输入该命令后会列出docker工具的“镜像管理”的相关命令。具体如： Commands: build：Build an image from a Dockerfile history：Show the history of an image import：Import the contents from a tarball to create a filesystem image inspect：Display detailed information on one or more images load：Load an image from a tar archive or STDIN ls：List images prune：Remove unused images pull：Download an image from a registry push：Upload an image to a registry rm：Remove one or more images save：Save one or more images to a tar archive (streamed to STDOUT by default) tag：Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
Run ‘docker image COMMAND --help’ for more information on a command.
