/*      $NetBSD: apropos.c,v 1.30 2009/05/08 12:48:43 wiz Exp $ */

/*
 * Copyright (c) 1987, 1993, 1994
 *      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.
 */

#include <sys/cdefs.h>

#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1987, 1993, 1994\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)apropos.c   8.8 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: apropos.c,v 1.30 2009/05/08 12:48:43 wiz Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/queue.h>

#include <ctype.h>
#include <err.h>
#include <glob.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "manconf.h"            /* from ../man/ */
#include "pathnames.h"          /* from ../man/ */

static bool *found;
static bool foundman = false;

#define MAXLINELEN      8192            /* max line handled */

static void apropos(char **, const char *, bool, const char *, const char *);
static void lowstr(const char *, char *);
static bool match(const char *, const char *);
static void usage(void) __dead;

int
main(int argc, char *argv[])
{
        ENTRY *ep;
        TAG *tp;
        int ch, rv;
        char *conffile, *machine, **p, *p_augment, *p_path, *sflag;
        glob_t pg;

        conffile = NULL;
        p_augment = p_path = NULL;
        machine = sflag = NULL;
        while ((ch = getopt(argc, argv, "C:M:m:P:S:s:")) != -1) {
                switch (ch) {
                case 'C':
                        conffile = optarg;
                        break;
                case 'M':
                case 'P':               /* backward compatible */
                        p_path = optarg;
                        break;
                case 'm':
                        p_augment = optarg;
                        break;
                case 'S':
                        machine = optarg;
                        lowstr(machine, machine);
                        break;
                case 's':
                        sflag = optarg;
                        lowstr(sflag, sflag);
                        break;
                case '?':
                default:
                        usage();
                }
        }
        argv += optind;
        argc -= optind;

        if (argc < 1)
                usage();

        if ((found = malloc(argc * sizeof(*found))) == NULL)
                err(EXIT_FAILURE, "malloc");
        (void)memset(found, 0, argc * sizeof(*found));

        for (p = argv; *p; ++p)                 /* convert to lower-case */
                lowstr(*p, *p);

        if (p_augment)
                apropos(argv, p_augment, true, sflag, machine);
        if (p_path || (p_path = getenv("MANPATH")))
                apropos(argv, p_path, true, sflag, machine);
        else {
                config(conffile);
                tp = gettag("_whatdb", 1);
                if (!tp)
                        errx(EXIT_FAILURE, "malloc");
                TAILQ_FOREACH(ep, &tp->entrylist, q) {
                        if ((rv = glob(ep->s, GLOB_BRACE | GLOB_NOSORT, NULL,
                            &pg)) != 0) {
                                if (rv == GLOB_NOMATCH)
                                        continue;
                                else
                                        err(EXIT_FAILURE, "glob");
                        }
                        if (pg.gl_pathc)
                                for (p = pg.gl_pathv; *p; p++)
                                        apropos(argv, *p, false, sflag,
                                                machine);
                        globfree(&pg);
                }
        }

        if (!foundman)
                errx(EXIT_FAILURE, "no %s file found", _PATH_WHATIS);

        rv = 1;
        for (p = argv; *p; ++p)
                if (found[p - argv])
                        rv = 0;
                else
                        (void)printf("%s: nothing appropriate\n", *p);
        return rv;
}

static void
apropos(char **argv, const char *path, bool buildpath,
        const char *sflag, const char *machine)
{
        char *end, **p;
        const char *name;
        char buf[MAXLINELEN + 1];
        char hold[MAXPATHLEN + 1];
        char wbuf[MAXLINELEN + 1];
        size_t slen = 0, mlen = 0;

        if (sflag)
                slen = strlen(sflag);
        if (machine)
                mlen = strlen(machine);

        for (name = path; name; name = end) {   /* through name list */
                if ((end = strchr(name, ':')) != NULL)
                        *end++ = '\0';

                if (buildpath) {
                        (void)snprintf(hold, sizeof(hold), "%s/%s", name,
                                        _PATH_WHATIS);
                        name = hold;
                }

                if (!freopen(name, "r", stdin))
                        continue;

                foundman = true;

                /* for each file found */
                while (fgets(buf, (int)sizeof(buf), stdin)) {
                        if (!strchr(buf, '\n')) {
                                warnx("%s: line too long", name);
                                continue;
                        }
                        lowstr(buf, wbuf);
                        if (machine) {
                                if ((strncmp(wbuf, machine, mlen) != 0) ||
                                    strlen(wbuf) <= mlen || wbuf[mlen] != '/')
                                        continue;
                        }
                        if (sflag) {
                                char *s = strchr(wbuf, '(');

                                if (!s)
                                        continue;
                                if (strncmp(s+1, sflag, slen) != 0)
                                        continue;
                        }
                        for (p = argv; *p; ++p) {
                                if (match(wbuf, *p)) {
                                        (void)printf("%s", buf);
                                        found[p - argv] = true;

                                        /* only print line once */
                                        while (*++p)
                                                if (match(wbuf, *p))
                                                        found[p - argv] = true;
                                        break;
                                }
                        }
                }
        }
}

/*
 * match --
 *      match anywhere the string appears
 */
static bool
match(const char *bp, const char *str)
{
        size_t len;
        char test;

        if (!*bp)
                return false;
        /* backward compatible: everything matches empty string */
        if (!*str)
                return true;
        for (test = *str++, len = strlen(str); *bp;)
                if (test == *bp++ && !strncmp(bp, str, len))
                        return true;
        return false;
}

/*
 * lowstr --
 *      convert a string to lower case
 */
static void
lowstr(const char *from, char *to)
{
        char ch;

        while ((ch = *from++) && ch != '\n')
                *to++ = tolower((unsigned char)ch);
        *to = '\0';
}

/*
 * usage --
 *      print usage message and die
 */
__dead
static void
usage(void)
{

        (void)fprintf(stderr,
            "usage: %s [-C file] [-M path] [-m path] "
            "[-S subsection] [-s section]\n"
            "       keyword ...\n",
            getprogname());
        exit(1);
}