--out-null is #curl's 270th command line option.

Discard all response output of a transfer silently. This is the more efficient
and portable version of

curl host.example -o /dev/null

The transfer is done in full, all data is received and checked, but the bytes are not written anywhere. --out-null is associated with a single URL. Use it once per URL when you use several URLs in a command line.

#curl