/*    Date manipulation routines   Copyright (C) 1999, Joe Orton <joe@orton.demon.co.uk>                                                                        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 of the License, 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.*/#ifdef HAVE_CONFIG_H#include <config.h>#endif#include <sys/types.h>#include <time.h>#ifdef HAVE_STDLIB_H#include <stdlib.h>#endif#include <stdio.h>#include <dates.h>/* Generic date manipulation routines. *//* RFC1123: Sun, 06 Nov 1994 08:49:37 GMT */#define RFC1123_FORMAT "%3s, %02d %3s %4d %02d:%02d:%02d GMT"/* RFC850:  Sunday, 06-Nov-94 08:49:37 GMT */#define RFC1036_FORMAT "%s, %2d-%3s-%2d %2d:%2d:%2d GMT"/* asctime: Wed Jun 30 21:49:08 1993 */#define ASCTIME_FORMAT "%3s %3s %2d %2d:%2d:%2d %4d"const char *rfc1123_weekdays[7] = {     "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };const char *short_months[12] = {     "Jan", "Feb", "Mar", "Apr", "May", "Jun",    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};/* Returns the time/date GMT, in RFC1123-type format: eg *  Sun, 06 Nov 1994 08:49:37 GMT. */char *rfc1123_date( const time_t anytime ) {    struct tm *gmt;    char *ret;    gmt = gmtime( &anytime );    ret = malloc( 29 + 1 ); /* dates are 29 chars long *//*  it goes: Sun, 06 Nov 1994 08:49:37 GMT */    snprintf( ret, 30, RFC1123_FORMAT,	      rfc1123_weekdays[gmt->tm_wday], gmt->tm_mday, 	      short_months[gmt->tm_mon], 1900 + gmt->tm_year, 	      gmt->tm_hour, gmt->tm_min, gmt->tm_sec );        return ret;}/* Takes an RFC1123-formatted date string and returns the time_t. * Returns (time_t)-1 if the parse fails. */time_t rfc1123_parse( const char *date ) {    struct tm gmt = {0};    static char wkday[4], mon[4];    int n;/*  it goes: Sun, 06 Nov 1994 08:49:37 GMT */    n = sscanf( date, RFC1123_FORMAT,	    wkday, &gmt.tm_mday, mon, &gmt.tm_year, &gmt.tm_hour,	    &gmt.tm_min, &gmt.tm_sec );    /* Is it portable to check n==7 here? */    gmt.tm_year -= 1900;    for( n=0; n<12; n++ )	if( strcmp( mon, short_months[n] ) == 0 )	    break;    /* tm_mon comes out as 12 if the month is corrupt, which is desired,     * since the mktime will then fail */    gmt.tm_mon = n;    return mktime( &gmt );}/* Takes a string containing a RFC1036-style date and returns the time_t */time_t rfc1036_parse( const char *date ) {    struct tm gmt = {0};    int n;    static char wkday[10], mon[4];    /* RFC850/1036 style dates: Sunday, 06-Nov-94 08:49:37 GMT */    n = sscanf( RFC1036_FORMAT,		wkday, &gmt.tm_mday, mon, &gmt.tm_year,		&gmt.tm_hour, &gmt.tm_min, &gmt.tm_sec );    /* portable to check n here? */    for( n=0; n<12; n++ )	if( strcmp( mon, short_months[n] ) == 0 )	    break;    /* tm_mon comes out as 12 if the month is corrupt, which is desired,     * since the mktime will then fail */    gmt.tm_mon = n;    return mktime( &gmt );}/* (as)ctime dates are like: *    Wed Jun 30 21:49:08 1993 */time_t asctime_parse( const char *date ) {    struct tm gmt = {0};    int n;    static char wkday[4], mon[4];    n = sscanf( ASCTIME_FORMAT,		wkday, mon, &gmt.tm_mday, 		&gmt.tm_hour, &gmt.tm_min, &gmt.tm_sec,		&gmt.tm_year );    /* portable to check n here? */    for( n=0; n<12; n++ )	if( strcmp( mon, short_months[n] ) == 0 )	    break;    /* tm_mon comes out as 12 if the month is corrupt, which is desired,     * since the mktime will then fail */    gmt.tm_mon = n;    return mktime( &gmt );}#undef RFC1036_FORMAT#undef ASCTIME_FORMAT#undef RFC1123_FORMAT#ifdef RFC1123_TESTint main( int argc, char **argv ) {    time_t now, in;    char *out;    if( argc > 1 ) {	printf( "Got: %s\n", argv[1] );	in = rfc1123_parse( argv[1] );	printf( "Parsed: %d\n", in );	out = rfc1123_date( in );	printf( "Back again: %s\n", out );    } else {	now = time(NULL);	out = rfc1123_date(now);	in = rfc1123_parse(out);	printf( "time(NULL) = %d\n", now );	printf( "RFC1123 Time: [%s]\n", out );	printf( "Parsed = %d\n", in );	out = rfc1123_date( in );	printf( "Back again: [%s]\n", out );    }    return 0;}#endif