/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1988, 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 <err.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

static void usage(void) __dead2;
static bool search(bool, bool, FILE *);

int
main(int argc, char *argv[])
{
        const char *file;
        FILE *in;
        bool found, qflag, sflag;
        int c;

        qflag = sflag = false;

        while ((c = getopt(argc, argv, "qs")) != -1) {
                switch (c) {
                case 'q':
                        qflag = true;
                        break;
                case 's':
                        sflag = true;
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        found = false;

        if (argc == 0) {
                if (search(sflag, qflag, stdin))
                        found = true;
        } else {
                while (argc--) {
                        file = *argv++;
                        in = fopen(file, "r");
                        if (in == NULL) {
                                if (!qflag)
                                        warn("%s", file);
                                continue;
                        }
                        if (!qflag)
                                printf("%s:\n", file);
                        if (search(sflag, qflag, in))
                                found = true;
                        fclose(in);
                }
        }
        exit(found ? 0 : 1);
}

static void
usage(void)
{
        fprintf(stderr, "usage: what [-qs] [file ...]\n");
        exit(1);
}

bool
search(bool one, bool quiet, FILE *in)
{
        bool found;
        int c;

        found = false;

        while ((c = getc(in)) != EOF) {
loop:           if (c != '@')
                        continue;
                if ((c = getc(in)) != '(')
                        goto loop;
                if ((c = getc(in)) != '#')
                        goto loop;
                if ((c = getc(in)) != ')')
                        goto loop;
                if (!quiet)
                        putchar('\t');
                while ((c = getc(in)) != EOF && c && c != '"' &&
                    c != '>' && c != '\\' && c != '\n')
                        putchar(c);
                putchar('\n');
                found = true;
                if (one)
                        break;
        }
        return (found);
}