/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1988, 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.
 *
 * @(#)env.c    8.3 (Berkeley) 4/2/94
 * $FreeBSD: head/usr.bin/env/env.c 326025 2017-11-20 19:49:47Z pfg $
 */

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

#include "envopts.h"

extern char **environ;

int      env_verbosity;

static void usage(void);

int
main(int argc, char **argv)
{
        char *altpath, **ep, *p, **parg;
        char *cleanenv[1];
        int ch, want_clear;
        int rtrn;

        altpath = NULL;
        want_clear = 0;
        while ((ch = getopt(argc, argv, "iP:S:u:v-")) != -1)
                switch(ch) {
                case '-':
                case 'i':
                        want_clear = 1;
                        break;
                case 'P':
                        altpath = strdup(optarg);
                        break;
                case 'S':
                        /*
                         * The -S option, for "split string on spaces, with
                         * support for some simple substitutions"...
                         */
                        split_spaces(optarg, &optind, &argc, &argv);
                        break;
                case 'u':
                        if (env_verbosity)
                                fprintf(stderr, "#env unset:\t%s\n", optarg);
                        rtrn = unsetenv(optarg);
                        if (rtrn == -1)
                                err(EXIT_FAILURE, "unsetenv %s", optarg);
                        break;
                case 'v':
                        env_verbosity++;
                        if (env_verbosity > 1)
                                fprintf(stderr, "#env verbosity now at %d\n",
                                    env_verbosity);
                        break;
                case '?':
                default:
                        usage();
                }
        if (want_clear) {
                environ = cleanenv;
                cleanenv[0] = NULL;
                if (env_verbosity)
                        fprintf(stderr, "#env clearing environ\n");
        }
        for (argv += optind; *argv && (p = strchr(*argv, '=')); ++argv) {
                if (env_verbosity)
                        fprintf(stderr, "#env setenv:\t%s\n", *argv);
                *p = '\0';
                rtrn = setenv(*argv, p + 1, 1);
                *p = '=';
                if (rtrn == -1)
                        err(EXIT_FAILURE, "setenv %s", *argv);
        }
        if (*argv) {
                if (altpath)
                        search_paths(altpath, argv);
                if (env_verbosity) {
                        fprintf(stderr, "#env executing:\t%s\n", *argv);
                        for (parg = argv, argc = 0; *parg; parg++, argc++)
                                fprintf(stderr, "#env    arg[%d]=\t'%s'\n",
                                    argc, *parg);
                        if (env_verbosity > 1)
                                sleep(1);
                }
                execvp(*argv, argv);
                err(errno == ENOENT ? 127 : 126, "%s", *argv);
        }
        for (ep = environ; *ep; ep++)
                printf("%s\n", *ep);
        exit(0);
}

static void
usage(void)
{
        fprintf(stderr,
            "usage: env [-iv] [-P utilpath] [-S string] [-u name]\n"
            "           [name=value ...] [utility [argument ...]]\n");
        exit(1);
}