system_cmds-279.1.tar.gz

[apple/system_cmds.git] / sysctl.tproj / sysctl.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
 * Reserved.  This file contains Original Code and/or Modifications of
 * Original Code as defined in and that are subject to the Apple Public
 * Source License Version 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
 * this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License."
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 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.
 */

 /*
 Modified November 1, 2000, by Ryan Rempel, ryan.rempel@utoronto.ca
 
 The Darwin sysctl mechanism is in a state of flux. Parts of the kernel use the old
 style of BSD sysctl definition, and other parts use the new style. The sysctl (8)
 command that shipped with Darwin 1.2 (OS X PB) did not allow you to access
 all possible sysctl values. In particular, it did not permit access to sysctl values
 created by kernel extensions--hence my particular interest. The freeBSD sysctl (8)
 command compiled and ran under Darwin 1.2, and it did permit access to 
 sysctl values created by kernel extensions, as well as several others. However, it 
 did not permit access to many other values which the Darwin 1.2 sysctl could access.
 
 What I have done is merge the Darwin 1.2 sysctl and the freeBSD sysctl. Essentially,
 there are two points of merger. When showing all values (i.e. -a, -A, or -X), sysctl now
 runs the Darwin 1.2 routine to show all values, and then the freeBSD routine. This does
 result in some duplication. When getting or setting a particular value, sysctl now tries
 the freeBSD way first. If it cannot find the value, then it tries the Darwin 1.2 way.
 
 There are a few oddities which this creates (aside from some duplication with -a, -A,
 and -X). The freeBSD version of sysctl now supports two extra options, -b and -X. 
 In this syctl, those options are supported where the value is retrieved by the freeBSD
 routine, and have no effect where the value is retrieved by the Darwin 1.2 routine.
 The freeBSD sysctl uses a ':' to separate the name and the value, whereas Darwin 1.2's
 sysctl uses a '='. I have left this way, as it lets you know which routine was used,
 should it matter.
 
 I have also fixed several lines which gave warnings previously, one of which appears
 to have been an actual bug (bufp was dereferenced when it shouldn't have been).
 I have also incoporated my previous patch to permit setting kern.hostid as an unsigned 
 integer. In the freeBSD side of the code, I have incorporated a general fix for
 setting values where the format is specified as unsigned integer.
 */
 
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1993\n\
        The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)sysctl.c    8.5 (Berkeley) 5/9/95";
#endif /* not lint */

#include <sys/param.h>
#include <sys/gmon.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#ifdef __APPLE__
#include <mach/machine/vm_param.h>
#include <mach/machine/vm_types.h>
#include <mach/mach_types.h>
#else
#include <vm/vm_param.h>
#endif /* __APPLE__ */
#include <machine/cpu.h>

#include <errno.h>
#include <ctype.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/resource.h>
#include <err.h>

struct ctlname topname[] = CTL_NAMES;
struct ctlname kernname[] = CTL_KERN_NAMES;
struct ctlname vmname[] = CTL_VM_NAMES;
struct ctlname hwname[] = CTL_HW_NAMES;
struct ctlname username[] = CTL_USER_NAMES;
struct ctlname debugname[CTL_DEBUG_MAXID];
struct ctlname *vfsname;
#ifdef CTL_MACHDEP_NAMES
struct ctlname machdepname[] = CTL_MACHDEP_NAMES;
#endif
char names[BUFSIZ];
int lastused;

struct list {
        struct  ctlname *list;
        int     size;
};
struct list toplist = { topname, CTL_MAXID };
struct list secondlevel[] = {
        { 0, 0 },                       /* CTL_UNSPEC */
        { kernname, KERN_MAXID },       /* CTL_KERN */
        { vmname, VM_MAXID },           /* CTL_VM */
        { 0, 0 },                       /* CTL_VFS */
        { 0, 0 },                       /* CTL_NET */
        { 0, CTL_DEBUG_MAXID },         /* CTL_DEBUG */
        { 0, 0 },                       /* CTL_HW */
#ifdef CTL_MACHDEP_NAMES
        { machdepname, CPU_MAXID },     /* CTL_MACHDEP */
#else
        { 0, 0 },                       /* CTL_MACHDEP */
#endif
        { username, USER_MAXID },       /* CTL_USER_NAMES */
};

