/*      $NetBSD: pathconf.c,v 1.7 2004/03/25 19:36:27 atatat Exp $      */

/*
 * 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. 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.
 */

#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
#if 0
static char sccsid[] = "@(#)pathconf.c  8.1 (Berkeley) 6/6/93";
#else
static char rcsid[] = "$NetBSD: pathconf.c,v 1.7 2004/03/25 19:36:27 atatat Exp $";
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>

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

#define PC_NAMES { \
        { 0, 0 }, \
        { "link_max", CTLTYPE_INT }, \
        { "max_canon", CTLTYPE_INT }, \
        { "max_input", CTLTYPE_INT }, \
        { "name_max", CTLTYPE_INT }, \
        { "path_max", CTLTYPE_INT }, \
        { "pipe_buf", CTLTYPE_INT }, \
        { "chown_restricted", CTLTYPE_INT }, \
        { "no_trunc", CTLTYPE_INT }, \
        { "vdisable", CTLTYPE_INT }, \
}
#define PC_MAXID 10

struct ctlname pcnames[] = PC_NAMES;
char names[BUFSIZ];

struct list {
        struct  ctlname *list;
        int     size;
};
struct list pclist = { pcnames, PC_MAXID };

int     Aflag, aflag, nflag, wflag, stdinflag;

int
main(argc, argv)
        int argc;
        char *argv[];
{
        char *path;
        int ch;

        while ((ch = getopt(argc, argv, "Aan")) != -1) {
                switch (ch) {

                case 'A':
                        Aflag = 1;
                        break;

                case 'a':
                        aflag = 1;
                        break;

                case 'n':
                        nflag = 1;
                        break;

                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc == 0)
                usage();
        path = *argv++;
        if (strcmp(path, "-") == 0)
                stdinflag = 1;
        argc--;
        if (Aflag || aflag) {
                listall(path, &pclist);
                exit(0);
        }
        if (argc == 0)
                usage();
        while (argc-- > 0)
                parse(path, *argv, 1);
        exit(0);
}

/*
 * List all variables known to the system.
 */
listall(path, lp)
        char *path;
        struct list *lp;
{
        int lvl2;

        if (lp->list == 0)
                return;
        for (lvl2 = 0; lvl2 < lp->size; lvl2++) {
                if (lp->list[lvl2].ctl_name == 0)
                        continue;
                parse(path, lp->list[lvl2].ctl_name, Aflag);
        }
}

/*
 * Parse a name into an index.
 * Lookup and print out the attribute if it exists.
 */
parse(pathname, string, flags)
        char *pathname;
        char *string;
        int flags;
{
        int indx, value;
        char *bufp, buf[BUFSIZ];

        bufp = buf;
        snprintf(buf, BUFSIZ, "%s", string);
        if ((indx = findname(string, "top", &bufp, &pclist)) == -1)
                return;
        if (bufp) {
                fprintf(stderr, "name %s in %s is unknown\n", *bufp, string);
                return;
        }
        if (stdinflag)
                value = fpathconf(0, indx);
        else
                value = pathconf(pathname, indx);
        if (value == -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 (!nflag)
                fprintf(stdout, "%s = ", string);
        fprintf(stdout, "%d\n", value);
}

/*
 * Scan a list of names searching for a particular name.
 */
findname(string, level, bufp, namelist)
        char *string;
        const 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);
}

usage()
{

        (void)fprintf(stderr, "usage:\t%s\n\t%s\n\t%s\n",
            "pathname [-n] variable ...",
            "pathname [-n] -a", "pathname [-n] -A");
        exit(1);
}