/*
 *----------------------------------------------------------------------------
 * Copyright (c) 2002, Daniel B. Hemmerich
 * All rights reserved.
 *----------------------------------------------------------------------------
 *
 *  * Redistribution and use in source and binary forms, with or without
 *    modification, are permitted provided that the following conditions
 *    are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 *  * 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.
 *
 *  * Neither the name of the ipex developers 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 COPYRIGHT HOLDERS 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.
 *----------------------------------------------------------------------------
 */

#ifndef lint
static const char rcsid[] = \
    "@(#) $Header: /usr/cvs/ipex/time.c,v 1.2 2004/08/05 23:00:35 modulus Exp $";
#endif

#include "ipex_includes.h"

const static char ncharset[] = "1234567890";
const static char scharset[] = "smhd";

void isvalid(char *expr);

unsigned long int
timer_secs(char *arg)
{
	unsigned long int secs = 0;
	char unit = 0;

	if (strchr(scharset, arg[strlen(arg) - 1])) {
		unit = arg[strlen(arg) - 1];
		arg[strlen(arg) - 1] = '\0';
	}
	switch(unit) {
	case 'm':
		secs = atol(arg) * 60;
		break;
	case 'h':
		secs = atol(arg) * 3600;
		break;
	case 'd':
		secs = atol(arg) * 86400;
		break;
	case 's':
	default:
		secs = atol(arg);
		break;
	}
	return (secs);
}

void
set_timer(char *arg)
{
	struct itimerval itv;

	isvalid(arg);
	memset(&itv, 0, sizeof(itv));
	itv.it_interval.tv_sec = 0;
	itv.it_interval.tv_usec = 0;
	itv.it_value.tv_sec = timer_secs(arg);
	if (setitimer(ITIMER_REAL, &itv, NULL) == -1)
		errx(EX_OSERR, "fatal: setitimer: %s", strerror(errno));
}

void
isvalid(char *expr)
{
	int nc = 0;

	while(*expr) {
		if (*(expr + 1) == '\0') {
			if (strchr(ncharset, *expr)) {
				nc++;
				break;
			}
			if (!nc)
				errx(EX_USAGE, "fatal: at least one digit " \
				    "for -t is required");
			if (!strchr(scharset, *expr))
				errx(EX_USAGE, "fatal: suffix for -t must be " \
				    "s m h or d");
			nc++;
			break;
		}
		if (!strchr(ncharset, *expr))
			errx(EX_USAGE, "fatal: -t requires a numeric unit" \
			    " with optional suffix (%c invalid)", *expr);
		expr++;
		nc++;
   	}
	if (!nc)
		errx(EX_USAGE, "fatal: -t requires a numeric unit with" \
		    " optional suffix");
}