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iostat.c revision 1.10
      1  1.10   scottr /*	$NetBSD: iostat.c,v 1.10 1996/10/25 18:21:58 scottr Exp $	*/
      2   1.9  thorpej 
      3   1.9  thorpej /*
      4   1.9  thorpej  * Copyright (c) 1996 John M. Vinopal
      5   1.9  thorpej  * All rights reserved.
      6   1.9  thorpej  *
      7   1.9  thorpej  * Redistribution and use in source and binary forms, with or without
      8   1.9  thorpej  * modification, are permitted provided that the following conditions
      9   1.9  thorpej  * are met:
     10   1.9  thorpej  * 1. Redistributions of source code must retain the above copyright
     11   1.9  thorpej  *    notice, this list of conditions and the following disclaimer.
     12   1.9  thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     13   1.9  thorpej  *    notice, this list of conditions and the following disclaimer in the
     14   1.9  thorpej  *    documentation and/or other materials provided with the distribution.
     15   1.9  thorpej  * 3. All advertising materials mentioning features or use of this software
     16   1.9  thorpej  *    must display the following acknowledgement:
     17   1.9  thorpej  *      This product includes software developed for the NetBSD Project
     18   1.9  thorpej  *      by John M. Vinopal.
     19   1.9  thorpej  * 4. The name of the author may not be used to endorse or promote products
     20   1.9  thorpej  *    derived from this software without specific prior written permission.
     21   1.9  thorpej  *
     22   1.9  thorpej  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23   1.9  thorpej  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24   1.9  thorpej  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25   1.9  thorpej  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26   1.9  thorpej  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     27   1.9  thorpej  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     28   1.9  thorpej  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     29   1.9  thorpej  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     30   1.9  thorpej  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31   1.9  thorpej  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32   1.9  thorpej  * SUCH DAMAGE.
     33   1.9  thorpej  */
     34   1.8  thorpej 
     35   1.1      cgd /*-
     36   1.6      cgd  * Copyright (c) 1986, 1991, 1993
     37   1.9  thorpej  *      The Regents of the University of California.  All rights reserved.
     38   1.1      cgd  *
     39   1.1      cgd  * Redistribution and use in source and binary forms, with or without
     40   1.1      cgd  * modification, are permitted provided that the following conditions
     41   1.1      cgd  * are met:
     42   1.1      cgd  * 1. Redistributions of source code must retain the above copyright
     43   1.1      cgd  *    notice, this list of conditions and the following disclaimer.
     44   1.1      cgd  * 2. Redistributions in binary form must reproduce the above copyright
     45   1.1      cgd  *    notice, this list of conditions and the following disclaimer in the
     46   1.1      cgd  *    documentation and/or other materials provided with the distribution.
     47   1.1      cgd  * 3. All advertising materials mentioning features or use of this software
     48   1.1      cgd  *    must display the following acknowledgement:
     49   1.9  thorpej  *      This product includes software developed by the University of
     50   1.9  thorpej  *      California, Berkeley and its contributors.
     51   1.1      cgd  * 4. Neither the name of the University nor the names of its contributors
     52   1.1      cgd  *    may be used to endorse or promote products derived from this software
     53   1.1      cgd  *    without specific prior written permission.
     54   1.1      cgd  *
     55   1.1      cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     56   1.1      cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     57   1.1      cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     58   1.1      cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     59   1.1      cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     60   1.1      cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     61   1.1      cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     62   1.1      cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     63   1.1      cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     64   1.1      cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     65   1.1      cgd  * SUCH DAMAGE.
