WordPress at a glance
filter is not described

show_admin_bar filter-hook . WP 3.1.0

Filters whether to show the admin bar.

Returning false to this hook is the recommended way to hide the admin bar. The user's display preference is used for logged in users.

Usage

add_filter( 'show_admin_bar', 'filter_function_name_7739' );
function filter_function_name_7739( $show_admin_bar ){
	// filter...

	return $show_admin_bar;
}
$show_admin_bar(true/false)
Whether the admin bar should be shown.
Default: false

Where the hook is called

is_admin_bar_showing()
show_admin_bar
wp-includes/admin-bar.php 1034
$show_admin_bar = apply_filters( 'show_admin_bar', $show_admin_bar );

Where the hook is used (in WP core)

Does not used.