WP-CLI: Remove all media in the database that isn't on the filesystem.

wpcli_remove_media_not_fs_files

wp db query "SELECT post_id, meta_value FROM wp_postmeta WHERE meta_key='_wp_attached_file'" --skip-column-names | \
    paste -s -d '\n' - | \
    xargs -n 2 bash -c '\
        FILE=wp-content/uploads/$2; \
        [[ ! -f ${FILE} ]] && echo $1; \
    ' argv0 | \
    sed -e 'H;${x;s/\n/,/g;s/^,//;p;};d' |
    xargs -i bash -c 'wp db query " \
        DELETE p, pm, tr \
        FROM wp_posts p \
        LEFT JOIN wp_postmeta pm ON ( p.ID = pm.post_id ) \
        LEFT JOIN wp_term_relationships tr ON ( p.ID = tr.object_id ) \
        WHERE p.ID IN ({}) \
    "'