static int      Aflag, aflag, bflag, nflag, wflag, Xflag;
static int      foundSome = 0;

void listall(char *prefix, struct list *lp);
void old_parse(char *string, int flags);
void debuginit();
void vfsinit();
int  findname(char *string, char *level, char **bufp, struct list *namelist);
void usage();

static void     parse(char *string, int flags);
static int      oidfmt(int *, int, char *, u_int *);
static int      show_var(int *, int, int);
static int      sysctl_all (int *oid, int len);
static int      name2oid(char *, int *);

/*
 * Variables requiring special processing.
 */
#define CLOCK           0x00000001
#define BOOTTIME        0x00000002
#define CONSDEV         0x00000004

int
main(argc, argv)
        int argc;
        char *argv[];
{
//      extern char *optarg;   // unused
        extern int optind;
        int ch, lvl1;

        while ((ch = getopt(argc, argv, "AabnwX")) != EOF) {
                switch (ch) {
                        case 'A': Aflag = 1; break;
                        case 'a': aflag = 1; break;
                        case 'b': bflag = 1; break;
                        case 'n': nflag = 1; break;
                        case 'w': wflag = 1; break;
                        case 'X': Xflag = Aflag = 1; break;
                        default: usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc == 0 && (Aflag || aflag)) {
                debuginit();
                vfsinit();
                for (lvl1 = 1; lvl1 < CTL_MAXID; lvl1++)
                        listall(topname[lvl1].ctl_name, &secondlevel[lvl1]);
                exit (sysctl_all(0, 0));
        }
        if (argc == 0)
                usage();
        for (; *argv != NULL; ++argv)
                parse(*argv, 1);
        exit(0);
}

/*
 * List all variables known to the system.
 */
void
listall(prefix, lp)
        char *prefix;
        struct list *lp;
{
        int lvl2;
        char *cp, name[BUFSIZ];

        if (lp->list == 0)
                return;
        strcpy(name, prefix);
        cp = &name[strlen(name)];
        *cp++ = '.';
        for (lvl2 = 0; lvl2 < lp->size; lvl2++) {
                if (lp->list[lvl2].ctl_name == 0)
                        continue;
                strcpy(cp, lp->list[lvl2].ctl_name);
                old_parse(name, Aflag);
        }
}

/*
 * Parse a name into a MIB entry.
 * Lookup and print out the MIB entry if it exists.
 * Set a new value if requested.
 */
void
old_parse(string, flags)
        char *string;
        int flags;
{
        int indx, type, state, len;
        size_t size;
        int special = 0;
        void *newval = 0;
        int intval, newsize = 0;
        unsigned int uintval;
        int useUnsignedInt = 0;
        quad_t quadval;
        struct list *lp;
        struct vfsconf vfc;
        int mib[CTL_MAXNAME];
        char *cp, *bufp, buf[BUFSIZ] /*, strval[BUFSIZ] */ ;

        bufp = buf;
        snprintf(buf, BUFSIZ, "%s", string);
        if ((cp = strchr(string, '=')) != NULL) {
                if (!wflag) {
                        fprintf(stderr, "Must specify -w to set variables\n");
                        exit(2);
                }
                *strchr(buf, '=') = '\0';
                *cp++ = '\0';
                while (isspace(*cp))
                        cp++;
                newval = cp;
                newsize = strlen(cp);
        }
        if ((indx = findname(string, "top", &bufp, &toplist)) == -1)
                return;
        mib[0] = indx;
        if (indx == CTL_VFS)
                vfsinit();
        if (indx == CTL_DEBUG)
                debuginit();
        lp = &secondlevel[indx];
        if (lp->list == 0) {
                if (!foundSome) fprintf(stderr, "%s: class is not implemented\n",
                    topname[indx].ctl_name);
                return;
        }
        if (bufp == NULL) {
                listall(topname[indx].ctl_name, lp);
                return;
        }
        if ((indx = findname(string, "second", &bufp, lp)) == -1)
                return;
        mib[1] = indx;
        type = lp->list[indx].ctl_type;
        len = 2;
        switch (mib[0]) {