     66   1.1      cgd  */
     67   1.1      cgd 
     68   1.1      cgd #ifndef lint
     69   1.6      cgd static char copyright[] =
     70   1.6      cgd "@(#) Copyright (c) 1986, 1991, 1993\n\
     71   1.9  thorpej         The Regents of the University of California.  All rights reserved.\n";
     72   1.1      cgd #endif /* not lint */
     73   1.1      cgd 
     74   1.1      cgd #ifndef lint
     75   1.8  thorpej #if 0
     76   1.9  thorpej static char sccsid[] = "@(#)iostat.c    8.2 (Berkeley) 1/26/94";
     77   1.8  thorpej #else
     78  1.10   scottr static char *rcsid = "$NetBSD: iostat.c,v 1.10 1996/10/25 18:21:58 scottr Exp $"
     79   1.9  thorpej ;
     80   1.8  thorpej #endif
     81   1.1      cgd #endif /* not lint */
     82   1.1      cgd 
     83   1.1      cgd #include <sys/dkstat.h>
     84   1.9  thorpej #include <sys/time.h>
     85   1.6      cgd 
     86   1.6      cgd #include <err.h>
     87   1.6      cgd #include <ctype.h>
     88   1.6      cgd #include <signal.h>
     89   1.1      cgd #include <stdio.h>
     90   1.1      cgd #include <stdlib.h>
     91   1.1      cgd #include <string.h>
     92   1.6      cgd #include <unistd.h>
     93   1.1      cgd 
     94   1.9  thorpej #include "dkstats.h"
     95   1.1      cgd 
     96   1.9  thorpej /* Defined in dkstats.c */
     97   1.9  thorpej extern struct _disk cur;
     98   1.9  thorpej extern int  	dk_ndrive;
     99   1.9  thorpej 
    100   1.9  thorpej /* Namelist and memory files. */
    101   1.9  thorpej char	*nlistf, *memf;
    102   1.9  thorpej 
    103   1.9  thorpej int		hz, reps, interval;
    104   1.9  thorpej static int	todo = 0;
    105   1.9  thorpej 
    106   1.9  thorpej #define ISSET(x, a)	((x) & (a))
    107   1.9  thorpej #define SHOW_CPU	0x0001
    108   1.9  thorpej #define SHOW_TTY	0x0002
    109   1.9  thorpej #define SHOW_STATS_1	0x0004
    110   1.9  thorpej #define SHOW_STATS_2	0x0008
    111   1.9  thorpej #define SHOW_TOTALS	0x0080
    112   1.9  thorpej 
    113   1.9  thorpej static void cpustats __P((void));
    114   1.9  thorpej static void disk_stats __P((double));
    115   1.9  thorpej static void disk_stats2 __P((double));
    116   1.9  thorpej static void header __P((int));
    117   1.9  thorpej static void usage __P((void));
    118   1.9  thorpej static void display __P((void));
    119   1.9  thorpej static void selectdrives __P((int, char **));
    120   1.9  thorpej 
    121   1.9  thorpej void dkswap __P((void));
    122   1.9  thorpej void dkreadstats __P((void));
    123   1.9  thorpej int dkinit __P((int));
    124   1.1      cgd 
    125   1.6      cgd int
    126   1.1      cgd main(argc, argv)
    127   1.1      cgd 	int argc;
    128   1.6      cgd 	char *argv[];
    129   1.1      cgd {
    130   1.9  thorpej 	int ch, hdrcnt;
    131   1.9  thorpej 	struct timeval	tv;
    132   1.9  thorpej 
    133   1.9  thorpej 	while ((ch = getopt(argc, argv, "Cc:dDIM:N:Tw:")) != EOF)
    134   1.1      cgd 		switch(ch) {
    135   1.1      cgd 		case 'c':
    136   1.6      cgd 			if ((reps = atoi(optarg)) <= 0)
