : tUNUMBER tDAY",
	"date : tUNUMBER '/' tUNUMBER",
	"date : tUNUMBER '/' tUNUMBER '/' tUNUMBER",
	"date : tMONTH tUNUMBER",
	"date : tMONTH tUNUMBER ',' tUNUMBER",
	"date : tUNUMBER tMONTH",
	"date : tUNUMBER tMONTH tUNUMBER",
	"rel : relunit tAGO",
	"rel : relunit",
	"relunit : tUNUMBER tMINUTE_UNIT",
	"relunit : tSNUMBER tMINUTE_UNIT",
	"relunit : tMINUTE_UNIT",
	"relunit : tSNUMBER tSEC_UNIT",
	"relunit : tUNUMBER tSEC_UNIT",
	"relunit : tSEC_UNIT",
	"relunit : tSNUMBER tMONTH_UNIT",
	"relunit : tUNUMBER tMONTH_UNIT",
	"relunit : tMONTH_UNIT",
	"number : tUNUMBER",
	"o_merid : /* empty */",
	"o_merid : tMERIDIAN",
};
#endif /* YYDEBUG */
#ident	"@(#)yaccpar	2.3 - 88/05/27"

/*
** Skeleton parser driver for yacc output
*/

/*
** yacc user known macros and defines
*/
#define YYERROR		goto yyerrlab
#define YYACCEPT	return(0)
#define YYABORT		return(1)
#define YYBACKUP( newtoken, newvalue )\
{\
	if ( yychar >= 0 || ( yyr2[ yytmp ] >> 1 ) != 1 )\
	{\
		yyerror( "syntax error - cannot backup" );\
		goto yyerrlab;\
	}\
	yychar = newtoken;\
	yystate = *yyps;\
	yylval = newvalue;\
	goto yynewstate;\
}
#define YYRECOVERING()	(!!yyerrflag)
#ifndef YYDEBUG
#	define YYDEBUG	1	/* make debugging available */
#endif

/*
** user known globals
*/
int yydebug;			/* set to 1 to get debugging */

/*
** driver internal defines
*/
#define YYFLAG		(-1000)

/*
** global variables used by the parser
*/
YYSTYPE yyv[ YYMAXDEPTH ];	/* value stack */
int yys[ YYMAXDEPTH ];		/* state stack */

YYSTYPE *yypv;			/* top of value stack */
int *yyps;			/* top of state stack */

int yystate;			/* current state */
int yytmp;			/* extra var (lasts between blocks) */

int yynerrs;			/* number of errors */
int yyerrflag;			/* error recovery flag */
int yychar;			/* current input token number */



/*
** yyparse - return 0 if worked, 1 if syntax error not recovered from
*/
int
yyparse()
{
	register YYSTYPE *yypvt;	/* top of value stack for $vars */

	/*
	** Initialize externals - yyparse may be called more than once
	*/
	yypv = &yyv[-1];
	yyps = &yys[-1];
	yystate = 0;
	yytmp = 0;
	yynerrs = 0;
	yyerrflag = 0;
	yychar = -1;

	goto yystack;
	{
		register YYSTYPE *yy_pv;	/* top of value stack */
		register int *yy_ps;		/* top of state stack */
		register int yy_state;		/* current state */
		register int  yy_n;		/* internal state number info */

		/*
		** get globals into registers.
		** branch to here only if YYBACKUP was called.
		*/
	yynewstate:
		yy_pv = yypv;
		yy_ps = yyps;
		yy_state = yystate;
		goto yy_newstate;

		/*
		** get globals into registers.
		** either we just started, or we just finished a reduction
		*/
	yystack:
		yy_pv = yypv;
		yy_ps = yyps;
		yy_state = yystate;

		/*
		** top of for (;;) loop while no reductions done
		*/
	yy_stack:
		/*
		** put a state and value onto the stacks
		*/
#if YYDEBUG
		/*
		** if debugging, look up token value in list of value vs.
		** name pairs.  0 and negative (-1) are special values.
		** Note: linear search is used since time is not a real
		** consideration while debugging.
		*/
		if ( yydebug )
		{
			register int yy_i;

			printf( "State %d, token ", yy_state );
			if ( yychar == 0 )
				printf( "end-of-file\n" );
			else if ( yychar < 0 )
				printf( "-none-\n" );
			else
			{
				for ( yy_i = 0; yytoks[yy_i].t_val >= 0;
					yy_i++ )
				{
					if ( yytoks[yy_i].t_val == yychar )
						break;
				}
				printf( "%s\n", yytoks[yy_i].t_name );
			}
		}
#endif /* YYDEBUG */
		if ( ++yy_ps >= &yys[ YYMAXDEPTH ] )	/* room on stack? */
		{
			yyerror( "yacc stack overflow" );
			YYABORT;