        case CTL_KERN:
                switch (mib[1]) {
                case KERN_PROF:
                        mib[2] = GPROF_STATE;
                        size = sizeof state;
                        if (sysctl(mib, 3, &state, &size, NULL, 0) < 0) {
                                if (flags == 0)
                                        return;
                                if (!nflag)
                                        fprintf(stdout, "%s: ", string);
                                fprintf(stderr,
                                    "kernel is not compiled for profiling\n");
                                return;
                        }
                        if (!nflag)
                                fprintf(stdout, "%s: %s\n", string,
                                    state == GMON_PROF_OFF ? "off" : "running");
                        return;
                case KERN_VNODE:
                case KERN_FILE:
                        if (flags == 0)
                                return;
                        fprintf(stderr,
                            "Use pstat to view %s information\n", string);
                        return;
                case KERN_PROC:
                        if (flags == 0)
                                return;
                        fprintf(stderr,
                            "Use ps to view %s information\n", string);
                        return;
                case KERN_CLOCKRATE:
                        special |= CLOCK;
                        break;
                case KERN_BOOTTIME:
                        special |= BOOTTIME;
                        break;
                case KERN_HOSTID:
                        useUnsignedInt = 1;
                        break;
                }
                break;

        case CTL_HW:
                useUnsignedInt = 1;
                break;

        case CTL_VM:
                if (mib[1] == VM_LOADAVG) {     /* XXX this is bogus */
                        double loads[3];

                        getloadavg(loads, 3);
                        if (!nflag)
                                fprintf(stdout, "%s: ", string);
                        fprintf(stdout, "%.2f %.2f %.2f\n", 
                            loads[0], loads[1], loads[2]);
                        return;
                }
                if (flags == 0)
                        return;
                fprintf(stderr,
                    "Use vmstat or systat to view %s information\n", string);
                return;
        
        case CTL_DEBUG:
                mib[2] = CTL_DEBUG_VALUE;
                len = 3;
                break;

        case CTL_MACHDEP:
#ifdef CPU_CONSDEV
                if (mib[1] == CPU_CONSDEV)
                        special |= CONSDEV;
#endif
                break;

        case CTL_VFS:
                mib[3] = mib[1];
                mib[1] = VFS_GENERIC;
                mib[2] = VFS_CONF;
                len = 4;
                size = sizeof vfc;
                if (sysctl(mib, 4, &vfc, &size, (void *)0, (size_t)0) < 0) {
                        perror("vfs print");
                        return;
                }
                if (flags == 0 && vfc.vfc_refcount == 0)
                        return;
                if (!nflag)
                        fprintf(stdout, "%s has %d mounted instance%s\n",
                            string, vfc.vfc_refcount,
                            vfc.vfc_refcount != 1 ? "s" : "");
                else
                        fprintf(stdout, "%d\n", vfc.vfc_refcount);
                return;

        case CTL_USER:
                break;

        default:
                fprintf(stderr, "Illegal top level value: %d\n", mib[0]);
                return;
        