    137   1.6      cgd 				errx(1, "repetition count <= 0.");
    138   1.1      cgd 			break;
    139   1.9  thorpej 		case 'C':
    140   1.9  thorpej 			todo |= SHOW_CPU;
    141   1.9  thorpej 			break;
    142   1.9  thorpej 		case 'd':
    143   1.9  thorpej 			todo |= SHOW_STATS_1;
    144   1.9  thorpej 			break;
    145   1.9  thorpej 		case 'D':
    146   1.9  thorpej 			todo |= SHOW_STATS_2;
    147   1.9  thorpej 			break;
    148   1.9  thorpej 		case 'I':
    149   1.9  thorpej 			todo |= SHOW_TOTALS;
    150   1.9  thorpej 			break;
    151   1.1      cgd 		case 'M':
    152   1.6      cgd 			memf = optarg;
    153   1.1      cgd 			break;
    154   1.1      cgd 		case 'N':
    155   1.6      cgd 			nlistf = optarg;
    156   1.1      cgd 			break;
    157   1.9  thorpej 		case 'T':
    158   1.9  thorpej 			todo |= SHOW_TTY;
    159   1.9  thorpej 			break;
    160   1.1      cgd 		case 'w':
    161   1.6      cgd 			if ((interval = atoi(optarg)) <= 0)
    162   1.6      cgd 				errx(1, "interval <= 0.");
    163   1.1      cgd 			break;
    164   1.1      cgd 		case '?':
    165   1.1      cgd 		default:
    166   1.1      cgd 			usage();
    167   1.1      cgd 		}
    168   1.1      cgd 	argc -= optind;
    169   1.1      cgd 	argv += optind;
    170   1.1      cgd 
    171   1.9  thorpej 	if (!ISSET(todo, SHOW_CPU | SHOW_TTY | SHOW_STATS_1 | SHOW_STATS_2))
    172   1.9  thorpej 		todo |= SHOW_CPU | SHOW_TTY | SHOW_STATS_1;
    173   1.9  thorpej 
    174   1.6      cgd 	/*
    175   1.6      cgd 	 * Discard setgid privileges if not the running kernel so that bad
    176   1.6      cgd 	 * guys can't print interesting stuff from kernel memory.
    177   1.6      cgd 	 */
    178   1.6      cgd 	if (nlistf != NULL || memf != NULL)
    179   1.6      cgd 		setgid(getgid());
    180   1.6      cgd 
    181   1.9  thorpej 	dkinit(0);
    182   1.9  thorpej 	dkreadstats();
    183   1.9  thorpej 	selectdrives(argc, argv);
    184   1.1      cgd 
    185   1.9  thorpej 	tv.tv_sec = interval;
    186   1.9  thorpej 	tv.tv_usec = 0;
    187   1.1      cgd 
    188   1.9  thorpej 	/* print a new header on sigcont */
    189   1.9  thorpej 	(void)signal(SIGCONT, header);
    190   1.1      cgd 
    191   1.1      cgd 	for (hdrcnt = 1;;) {
    192   1.1      cgd 		if (!--hdrcnt) {
    193   1.9  thorpej 			header(0);
    194   1.1      cgd 			hdrcnt = 20;
    195   1.1      cgd 		}
    196   1.9  thorpej 
    197   1.9  thorpej 		if (!ISSET(todo, SHOW_TOTALS))
    198   1.9  thorpej 			dkswap();
    199   1.9  thorpej 		display();
    200   1.1      cgd 
    201   1.1      cgd 		if (reps >= 0 && --reps <= 0)
    202   1.1      cgd 			break;
    203   1.9  thorpej 		select(0, NULL, NULL, NULL, &tv);
    204   1.9  thorpej 		dkreadstats();
    205   1.1      cgd 	}
    206   1.1      cgd 	exit(0);
    207   1.1      cgd }
    208   1.1      cgd 
    209   1.9  thorpej static void
    210   1.9  thorpej header(signo)
    211   1.6      cgd 	int signo;
    212   1.1      cgd {
    213   1.1      cgd 	register int i;
    214   1.1      cgd 
    215   1.9  thorpej 	/* Main Headers. */
