/* $OpenBSD: cmd-show-environment.c,v 1.29 2025/04/09 06:27:43 nicm Exp $ */

/*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdlib.h>
#include <string.h>

#include "tmux.h"

/*
 * Show environment.
 */

static enum cmd_retval  cmd_show_environment_exec(struct cmd *,
                            struct cmdq_item *);

static char     *cmd_show_environment_escape(struct environ_entry *);
static void      cmd_show_environment_print(struct cmd *, struct cmdq_item *,
                     struct environ_entry *);

const struct cmd_entry cmd_show_environment_entry = {
        .name = "show-environment",
        .alias = "showenv",

        .args = { "hgst:", 0, 1, NULL },
        .usage = "[-hgs] " CMD_TARGET_SESSION_USAGE " [variable]",

        .target = { 't', CMD_FIND_SESSION, CMD_FIND_CANFAIL },

        .flags = CMD_AFTERHOOK,
        .exec = cmd_show_environment_exec
};

static char *
cmd_show_environment_escape(struct environ_entry *envent)
{
        const char      *value = envent->value;
        char             c, *out, *ret;

        out = ret = xmalloc(strlen(value) * 2 + 1); /* at most twice the size */
        while ((c = *value++) != '\0') {
                /* POSIX interprets $ ` " and \ in double quotes. */
                if (c == '$' || c == '`' || c == '"' || c == '\\')
                        *out++ = '\\';
                *out++ = c;
        }
        *out = '\0';

        return (ret);
}

static void
cmd_show_environment_print(struct cmd *self, struct cmdq_item *item,
    struct environ_entry *envent)
{
        struct args     *args = cmd_get_args(self);
        char            *escaped;

        if (!args_has(args, 'h') && (envent->flags & ENVIRON_HIDDEN))
                return;
        if (args_has(args, 'h') && (~envent->flags & ENVIRON_HIDDEN))
                return;

        if (!args_has(args, 's')) {
                if (envent->value != NULL)
                        cmdq_print(item, "%s=%s", envent->name, envent->value);
                else
                        cmdq_print(item, "-%s", envent->name);
                return;
        }

        if (envent->value != NULL) {
                escaped = cmd_show_environment_escape(envent);
                cmdq_print(item, "%s=\"%s\"; export %s;", envent->name, escaped,
                    envent->name);
                free(escaped);
        } else
                cmdq_print(item, "unset %s;", envent->name);
}

static enum cmd_retval
cmd_show_environment_exec(struct cmd *self, struct cmdq_item *item)
{
        struct args             *args = cmd_get_args(self);
        struct cmd_find_state   *target = cmdq_get_target(item);
        struct environ          *env;
        struct environ_entry    *envent;
        const char              *tflag, *name = args_string(args, 0);

        if ((tflag = args_get(args, 't')) != NULL) {
                if (target->s == NULL) {
                        cmdq_error(item, "no such session: %s", tflag);
                        return (CMD_RETURN_ERROR);
                }
        }

        if (args_has(args, 'g'))
                env = global_environ;
        else {
                if (target->s == NULL) {
                        tflag = args_get(args, 't');
                        if (tflag != NULL)
                                cmdq_error(item, "no such session: %s", tflag);
                        else
                                cmdq_error(item, "no current session");
                        return (CMD_RETURN_ERROR);
                }
                env = target->s->environ;
        }

        if (name != NULL) {
                envent = environ_find(env, name);
                if (envent == NULL) {
                        cmdq_error(item, "unknown variable: %s", name);
                        return (CMD_RETURN_ERROR);
                }
                cmd_show_environment_print(self, item, envent);
                return (CMD_RETURN_NORMAL);
        }

        envent = environ_first(env);
        while (envent != NULL) {
                cmd_show_environment_print(self, item, envent);
                envent = environ_next(envent);
        }
        return (CMD_RETURN_NORMAL);
}