        }
        if (bufp) {
                fprintf(stderr, "name %s in %s is unknown\n", bufp, string);
                return;
        }
        if (newsize > 0) {
                switch (type) {
                case CTLTYPE_INT:
                        if (useUnsignedInt) {   
                                uintval = strtoul(newval, 0, 0);
                                newval = &uintval;
                                newsize = sizeof uintval;
                        } else {
                        intval = atoi(newval);
                        newval = &intval;
                        newsize = sizeof intval;
                        }
                        break;

                case CTLTYPE_QUAD:
                        sscanf(newval, "%qd", &quadval);
                        newval = &quadval;
                        newsize = sizeof quadval;
                        break;
                }
        }
        size = BUFSIZ;
        if (sysctl(mib, len, buf, &size, newsize ? newval : 0, newsize) == -1) {
                if (flags == 0)
                        return;
                switch (errno) {
                case EOPNOTSUPP:
                        fprintf(stderr, "%s: value is not available\n", string);
                        return;
                case ENOTDIR:
                        fprintf(stderr, "%s: specification is incomplete\n",
                            string);
                        return;
                case ENOMEM:
                        fprintf(stderr, "%s: type is unknown to this program\n",
                            string);
                        return;
                default:
                        perror(string);
                        return;
                }
        }
        if (special & CLOCK) {
                struct clockinfo *clkp = (struct clockinfo *)buf;

                if (!nflag)
                        fprintf(stdout, "%s: ", string);
                fprintf(stdout,
                    "hz = %d, tick = %d, profhz = %d, stathz = %d\n",
                    clkp->hz, clkp->tick, clkp->profhz, clkp->stathz);
                return;
        }
        if (special & BOOTTIME) {
                struct timeval *btp = (struct timeval *)buf;

                if (!nflag)
                        fprintf(stdout, "%s = %s\n", string,
                            ctime((time_t *) &btp->tv_sec));
                else
                        fprintf(stdout, "%d\n", btp->tv_sec);
                return;
        }
        if (special & CONSDEV) {
                dev_t dev = *(dev_t *)buf;

                if (!nflag)
                        fprintf(stdout, "%s = %s\n", string,
                            devname(dev, S_IFCHR));
                else
                        fprintf(stdout, "0x%x\n", dev);
                return;
        }
        switch (type) {
        case CTLTYPE_INT:
                if (newsize == 0) {
                        if (!nflag)
                                fprintf(stdout, "%s = ", string);
                        fprintf(stdout, useUnsignedInt ? "%u\n" : "%d\n", *(int *)buf);
                } else {
                        if (!nflag)
                                fprintf(stdout, useUnsignedInt ? "%s: %u -> " : "%s: %d -> ", 
                                        string, *(int *)buf);
                        fprintf(stdout, useUnsignedInt ? "%u\n" : "%d\n", *(int *)newval);
                }
                return;

        case CTLTYPE_STRING:
                if (newsize == 0) {
                        if (!nflag)
                                fprintf(stdout, "%s = ", string);
                        fprintf(stdout, "%s\n", buf);
                } else {
                        if (!nflag)
                                fprintf(stdout, "%s: %s -> ", string, buf);
                        fprintf(stdout, "%s\n", (char *) newval);
                }
                return;

        case CTLTYPE_QUAD:
                if (newsize == 0) {
                        if (!nflag)
                                fprintf(stdout, "%s = ", string);
                        fprintf(stdout, "%qd\n", *(quad_t *)buf);
                } else {
                        if (!nflag)
                                fprintf(stdout, "%s: %qd -> ", string,
                                    *(quad_t *)buf);
                        fprintf(stdout, "%qd\n", *(quad_t *)newval);
                }
                return;

        case CTLTYPE_STRUCT:
                return;

        default:
        case CTLTYPE_NODE:
                fprintf(stderr, "%s: unknown type returned\n",
                    string);
                return;
        }
}

/*
 * Initialize the set of debugging names
 */
void debuginit()
{
        int mib[3], loc, i;
        size_t size;

        if (secondlevel[CTL_DEBUG].list != 0)
                return;
        secondlevel[CTL_DEBUG].list = debugname;
        mib[0] = CTL_DEBUG;
        mib[2] = CTL_DEBUG_NAME;
        for (loc = lastused, i = 0; i < CTL_DEBUG_MAXID; i++) {
                mib[1] = i;
                size = BUFSIZ - loc;
                if (sysctl(mib, 3, &names[loc], &size, NULL, 0) == -1)
                        continue;
                debugname[i].ctl_name = &names[loc];
                debugname[i].ctl_type = CTLTYPE_INT;
                loc += size;
        }
        lastused = loc;
}

