/* Parse dates for touch.
Copyright (C) 1989, 1990, 1991 Free Software Foundation Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Written by Jim Kingdon and David MacKenzie. */
%{
#ifdef __GNUC__
#define alloca __builtin_alloca
#else
#ifdef sparc
#include <alloca.h>
#else
#ifdef _AIX
#pragma alloca
#else
char *alloca ();
#endif
#endif
#endif
#include <stdio.h>
#include <sys/types.h>
#include <time.h>
#define YYDEBUG 1
/* Lexical analyzer's current scan position in the input string. */
static char *curpos;
/* The return value. */
static struct tm t;
time_t mktime ();
#define yyparse posixtime_yyparse
static int yylex ();
static int yyerror ();
%}
%token DIGIT
%%
date :
digitpair /* month */
digitpair /* day */
digitpair /* hours */
digitpair /* minutes */
year
seconds {
if ($1 >= 1 && $1 <= 12)
t.tm_mon = $1 - 1;
else {
YYABORT;
}
if ($2 >= 1 && $2 <= 31)
t.tm_mday = $2;
else {
YYABORT;
}
if ($3 >= 0 && $3 <= 23)
t.tm_hour = $3;
else {
YYABORT;
}
if ($4 >= 0 && $4 <= 59)
t.tm_min = $4;
else {
YYABORT;
}
}
year : digitpair {
t.tm_year = $1;
/* Deduce the century based on the year.
See POSIX.2 section 4.63.3. */
if ($1 <= 68)
t.tm_year += 100;
}
| digitpair digitpair {
t.tm_year = $1 * 100 + $2;
if (t.tm_year < 1900) {
YYABORT;
} else
t.tm_year -= 1900;
}
| /* empty */ {
time_t now;
struct tm *tmp;
/* Use current year. */
time (&now);
tmp = localtime (&now);
t.tm_year = tmp->tm_year;
}
;
seconds : /* empty */ {
t.tm_sec = 0;
}
| '.' digitpair {
if ($2 >= 0 && $2 <= 61)
t.tm_sec = $2;
else {
YYABORT;
}
}
;
digitpair : DIGIT DIGIT {
$$ = $1 * 10 + $2;
}
;
%%
static int
yylex ()
{
char ch = *curpos++;
if (ch >= '0' && ch <= '9')
{
yylval = ch - '0';
return DIGIT;
}
else if (ch == '.' || ch == 0)
return ch;
else
return '?'; /* Cause an error. */
}
static int
yyerror ()
{
return 0;
}
/* Parse a POSIX-style date and return it, or (time_t)-1 for an error. */
time_t
posixtime (s)
char *s;
{
curpos = s;
/* Let mktime decide whether it is daylight savings time. */
t.tm_isdst = -1;
if (yyparse ())
return (time_t)-1;
else
return mktime (&t);
}
/* Parse a POSIX-style date and return it, or NULL for an error. */
struct tm *
posixtm (s)
char *s;
{
if (posixtime (s) == -1)
return NULL;
return &t;
}
