freebsd-skq/lib/libc/gen/timezone.c
ed e7e5b53bf1 Replace index() and rindex() calls with strchr() and strrchr().
The index() and rindex() functions were marked LEGACY in the 2001
revision of POSIX and were subsequently removed from the 2008 revision.
The strchr() and strrchr() functions are part of the C standard.

This makes the source code a lot more consistent, as most of these C
files also call into other str*() routines. In fact, about a dozen
already perform strchr() calls.
2012-01-03 18:51:58 +00:00

130 lines
4.0 KiB
C

/*
* Copyright (c) 1987, 1993
* The Regents of the University of California. 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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, WHETHER 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)timezone.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define TZ_MAX_CHARS 255
char *_tztab(int, int);
/*
* timezone --
* The arguments are the number of minutes of time you are westward
* from Greenwich and whether DST is in effect. It returns a string
* giving the name of the local timezone. Should be replaced, in the
* application code, by a call to localtime.
*/
static char czone[TZ_MAX_CHARS]; /* space for zone name */
char *
timezone(int zone, int dst)
{
char *beg,
*end;
if ( (beg = getenv("TZNAME")) ) { /* set in environment */
if ((end = strchr(beg, ','))) { /* "PST,PDT" */
if (dst)
return(++end);
*end = '\0';
(void)strncpy(czone,beg,sizeof(czone) - 1);
czone[sizeof(czone) - 1] = '\0';
*end = ',';
return(czone);
}
return(beg);
}
return(_tztab(zone,dst)); /* default: table or created zone */
}
static struct zone {
int offset;
char *stdzone;
char *dlzone;
} zonetab[] = {
{-1*60, "MET", "MET DST"}, /* Middle European */
{-2*60, "EET", "EET DST"}, /* Eastern European */
{4*60, "AST", "ADT"}, /* Atlantic */
{5*60, "EST", "EDT"}, /* Eastern */
{6*60, "CST", "CDT"}, /* Central */
{7*60, "MST", "MDT"}, /* Mountain */
{8*60, "PST", "PDT"}, /* Pacific */
#ifdef notdef
/* there's no way to distinguish this from WET */
{0, "GMT", 0}, /* Greenwich */
#endif
{0*60, "WET", "WET DST"}, /* Western European */
{-10*60,"EST", "EST"}, /* Aust: Eastern */
{-10*60+30,"CST", "CST"}, /* Aust: Central */
{-8*60, "WST", 0}, /* Aust: Western */
{-1}
};
/*
* _tztab --
* check static tables or create a new zone name; broken out so that
* we can make a guess as to what the zone is if the standard tables
* aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE
* STANDARD LIBRARY.
*/
char *
_tztab(int zone, int dst)
{
struct zone *zp;
char sign;
for (zp = zonetab; zp->offset != -1;++zp) /* static tables */
if (zp->offset == zone) {
if (dst && zp->dlzone)
return(zp->dlzone);
if (!dst && zp->stdzone)
return(zp->stdzone);
}
if (zone < 0) { /* create one */
zone = -zone;
sign = '+';
}
else
sign = '-';
(void)snprintf(czone, sizeof(czone),
"GMT%c%d:%02d",sign,zone / 60,zone % 60);
return(czone);
}