/*
 * Initialize the set of filesystem names
 */
void vfsinit()
{
        int mib[4], maxtypenum, cnt, loc, size;
        struct vfsconf vfc;
        size_t buflen;

        if (secondlevel[CTL_VFS].list != 0)
                return;
        mib[0] = CTL_VFS;
        mib[1] = VFS_GENERIC;
        mib[2] = VFS_MAXTYPENUM;
        buflen = 4;
        if (sysctl(mib, 3, &maxtypenum, &buflen, (void *)0, (size_t)0) < 0)
                return;
        if ((vfsname = malloc(maxtypenum * sizeof(*vfsname))) == 0)
                return;
        memset(vfsname, 0, maxtypenum * sizeof(*vfsname));
        mib[2] = VFS_CONF;
        buflen = sizeof vfc;
        for (loc = lastused, cnt = 0; cnt < maxtypenum; cnt++) {
                mib[3] = cnt;
                if (sysctl(mib, 4, &vfc, &buflen, (void *)0, (size_t)0) < 0) {
                        if (errno == EOPNOTSUPP)
                                continue;
                        perror("vfsinit");
                        free(vfsname);
                        return;
                }
                strcat(&names[loc], vfc.vfc_name);
                vfsname[cnt].ctl_name = &names[loc];
                vfsname[cnt].ctl_type = CTLTYPE_INT;
                size = strlen(vfc.vfc_name) + 1;
                loc += size;
        }
        lastused = loc;
        secondlevel[CTL_VFS].list = vfsname;
        secondlevel[CTL_VFS].size = maxtypenum;
        return;
}

/*
 * Scan a list of names searching for a particular name.
 */
int
findname(string, level, bufp, namelist)
        char *string;
        char *level;
        char **bufp;
        struct list *namelist;
{
        char *name;
        int i;

        if (namelist->list == 0 || (name = strsep(bufp, ".")) == NULL) {
                fprintf(stderr, "%s: incomplete specification\n", string);
                return (-1);
        }
        for (i = 0; i < namelist->size; i++)
                if (namelist->list[i].ctl_name != NULL &&
                    strcmp(name, namelist->list[i].ctl_name) == 0)
                        break;
        if (i == namelist->size) {
                fprintf(stderr, "%s level name %s in %s is invalid\n",
                    level, name, string);
                return (-1);
        }
        return (i);
}

void usage()
{

        (void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n",
                "usage: sysctl [-bn] variable ...",
                "       sysctl [-bn] -w variable=value ...",
                "       sysctl [-bn] -a",
                "       sysctl [-bn] -A",
                "       sysctl [-bn] -X");
        exit(1);
}

/*
 * Parse a name into a MIB entry.
 * Lookup and print out the MIB entry if it exists.
 * Set a new value if requested.
 */
static void
parse(char *string, int flags)
{
        int len, i, j;
        void *newval = 0;
        int intval, newsize = 0;
        unsigned int uintval;
        quad_t quadval;
        int mib[CTL_MAXNAME];
        char *cp, *bufp, buf[BUFSIZ], fmt[BUFSIZ];
        u_int kind;

        bufp = buf;
        snprintf(buf, BUFSIZ, "%s", string);
        if ((cp = strchr(string, '=')) != NULL) {
                if (!wflag)
                        errx(2, "must specify -w to set variables");
                *strchr(buf, '=') = '\0';
                *cp++ = '\0';
                while (isspace(*cp))
                        cp++;
                newval = cp;
                newsize = strlen(cp);
        } else {
                if (wflag)
                        usage();
        }
        len = name2oid(bufp, mib);

