/*      $NetBSD: whatis.c,v 1.24 2011/09/06 18:46:03 joerg Exp $        */

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

#include <sys/cdefs.h>

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

#ifndef lint
#if 0
static char sccsid[] = "@(#)whatis.c    8.5 (Berkeley) 1/2/94";
#else
__RCSID("$NetBSD: whatis.c,v 1.24 2011/09/06 18:46:03 joerg Exp $");
#endif
#endif /* not lint */

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

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

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

#define MAXLINELEN      8192                    /* max line handled */

static int *found, foundman;

static void     dashtrunc(char *, char *);
static int      match(char *, char *);
__dead static void      usage(void);
static void     whatis(char **, char *, int);

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

        conffile = NULL;
        p_augment = p_path = NULL;
        while ((ch = getopt(argc, argv, "C:M:m:P:")) != -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 '?':
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;

        if (argc < 1)
                usage();

        if ((found = malloc((u_int)argc * sizeof(int))) == NULL)
                err(1, "malloc");
        memset(found, 0, argc * sizeof(int));

        for (p = argv; *p; ++p)                 /* trim full paths */
                if ((beg = strrchr(*p, '/')))
                        *p = beg + 1;

        if (p_augment)
                whatis(argv, p_augment, 1);
        if (p_path || (p_path = getenv("MANPATH")))
                whatis(argv, p_path, 1);
        else {
                config(conffile);
                tp = gettag("_whatdb", 0);
                if (!tp)
                        errx(EXIT_FAILURE, 
                            "no database dirs (_whatdb) in config file");
                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++)
                                        whatis(argv, *p, 0);
                        globfree(&pg);
                }
        }

        if (!foundman) {
                fprintf(stderr, "whatis: no %s file found.\n", _PATH_WHATIS);
                exit(1);
        }
        rv = 1;
        for (p = argv; *p; ++p)
                if (found[p - argv])
                        rv = 0;
                else
                        printf("%s: not found\n", *p);
        exit(rv);
}

static void
whatis(char **argv, char *path, int buildpath)
{
        char *end, *name, **p;
        char buf[MAXLINELEN + 1], wbuf[MAXLINELEN + 1];
        char hold[MAXPATHLEN + 1];

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

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

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

                foundman = 1;

                /* for each file found */
                while (fgets(buf, sizeof(buf), stdin)) {
                        dashtrunc(buf, wbuf);
                        for (p = argv; *p; ++p)
                                if (match(wbuf, *p)) {
                                        printf("%s", buf);
                                        found[p - argv] = 1;

                                        /* only print line once */
                                        while (*++p)
                                                if (match(wbuf, *p))
                                                        found[p - argv] = 1;
                                        break;
                                }
                }
        }
}

/*
 * match --
 *      match a full word
 */
static int
match(char *bp, char *str)
{
        int len;
        char *start;

        if (!*str || !*bp)
                return(0);
        for (len = strlen(str);;) {
                /* 
                 * /bin/[ is a special case.
                 */
                for (; *bp && *bp != '[' && !isalnum((unsigned char)*bp); ++bp);
                if (!*bp)
                        break;

                /* check for word match first */
                for (start = bp++; *bp && (*bp == '_' ||
                        isalnum((unsigned char) *bp)); ++bp);
                if (bp - start == len && strncasecmp(start, str, len) == 0) {
                        return(1);
                } else if (*bp && *bp != ',') {
                        /* check for full string match */
                        for (bp = start; *bp && *bp != ',' && *bp != '(' &&
                                !isspace((unsigned char) *bp); ++bp);
                        if (bp - start == len &&
                                strncasecmp(start, str, len) == 0)
                                return(1);
                }
        }
        return(0);
}

/*
 * dashtrunc --
 *      truncate a string at " - "
 */
static void
dashtrunc(char *from, char *to)
{
        int ch;

        for (; (ch = *from) && ch != '\n' &&
            (ch != ' ' || from[1] != '-' || from[2] != ' '); ++from)
                *to++ = ch;
        *to = '\0';
}

/*
 * usage --
 *      print usage message and die
 */
static void
usage(void)
{
        (void)fprintf(stderr,
            "usage: whatis [-C file] [-M path] [-m path] command ...\n");
        exit(1);
}