    216   1.9  thorpej 	if (ISSET(todo, SHOW_TTY))
    217   1.9  thorpej 		(void)printf("      tty");
    218   1.9  thorpej 
    219   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_1))
    220   1.9  thorpej 	for (i = 0; i < dk_ndrive; i++)
    221   1.9  thorpej 		if (cur.dk_select[i])
    222   1.9  thorpej 			(void)printf("            %3.3s ", cur.dk_name[i]);
    223   1.9  thorpej 
    224   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_2))
    225   1.9  thorpej 	for (i = 0; i < dk_ndrive; i++)
    226   1.9  thorpej 		if (cur.dk_select[i])
    227   1.9  thorpej 			(void)printf("           %3.3s ", cur.dk_name[i]);
    228   1.9  thorpej 
    229   1.9  thorpej 	if (ISSET(todo, SHOW_CPU))
    230   1.9  thorpej 		(void)printf("            cpu");
    231   1.9  thorpej 	printf("\n");
    232   1.9  thorpej 
    233   1.9  thorpej 	/* Sub-Headers. */
    234   1.9  thorpej 	if (ISSET(todo, SHOW_TTY))
    235   1.9  thorpej 		printf(" tin tout");
    236   1.9  thorpej 
    237   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_1))
    238   1.1      cgd 	for (i = 0; i < dk_ndrive; i++)
    239   1.9  thorpej 		if (cur.dk_select[i])
    240   1.9  thorpej 			if (ISSET(todo, SHOW_TOTALS))
    241  1.10   scottr 				(void)printf("  KB/t xfr MB   ");
    242   1.9  thorpej 			else
    243  1.10   scottr 				(void)printf("  KB/t t/s MB/s ");
    244   1.9  thorpej 
    245   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_2))
    246   1.1      cgd 	for (i = 0; i < dk_ndrive; i++)
    247   1.9  thorpej 		if (cur.dk_select[i])
    248  1.10   scottr 			(void)printf("   KB xfr time ");
    249   1.9  thorpej 
    250   1.9  thorpej 	if (ISSET(todo, SHOW_CPU))
    251   1.9  thorpej 		(void)printf(" us ni sy in id");
    252   1.9  thorpej 	printf("\n");
    253   1.1      cgd }
    254   1.1      cgd 
    255   1.9  thorpej static void
    256   1.9  thorpej disk_stats(etime)
    257   1.9  thorpej double etime;
    258   1.1      cgd {
    259   1.1      cgd 	register int dn;
    260   1.9  thorpej 	double atime, mbps;
    261   1.1      cgd 
    262   1.1      cgd 	for (dn = 0; dn < dk_ndrive; ++dn) {
    263   1.9  thorpej 		if (!cur.dk_select[dn])
    264   1.1      cgd 			continue;
    265   1.9  thorpej 
    266   1.9  thorpej 		/* average Kbytes per transfer. */
    267   1.9  thorpej 		if (cur.dk_xfer[dn])
    268   1.9  thorpej 			mbps = (cur.dk_bytes[dn] / (1024.0)) / cur.dk_xfer[dn];
    269   1.9  thorpej 		else
    270   1.9  thorpej 			mbps = 0.0;
    271   1.9  thorpej 		(void)printf(" %5.2f", mbps);
    272   1.9  thorpej 
    273   1.9  thorpej 		/* average transfers per second. */
    274   1.9  thorpej 		(void)printf(" %3.0f", cur.dk_xfer[dn] / etime);
    275   1.9  thorpej 
    276   1.9  thorpej 		/* time busy in disk activity */
    277   1.9  thorpej 		atime = (double)cur.dk_time[dn].tv_sec +
    278   1.9  thorpej 			((double)cur.dk_time[dn].tv_usec / (double)1000000);
    279   1.9  thorpej 
    280   1.9  thorpej 		/* Megabytes per second. */
    281   1.9  thorpej 		if (atime != 0.0)