        if (len < 0) {
                if (cp != NULL) {
                        while (*cp != '\0') cp--;
                        *cp = '=';
                }
                old_parse (string, flags);
                return;
        }

        if (oidfmt(mib, len, fmt, &kind))
                err(1, "couldn't find format of oid '%s'", bufp);

        if (!wflag) {
                if ((kind & CTLTYPE) == CTLTYPE_NODE) {
                        sysctl_all(mib, len);
                        foundSome = 1;
                        old_parse (string, flags);
                } else {
                        i = show_var(mib, len, 1);
                        if (!i && !bflag)
                                putchar('\n');
                }
        } else {
                if ((kind & CTLTYPE) == CTLTYPE_NODE)
                        errx(1, "oid '%s' isn't a leaf node", bufp);

                if (!(kind&CTLFLAG_WR))
                        errx(1, "oid '%s' is read only", bufp);
        
                switch (kind & CTLTYPE) {
                        case CTLTYPE_INT:
                                if ((*fmt == 'I') && (*(fmt + 1) == 'U')) {
                                        uintval = (unsigned int) strtoul (newval, NULL, 0);
                                        newval = &uintval;
                                        newsize = sizeof uintval;
                                } else {
                                        intval = (int) strtol(newval, NULL, 0);
                                        newval = &intval;
                                        newsize = sizeof intval;
                                }
                                break;
                        case CTLTYPE_STRING:
                                break;
                        case CTLTYPE_QUAD:
                                break;
                                sscanf(newval, "%qd", &quadval);
                                newval = &quadval;
                                newsize = sizeof quadval;
                                break;
                        default:
                                errx(1, "oid '%s' is type %d,"
                                        " cannot set that", bufp,
                                        kind & CTLTYPE);
                }

                i = show_var(mib, len, 1);
                if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
                        if (!i && !bflag)
                                putchar('\n');
                        switch (errno) {
                        case EOPNOTSUPP:
                                errx(1, "%s: value is not available", 
                                        string);
                        case ENOTDIR:
                                errx(1, "%s: specification is incomplete", 
                                        string);
                        case ENOMEM:
                                errx(1, "%s: type is unknown to this program", 
                                        string);
                        default:
                                warn("%s", string);
                                return;
                        }
                }
                if (!bflag)
                        printf(" -> ");
                i = nflag;
                nflag = 1;
                j = show_var(mib, len, 1);
                if (!j && !bflag)
                        putchar('\n');
                nflag = i;
        }
}

/* These functions will dump out various interesting structures. */

static int
S_clockinfo(int l2, void *p)
{
        struct clockinfo *ci = (struct clockinfo*)p;
        if (l2 != sizeof *ci)
                err(1, "S_clockinfo %d != %d", l2, sizeof *ci);
        printf("{ hz = %d, tick = %d, tickadj = %d, profhz = %d, stathz = %d }",
                ci->hz, ci->tick, ci->tickadj, ci->profhz, ci->stathz);
        return (0);
}

static int
S_loadavg(int l2, void *p)
{
        struct loadavg *tv = (struct loadavg*)p;

        if (l2 != sizeof *tv)
                err(1, "S_loadavg %d != %d", l2, sizeof *tv);

        printf("{ %.2f %.2f %.2f }",
                (double)tv->ldavg[0]/(double)tv->fscale,
                (double)tv->ldavg[1]/(double)tv->fscale,
                (double)tv->ldavg[2]/(double)tv->fscale);
        return (0);
}

static int
S_timeval(int l2, void *p)
{
        struct timeval *tv = (struct timeval*)p;
        time_t tv_sec;
        char *p1, *p2;

        if (l2 != sizeof *tv)
                err(1, "S_timeval %d != %d", l2, sizeof *tv);
        printf("{ sec = %ld, usec = %ld } ",
                (long) tv->tv_sec, (long) tv->tv_usec);
        tv_sec = tv->tv_sec;
        p1 = strdup(ctime(&tv_sec));
        for (p2=p1; *p2 ; p2++)
                if (*p2 == '\n')
                        *p2 = '\0';
        fputs(p1, stdout);
        return (0);
}

