root/usr/src/cmd/time/time.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 *      Time a command
 */

#include        <stdio.h>
#include        <signal.h>
#include        <errno.h>
#include        <stdlib.h>
#include        <unistd.h>
#include        <libintl.h>
#include        <locale.h>
#include        <limits.h>
#include        <sys/types.h>
#include        <sys/times.h>
#include        <sys/wait.h>

/*
 * The following use of HZ/10 will work correctly only if HZ is a multiple
 * of 10.  However the only values for HZ now in use are 100 for the 3B
 * and 60 for other machines.
 *
 * The first value was HZ/10. Since HZ should be gotten from sysconf()
 * it is dynamically initialized at entry to the main program.
 */
static clock_t quant[] = { 10, 10, 10, 6, 10, 6, 10, 10, 10 };
static char *pad  = "000      ";
static char *sep  = "\0\0.\0:\0:\0\0";
static char *nsep = "\0\0.\0 \0 \0\0";

static void usage(void);
static void printt(char *, clock_t);

int
main(int argc, char **argv)
{
        struct tms      buffer;
        pid_t           p;
        int             status;
        int             pflag           = 0;
        int             c;
        int             clock_tick      = CLK_TCK;
        clock_t         before, after;

        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
        (void) textdomain(TEXT_DOMAIN);

        while ((c = getopt(argc, argv, "p")) != EOF)
                switch (c) {
                case 'p':
                        pflag++;
                        break;
                case '?':
                        usage();
                }

        argc -= optind;
        argv += optind;

        /*
         * time(1) is only accurate to a tenth of a second.  We need to
         * determine the number of clock ticks in a tenth of a second in
         * order to later divide away what we don't care about.
         */
        quant[0] = clock_tick/10;

        before = times(&buffer);
        if (argc < 1)
                usage();
        p = fork();
        if (p == (pid_t)-1) {
                perror("time");
                exit(2);
        }
        if (p == (pid_t)0) {
                (void) execvp(argv[0], &argv[0]);
                perror(argv[0]);
                if (errno == ENOENT)
                        exit(127);
                else
                        exit(126);
        }
        (void) signal(SIGINT, SIG_IGN);
        (void) signal(SIGQUIT, SIG_IGN);
        while (wait(&status) != p);
        if ((status & 0377) != '\0')
                (void) fprintf(stderr, "time: %s\n",
                    gettext("command terminated abnormally."));
        after = times(&buffer);
        (void) fprintf(stderr, "\n");
        if (pflag)
                (void) fprintf(stderr, "real %.2f\nuser %.2f\nsys %.2f\n",
                    (double)(after-before)/clock_tick,
                    (double)buffer.tms_cutime/clock_tick,
                    (double)buffer.tms_cstime/clock_tick);
        else {
                printt("real", (after-before));
                printt("user", buffer.tms_cutime);
                printt("sys ", buffer.tms_cstime);
        }

        return ((status & 0xff00)
                ? (status >> 8)
                : ((status & 0x00ff) ? ((status & ~WCOREFLG) | 0200) : 0));
}


static void
printt(char *s, clock_t a)
{
        int i;
        char digit[9];
        char c;
        int nonzero;

        a /= quant[0];  /* Divide away the accuracy we don't care about */

        /*
         * We now have the number of tenths of seconds elapsed in terms of
         * ticks. Loop through to determine the actual digits.
         */
        for (i = 1; i < 9; i++) {
                digit[i] = a % quant[i];
                a /= quant[i];
        }
        (void) fprintf(stderr, s);
        nonzero = 0;
        while (--i > 0) {
                c = (digit[i] != 0) ? digit[i]+'0' : (nonzero ? '0': pad[i]);
                if (c != '\0')
                        (void) putc(c, stderr);
                nonzero |= digit[i];
                c = nonzero?sep[i]:nsep[i];
                if (c != '\0')
                        (void) putc(c, stderr);
        }
        (void) fprintf(stderr, "\n");
}

static void
usage(void)
{
        (void) fprintf(stderr,
            gettext("usage: time [-p] utility [argument...]\n"));
        exit(1);
}