Plugin for geany Save copy document

/*
 *      savecopy.c
 *
 *      https://www.geany.org/manual/reference/howto.html
 *
 *      yum install intltool geany-devel
 *
 *      gcc -c savecopy.c -fPIC `pkg-config --cflags geany`
 *      gcc savecopy.o -o savecopy.so -shared `pkg-config --libs geany`
 *
 *      Copyright 2018 Nikolay <xeritt(at)gmail.com>
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *      MA 02110-1301, USA.
 */

#include <geanyplugin.h>
static void write_data(const gchar *filename, const gchar *data){
    gint error_nr = utils_write_file(filename, data);
    gchar *utf8_filename = utils_get_utf8_from_locale(filename);

    if (error_nr == 0)
        ui_set_statusbar(TRUE, _("Document successfully exported as '%s'."), utf8_filename);
    else
        ui_set_statusbar(TRUE, _("File '%s' could not be written (%s)."),
            utf8_filename, g_strerror(error_nr));

    g_free(utf8_filename);
}

static void item_activate_cb(GtkMenuItem *menuitem, gpointer user_data){
    GeanyDocument *doc;
    doc = document_get_current();

    gint doc_len, i;
    gchar c, c_next;

    doc_len = sci_get_length(doc->editor->sci);
    GString *body;
    body = g_string_new("");

    char new_name[doc_len];
    sprintf(new_name, "%s_copy", doc->file_name);
    for (i = 0; i < doc_len; i++){
        c = sci_get_char_at(doc->editor->sci, i);
        g_string_append_c(body, c);
    }
    write_data(new_name, body->str);
    g_string_free(body, TRUE);
}

static gboolean save_init(GeanyPlugin *plugin, gpointer pdata){
    GtkWidget *main_menu_item;
    // Create a new menu item and show it
    main_menu_item = gtk_menu_item_new_with_mnemonic("Save copy");
    gtk_widget_show(main_menu_item);
    gtk_container_add(GTK_CONTAINER(plugin->geany_data->main_widgets->tools_menu),
            main_menu_item);
    g_signal_connect(main_menu_item, "activate",
            G_CALLBACK(item_activate_cb), NULL);
    geany_plugin_set_data(plugin, main_menu_item, NULL);
    return TRUE;
}
static void save_cleanup(GeanyPlugin *plugin, gpointer pdata)
{
    GtkWidget *main_menu_item = (GtkWidget *) pdata;
    gtk_widget_destroy(main_menu_item);
}
G_MODULE_EXPORT
void geany_load_module(GeanyPlugin *plugin)
{
    /* Step 1: Set metadata */
    plugin->info->name = "Save Copy";
    plugin->info->description = "Just save copy document";
    plugin->info->version = "1.0";
    plugin->info->author = "Nikolay <xeritt@gmail.com>";
    /* Step 2: Set functions */
    plugin->funcs->init = save_init;
    plugin->funcs->cleanup = save_cleanup;
    /* Step 3: Register! */
    GEANY_PLUGIN_REGISTER(plugin, 225);
    /* alternatively:
    GEANY_PLUGIN_REGISTER_FULL(plugin, 225, data, free_func); */
}