CompTIA Linux+ XK0-006 (V8) Practice Question

The combination of options -I, -s, -o /dev/null, -w "%{http_code}\n", and -f delivers exactly what the script needs. -I performs a true HEAD request, so no body is transferred. -s suppresses the progress meter, and -o /dev/null discards anything that might still be written to standard output. -w prints just the value of the http_code variable, giving a clean numeric status line. Finally, -f makes curl exit with status 22 when the response code is 400 or higher, so the calling script can treat any 4xx/5xx reply as a failure.

The other commands miss at least one requirement:

• The version that omits -I still issues a GET and therefore transfers the response body.
• The variant that leaves out -o /dev/null lets the response headers appear on stdout, so the output is not limited to the status code.
• Using -X HEAD only changes the request word and does not behave like a real HEAD request; it can hang if the server sets an inappropriate Content-Length. Therefore it is not reliable for scripted checks.