**Example 1: To list the registered task definitions** The following ``list-task-definitions`` example lists all of the registered task definitions. :: aws ecs list-task-definitions Output:: { "taskDefinitionArns": [ "arn:aws:ecs:us-west-2:123456789012:task-definition/sleep300:2", "arn:aws:ecs:us-west-2:123456789012:task-definition/sleep360:1", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:3", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:4", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:5", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:6" ] } **Example 2: To list the registered task definitions in a family** The following `list-task-definitions` example lists the task definition revisions of a specified family. :: aws ecs list-task-definitions --family-prefix wordpress Output:: { "taskDefinitionArns": [ "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:3", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:4", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:5", "arn:aws:ecs:us-west-2:123456789012:task-definition/wordpress:6" ] } For more information, see `Amazon ECS Task Definitions `_ in the *Amazon ECS Developer Guide*.