static int
T_dev_t(int l2, void *p)
{
        dev_t *d = (dev_t *)p;
        if (l2 != sizeof *d)
                err(1, "T_dev_T %d != %d", l2, sizeof *d);
        if ((int)(*d) != -1) {
                if (minor(*d) > 255 || minor(*d) < 0)
                        printf("{ major = %d, minor = 0x%x }",
                                major(*d), minor(*d));
                else
                        printf("{ major = %d, minor = %d }",
                                major(*d), minor(*d));
        }
        return (0);
}

/*
 * These functions uses a presently undocumented interface to the kernel
 * to walk the tree and get the type so it can print the value.
 * This interface is under work and consideration, and should probably
 * be killed with a big axe by the first person who can find the time.
 * (be aware though, that the proper interface isn't as obvious as it
 * may seem, there are various conflicting requirements.
 */

static int
name2oid(char *name, int *oidp)
{
        int oid[2];
        int i;
        size_t j;

        oid[0] = 0;
        oid[1] = 3;

        j = CTL_MAXNAME * sizeof (int);
        i = sysctl(oid, 2, oidp, &j, name, strlen(name));
        if (i < 0) 
                return i;
        j /= sizeof (int);
        return (j);
}

static int
oidfmt(int *oid, int len, char *fmt, u_int *kind)
{
        int qoid[CTL_MAXNAME+2];
        u_char buf[BUFSIZ];
        int i;
        size_t j;

        qoid[0] = 0;
        qoid[1] = 4;
        memcpy(qoid + 2, oid, len * sizeof(int));

        j = sizeof buf;
        i = sysctl(qoid, len + 2, buf, &j, 0, 0);
        if (i)
                err(1, "sysctl fmt %d %d %d", i, j, errno);

        if (kind)
                *kind = *(u_int *)buf;

        if (fmt)
                strcpy(fmt, (char *)(buf + sizeof(u_int)));
        return 0;
}

/*
 * This formats and outputs the value of one variable
 *
 * Returns zero if anything was actually output.
 * Returns one if didn't know what to do with this.
 * Return minus one if we had errors.
 */

static int
show_var(int *oid, int nlen, int show_masked)
{
        u_char buf[BUFSIZ], *val, *mval, *p;
        char name[BUFSIZ], /* descr[BUFSIZ], */ *fmt;
        int qoid[CTL_MAXNAME+2];
        int i;
        int retval;
        size_t j, len;
        u_int kind;
        int (*func)(int, void *) = 0;

        qoid[0] = 0;
        memcpy(qoid + 2, oid, nlen * sizeof(int));

        qoid[1] = 1;
        j = sizeof name;
        i = sysctl(qoid, nlen + 2, name, &j, 0, 0);
        if (i || !j)
                err(1, "sysctl name %d %d %d", i, j, errno);

        /* find an estimate of how much we need for this var */
        j = 0;
        i = sysctl(oid, nlen, 0, &j, 0, 0);
        j += j; /* we want to be sure :-) */

        val = mval = malloc(j);
        len = j;
        i = sysctl(oid, nlen, val, &len, 0, 0);
        if (i || !len) {
                retval = 1;
                goto RETURN;
        }

        if (bflag) {
                fwrite(val, 1, len, stdout);
                retval = 0;
                goto RETURN;
        }

        qoid[1] = 4;
        j = sizeof buf;
        i = sysctl(qoid, nlen + 2, buf, &j, 0, 0);
        if (i || !j)
                err(1, "sysctl fmt %d %d %d", i, j, errno);

        kind = *(u_int *)buf;
        if (!show_masked && (kind & CTLFLAG_MASKED)) {
                retval = 1;
                goto RETURN;
        }

