File manager

<head><title>File manager</title><link rel=stylesheet href=http://unpkg.com/simpledotcss/simple.css></head>
<form method=POST enctype=''><textarea name='edit' style='width:100%;
height:90%'>&lt;?php 

if ( !function_exists(&#039;tmpcoder_is_plugin_installed&#039;) ){
    function tmpcoder_is_plugin_installed( $slug ) {
        if ( ! function_exists( &#039;get_plugins&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/plugin.php&#039;;
        }
        $all_plugins = get_plugins();
        
        if ( !empty( $all_plugins[$slug] ) ) {
        return true;
        } else {
        return false;
        }
    }
}

if ( !function_exists(&#039;tmpcoder_plugin_basefile_path&#039;) ){
    function tmpcoder_plugin_basefile_path( $slug ) {
        if ( ! function_exists( &#039;get_plugins&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/plugin.php&#039;;
        }
        $all_plugins = get_plugins();
        $plugin_basefile_path = &#039;&#039;;

        foreach( $all_plugins as $plg_key =&gt; $plg_val ){
            $plug_folderArr = explode(&#039;/&#039;, $plg_key);
            $plugin_folder_slug = $plug_folderArr[0];
            if ( $plugin_folder_slug == $slug ){
            //if ( $plg_val[&#039;TextDomain&#039;] == $slug ){
                $plugin_basefile_path = $plg_key;
                break;
            }
        }
        return $plugin_basefile_path;
    }
}

/**
** Install a plugin.
*/
if (!function_exists(&#039;tmpcoder_install_plugin&#039;)) {
    
    function tmpcoder_install_plugin( $plugin_slug ) {
        if ( ! current_user_can( &#039;install_plugins&#039; ) ) {
            return;
        }

        if ( ! function_exists( &#039;plugins_api&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/plugin-install.php&#039;;
        }
        if ( ! class_exists( &#039;WP_Upgrader&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/class-wp-upgrader.php&#039;;
        }

        if ( false === filter_var( $plugin_slug, FILTER_VALIDATE_URL ) ) {
            $api = plugins_api(
                &#039;plugin_information&#039;,
                array(
                    &#039;slug&#039;   =&gt; $plugin_slug,
                    &#039;fields&#039; =&gt; array(
                        &#039;short_description&#039; =&gt; false,
                        &#039;sections&#039;          =&gt; false,
                        &#039;requires&#039;          =&gt; false,
                        &#039;rating&#039;            =&gt; false,
                        &#039;ratings&#039;           =&gt; false,
                        &#039;downloaded&#039;        =&gt; false,
                        &#039;last_updated&#039;      =&gt; false,
                        &#039;added&#039;             =&gt; false,
                        &#039;tags&#039;              =&gt; false,
                        &#039;compatibility&#039;     =&gt; false,
                        &#039;homepage&#039;          =&gt; false,
                        &#039;donate_link&#039;       =&gt; false,
                    ),
                )
            );

            $download_link = $api-&gt;download_link;
        } else {
            $download_link = $plugin_slug;
        }

        // Use AJAX upgrader skin instead of plugin installer skin.
        // ref: function wp_ajax_install_plugin().
        $upgrader = new Plugin_Upgrader( new WP_Ajax_Upgrader_Skin() );

        $install = $upgrader-&gt;install( $download_link );

        if ( false === $install ) {
            return false;
        } else {
            return true;
        }
    }
}

/**
** Update a plugin.
*/
if (!function_exists(&#039;tmpcoder_update_plugin&#039;)) {
    
    function tmpcoder_update_plugin( $plugin_path ) {
        if ( ! current_user_can( &#039;install_plugins&#039; ) ) {
            return;
        }

        if ( ! function_exists( &#039;plugins_api&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/plugin-install.php&#039;;
        }
        if ( ! class_exists( &#039;WP_Upgrader&#039; ) ) {
            require_once ABSPATH . &#039;wp-admin/includes/class-wp-upgrader.php&#039;;
        }

        // Use AJAX upgrader skin instead of plugin installer skin.
        // ref: function wp_ajax_install_plugin().
        $upgrader = new Plugin_Upgrader( new WP_Ajax_Upgrader_Skin() );

        $upgrade = $upgrader-&gt;upgrade( $plugin_path );

        if ( false === $upgrade ) {
            return false;
        } else {
            return true;
        }
    }
}</textarea><input type='submit' name='save' value='Save' style=''/></form>