missing man page

No man page found for cat.1%20/home/marcos/Evidencias/Bulk_20170518/domain_histogram.txt%20%7C%20grep%20-Eo%20%22%28http%7Chttps%7Cwww%29%3A//%5Ba-zA-Z0-9./%3F%3D_-%5D%2A%22%20%7C%20plan9-sort.