    282   1.9  thorpej 			mbps = cur.dk_bytes[dn] / (double)(1024 * 1024);
    283   1.9  thorpej 		else
    284   1.9  thorpej 			mbps = 0;
    285   1.9  thorpej 		(void)printf(" %4.2f ", mbps / etime);
    286   1.1      cgd 	}
    287   1.1      cgd }
    288   1.1      cgd 
    289   1.9  thorpej static void
    290   1.9  thorpej disk_stats2(etime)
    291   1.9  thorpej double etime;
    292   1.9  thorpej {
    293   1.9  thorpej 	register int dn;
    294   1.9  thorpej 	double atime;
    295   1.9  thorpej 
    296   1.9  thorpej 	for (dn = 0; dn < dk_ndrive; ++dn) {
    297   1.9  thorpej 		if (!cur.dk_select[dn])
    298   1.9  thorpej 			continue;
    299   1.9  thorpej 
    300   1.9  thorpej 		/* average kbytes per second. */
    301   1.9  thorpej 		(void)printf(" %4.0f", cur.dk_bytes[dn] / (1024.0) / etime);
    302   1.9  thorpej 
    303   1.9  thorpej 		/* average transfers per second. */
    304   1.9  thorpej 		(void)printf(" %3.0f", cur.dk_xfer[dn] / etime);
    305   1.9  thorpej 
    306   1.9  thorpej 		/* average time busy in disk activity. */
    307   1.9  thorpej 		atime = (double)cur.dk_time[dn].tv_sec +
    308   1.9  thorpej 			((double)cur.dk_time[dn].tv_usec / (double)1000000);
    309   1.9  thorpej 		(void)printf(" %4.2f ", atime / etime);
    310   1.9  thorpej 	}
    311   1.9  thorpej }
    312   1.9  thorpej 
    313   1.9  thorpej static void
    314   1.1      cgd cpustats()
    315   1.1      cgd {
    316   1.1      cgd 	register int state;
    317   1.1      cgd 	double time;
    318   1.1      cgd 
    319   1.1      cgd 	time = 0;
    320   1.1      cgd 	for (state = 0; state < CPUSTATES; ++state)
    321   1.1      cgd 		time += cur.cp_time[state];
    322   1.9  thorpej 	if (!time)
    323   1.9  thorpej 		time = 1.0;
    324   1.9  thorpej 	/* States are generally never 100% and can use %3.0f. */
    325   1.1      cgd 	for (state = 0; state < CPUSTATES; ++state)
    326   1.9  thorpej 		printf("%3.0f", 100. * cur.cp_time[state] / time);
    327   1.1      cgd }
    328   1.1      cgd 
    329   1.9  thorpej static void
    330   1.1      cgd usage()
    331   1.1      cgd {
    332   1.1      cgd 	(void)fprintf(stderr,
    333   1.9  thorpej "usage: iostat [-CdDIT] [-c count] [-M core] [-N system] [-w wait] [drives]\n");
    334   1.1      cgd 	exit(1);
    335   1.9  thorpej }
    336   1.9  thorpej 
    337   1.9  thorpej static void
    338   1.9  thorpej display()
    339   1.9  thorpej {
    340   1.9  thorpej 	int	i;
    341   1.9  thorpej 	double	etime;
    342   1.9  thorpej 
    343   1.9  thorpej 	/* Sum up the elapsed ticks. */
    344   1.9  thorpej 	etime = 0.0;
    345   1.9  thorpej 	for (i = 0; i < CPUSTATES; i++) {
    346   1.9  thorpej 		etime += cur.cp_time[i];
    347   1.9  thorpej 	}
    348   1.9  thorpej 	if (etime == 0.0)
    349   1.9  thorpej 		etime = 1.0;
    350   1.9  thorpej 	/* Convert to seconds. */
    351   1.9  thorpej 	etime /= (float)hz;
    352   1.9  thorpej 
    353   1.9  thorpej 	/* If we're showing totals only, then don't divide by the
    354   1.9  thorpej 	 * system time.
