shadow/libmisc/tz.c

/*
 * Copyright 1991 - 1994, Julianne Frances Haugh and Chip Rosenthal
 * 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.
 * 3. Neither the name of Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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.
 */

#include <config.h>

#ident "$Id$"

#include <stdio.h>
#include <string.h>
#include "defines.h"
#include "getdef.h"
/*
 * tz - return local timezone name
 *
 * tz() determines the name of the local timezone by reading the
 * contents of the file named by ``fname''.
 */
char *tz (const char *fname)
{
	FILE *fp = 0;
	static char tzbuf[BUFSIZ];
	const char *def_tz;

	if ((fp = fopen (fname, "r")) == NULL ||
	    fgets (tzbuf, sizeof (tzbuf), fp) == NULL) {
#ifndef USE_PAM
		if (!(def_tz = getdef_str ("ENV_TZ")) || def_tz[0] == '/')
			def_tz = "TZ=CST6CDT";
#endif				/* !USE_PAM */

		strcpy (tzbuf, def_tz);
	} else
		tzbuf[strlen (tzbuf) - 1] = '\0';

	if (fp)
		(void) fclose (fp);

	return tzbuf;
}