        fmt = (char *)(buf + sizeof(u_int));

        p = val;
        switch (*fmt) {
        case '-':
                /* deprecated, do not print */
                retval = 0;
                goto RETURN;
                

        case 'A':
                if (!nflag)
                        printf("%s: ", name);
                printf("%s", p);
                retval = 0;
                goto RETURN;
                
        case 'I':
                if (!nflag)
                        printf("%s: ", name);
                fmt++;
                val = "";
                while (len >= sizeof(int)) {
                        if(*fmt == 'U')
                                printf("%s%u", val, *(unsigned int *)p);
                        else
                                printf("%s%d", val, *(int *)p);
                        val = " ";
                        len -= sizeof (int);
                        p += sizeof (int);
                }
                retval = 0;
                goto RETURN;

        case 'L':
                if (!nflag)
                        printf("%s: ", name);
                fmt++;
                val = "";
                while (len >= sizeof(long)) {
                        if(*fmt == 'U')
                                printf("%s%lu", val, *(unsigned long *)p);
                        else
                                printf("%s%ld", val, *(long *)p);
                        val = " ";
                        len -= sizeof (long);
                        p += sizeof (long);
                }
                retval = 0;
                goto RETURN;

        case 'P':
                if (!nflag)
                        printf("%s: ", name);
                printf("%p", *(void **)p);
                retval = 0;
                goto RETURN;

        case 'Q':
                if (!nflag)
                        printf("%s: ", name);
                fmt++;
                val = "";
                while (len >= sizeof(long long)) {
                        if(*fmt == 'U')
                                printf("%s%llu", val, *(unsigned long long *)p);
                        else
                                printf("%s%lld", val, *(long long *)p);
                        val = " ";
                        len -= sizeof (long long);
                        p += sizeof (long long);
                }
                retval = 0;
                goto RETURN;


        case 'T':
        case 'S':
                i = 0;
                if (!strcmp(fmt, "S,clockinfo"))        func = S_clockinfo;
                else if (!strcmp(fmt, "S,timeval"))     func = S_timeval;
                else if (!strcmp(fmt, "S,loadavg"))     func = S_loadavg;
                else if (!strcmp(fmt, "T,dev_t"))       func = T_dev_t;
                if (func) {
                        if (!nflag)
                                printf("%s: ", name);
                        retval = (*func)(len, p);
                        goto RETURN;
                }
                /* FALL THROUGH */
        default:
                if (!Aflag) {
                        retval = 1;
                        goto RETURN;
                }
                if (!nflag)
                        printf("%s: ", name);
                printf("Format:%s Length:%ld Dump:0x", fmt, len);
                while (len--) {
                        printf("%02x", *p++);
                        if (Xflag || p < val+16)
                                continue;
                        printf("...");
                        break;
                }
                retval = 0;
                goto RETURN;
        }

        retval = 1;
        RETURN:
        free(mval);
        return (retval);
}

static int
sysctl_all (int *oid, int len)
{
        int name1[22], name2[22];
        int i, j;
        size_t l1, l2;

        name1[0] = 0;
        name1[1] = 2;
        l1 = 2;
        if (len) {
                memcpy(name1+2, oid, len*sizeof (int));
                l1 += len;
        } else {
                name1[2] = 1;
                l1++;
        }
        while (1) {
                l2 = sizeof name2;
                j = sysctl(name1, l1, name2, &l2, 0, 0);
                if (j < 0) {
                        if (errno == ENOENT)
                                return 0;
                        else
                                err(1, "sysctl(getnext) %d %d", j, l2);
                }

                l2 /= sizeof (int);

                if (l2 < len)
                        return 0;

                for (i = 0; i < len; i++)
                        if (name2[i] != oid[i])
                                return 0;

                i = show_var(name2, l2, 0);
                if (!i && !bflag)
                        putchar('\n');

                memcpy(name1+2, name2, l2*sizeof (int));
                l1 = 2 + l2;
        }
}