What is meaning of -vvv option in cURL request

问题

According to cURL documentation http://curl.haxx.se/docs/manpage.html

-v, --verbose

Makes the fetching more verbose/talkative.

But I came across

curl -vvv -u name@foo.com:password http://www.example.com 

What is the difference between -v and -vvv?

回答1:

tl;dr: there is no difference between -v and -vvv.

Specifying -v multiple times usually means to increase verbosity accordingly.

This is true, e.g for a software like memcached:

-v            verbose (print errors/warnings while in event loop)
-vv           very verbose (also print client commands/reponses)
-vvv          extremely verbose (also print internal state transitions)

(behind the scenes the options parser accumulates the level of verbosity).

But with curl command-line tool this is not the case. As you can see from tool_getparam.c, passing -v simply toggles the so-called trace type to TRACE_PLAIN. Passing -vv or -vvv does the same.

回答2:

Specifying -v multiple times usually means to increase verbosity accordingly. So in this case you'd expect a very verbose output (-v specified three times).

来源：https://stackoverflow.com/questions/24402473/what-is-meaning-of-vvv-option-in-curl-request