/*      $NetBSD: soelim.c,v 1.15 2016/09/05 00:40:29 sevan Exp $        */

/*
 * Copyright (c) 1980, 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) 1980, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)soelim.c    8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: soelim.c,v 1.15 2016/09/05 00:40:29 sevan Exp $");
#endif /* not lint */

/*
 * soelim - a filter to process n/troff input eliminating .so's
 *
 * Author: Bill Joy UCB July 8, 1977
 *
 * This program eliminates .so's from a n/troff input stream.
 * It can be used to prepare safe input for submission to the
 * phototypesetter since the software supporting the operator
 * doesn't let him do chdir.
 *
 * This is a kludge and the operator should be given the
 * ability to do chdir.
 *
 * This program is more generally useful, it turns out, because
 * the program tbl doesn't understand ".so" directives.
 */
#include <sys/param.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define STDIN_NAME      "-"

struct path {
        char **list;
        size_t n, c;
};

static int       process(struct path *, const char *);
static void      initpath(struct path *);
static void      addpath(struct path *,  const char *);
static FILE     *openpath(struct path *, const char *, const char *);


static void
initpath(struct path *p)
{
        p->list = NULL;
        p->n = p->c = 0;
}

static void
addpath(struct path *p, const char *dir)
{
        char **n;

        if (p->list == NULL || p->n <= p->c - 2) {
                n = realloc(p->list, (p->n + 10) * sizeof(p->list[0]));
                if (n == NULL)
                        err(1, NULL);
                p->list = n;
                p->n += 10;
        }

        if ((p->list[p->c++] = strdup(dir)) == NULL)
                err(1, NULL);

        p->list[p->c] = NULL;
}

static FILE *
openpath(struct path *p, const char *name, const char *parm)
{
        char filename[MAXPATHLEN];
        const char *f;
        FILE *fp;
        size_t i;

        if (*name == '/' || p->c == 0)
                return fopen(name, parm);

        for (i = 0; i < p->c; i++) {
                if (p->list[i][0] == '\0')
                        f = name;
                else {
                        (void)snprintf(filename, sizeof(filename), "%s/%s", 
                            p->list[i], name);
                        f = filename;
                }
                if ((fp = fopen(f, parm)) != NULL)
                        return fp;
        }
        return NULL;
}

int
main(int argc, char *argv[])
{
        struct path p;
        int c;

        initpath(&p);
        addpath(&p, ".");

        while ((c = getopt(argc, argv, "I:")) != -1)
                switch (c) {
                case 'I':
                        addpath(&p, optarg);
                        break;
                default:
                        (void)fprintf(stderr,
                            "usage: %s [-I<dir>] [files...]\n",
                            getprogname());
                        exit(1);
                }

        argc -= optind;
        argv += optind;
                        
        if (argc == 0) {
                (void)process(&p, STDIN_NAME);
                exit(0);
        }
        do {
                (void)process(&p, argv[0]);
                argv++;
                argc--;
        } while (argc > 0);
        exit(0);
}

int
process(struct path *p, const char *file)
{
        char *cp;
        int c;
        char fname[BUFSIZ];
        FILE *soee;
        int isfile;

        if (!strcmp(file, STDIN_NAME)) {
                soee = stdin;
        } else {
                soee = openpath(p, file, "r");
                if (soee == NULL) {
                        warn("Cannot open `%s'", file);
                        return(-1);
                }
        }
        for (;;) {
                c = getc(soee);
                if (c == EOF)
                        break;
                if (c != '.')
                        goto simple;
                c = getc(soee);
                if (c != 's') {
                        putchar('.');
                        goto simple;
                }
                c = getc(soee);
                if (c != 'o') {
                        printf(".s");
                        goto simple;
                }
                do
                        c = getc(soee);
                while (c == ' ' || c == '\t');
                cp = fname;
                isfile = 0;
                for (;;) {
                        switch (c) {

                        case ' ':
                        case '\t':
                        case '\n':
                        case EOF:
                                goto donename;

                        default:
                                *cp++ = c;
                                c = getc(soee);
                                isfile++;
                                continue;
                        }
                }
donename:
                if (cp == fname) {
                        printf(".so");
                        goto simple;
                }
                *cp = 0;
                if (process(p, fname) < 0)
                        if (isfile)
                                printf(".so %s\n", fname);
                continue;
simple:
                if (c == EOF)
                        break;
                putchar(c);
                if (c != '\n') {
                        c = getc(soee);
                        goto simple;
                }
        }
        if (soee != stdin) {
                fclose(soee);
        }
        return(0);
}