Composer installation -sS or -s

Question

On the webiste of Composer we can see this command :

curl -sS https://getcomposer.org/installer | php

What is the option -sS ?

Because i also see this solution on another tutorial :

curl -s https://getcomposer.org/installer | php

Answer 1

It depends what you want to do. From the curl manpage we can see that -s means "silent mode":

-s, --silent

Silent or quiet mode. Don't show progress meter or error messages. Makes Curl mute. It will still output the data you ask for, potentially even to the terminal/stdout unless you redirect it.

and that -S means to show errors:

-S, --show-error

When used with -s it makes curl show an error message if it fails.

Personally, I would use -sS.