问题
Thanks please anyone suggest me what i am doing wrong in installation?enter image description here
回答1:
the problem first is to properly clean out your 'old' PHP based install -> Remove composer - but there are a number of answers posted there. Once you've done that, I would do an npm uninstall -g composer-cli etc etc then follow the doc link you referred to earlier.
Failing that, create a new user (or new environment) that does not have a prior footprint of your 'old' Composer PHP environment. Composer (CLI, Playground etc) should install quite happily once that is achieved per prereqs and main install docs here
来源：https://stackoverflow.com/questions/50328871/composer-playground-command-not-found-on-ubuntu-16-04