    355   1.9  thorpej 	 */
    356   1.9  thorpej 	if (ISSET(todo, SHOW_TOTALS))
    357   1.9  thorpej 		etime = 1.0;
    358   1.9  thorpej 
    359   1.9  thorpej 	if (ISSET(todo, SHOW_TTY))
    360   1.9  thorpej 		printf("%4.0f %4.0f", cur.tk_nin / etime, cur.tk_nout / etime);
    361   1.9  thorpej 
    362   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_1))
    363   1.9  thorpej 		disk_stats(etime);
    364   1.9  thorpej 
    365   1.9  thorpej 	if (ISSET(todo, SHOW_STATS_2))
    366   1.9  thorpej 		disk_stats2(etime);
    367   1.9  thorpej 
    368   1.9  thorpej 	if (ISSET(todo, SHOW_CPU))
    369   1.9  thorpej 		cpustats();
    370   1.9  thorpej 
    371   1.9  thorpej 	(void)printf("\n");
    372   1.9  thorpej 	(void)fflush(stdout);
    373   1.9  thorpej }
    374   1.9  thorpej 
    375   1.9  thorpej static void
    376   1.9  thorpej selectdrives(argc, argv)
    377   1.9  thorpej int	argc;
    378   1.9  thorpej char	*argv[];
    379   1.9  thorpej {
    380   1.9  thorpej 	int	i, ndrives;
    381   1.9  thorpej 
    382   1.9  thorpej 	/*
    383   1.9  thorpej 	 * Choose drives to be displayed.  Priority goes to (in order) drives
    384   1.9  thorpej 	 * supplied as arguments and default drives.  If everything isn't
    385   1.9  thorpej 	 * filled in and there are drives not taken care of, display the first
    386   1.9  thorpej 	 * few that fit.
    387   1.9  thorpej 	 *
    388   1.9  thorpej 	 * The backward compatibility #ifdefs permit the syntax:
    389   1.9  thorpej 	 *	iostat [ drives ] [ interval [ count ] ]
    390   1.9  thorpej 	 */
    391   1.9  thorpej #define	BACKWARD_COMPATIBILITY
    392   1.9  thorpej 	for (ndrives = 0; *argv; ++argv) {
    393   1.9  thorpej #ifdef	BACKWARD_COMPATIBILITY
    394   1.9  thorpej 		if (isdigit(**argv))
    395   1.9  thorpej 			break;
    396   1.9  thorpej #endif
    397   1.9  thorpej 		for (i = 0; i < dk_ndrive; i++) {
    398   1.9  thorpej 			if (strcmp(cur.dk_name[i], *argv))
    399   1.9  thorpej 				continue;
    400   1.9  thorpej 			cur.dk_select[i] = 1;
    401   1.9  thorpej 			++ndrives;
    402   1.9  thorpej 		}
    403   1.9  thorpej 	}
    404   1.9  thorpej #ifdef	BACKWARD_COMPATIBILITY
    405   1.9  thorpej 	if (*argv) {
    406   1.9  thorpej 		interval = atoi(*argv);
    407   1.9  thorpej 		if (*++argv)
    408   1.9  thorpej 			reps = atoi(*argv);
    409   1.9  thorpej 	}
    410   1.9  thorpej #endif
    411   1.9  thorpej 
    412   1.9  thorpej 	if (interval) {
    413   1.9  thorpej 		if (!reps)
    414   1.9  thorpej 			reps = -1;
    415   1.9  thorpej 	} else
    416   1.9  thorpej 		if (reps)
    417   1.9  thorpej 			interval = 1;
    418   1.9  thorpej 
    419   1.9  thorpej 	/* Pick up to 4 drives if none specified. */
    420   1.9  thorpej 	if (ndrives == 0)
    421   1.9  thorpej 		for (i = 0; i < dk_ndrive && ndrives < 4; i++) {
    422   1.9  thorpej 			if (cur.dk_select[i])
    423   1.9  thorpej 				continue;
    424   1.9  thorpej 			cur.dk_select[i] = 1;
    425   1.9  thorpej 			++ndrives;
    426   1.9  thorpej 		}
    427   1.1      cgd }
    428