由curl手册页指定：
--cacert <CA certificate>
(TLS) Tells curl to use the specified certificate file to verify the peer. The file may contain multiple CA certificates. The certifi-
cate(s) must be in PEM format. Normally curl is built to use a default file for this, so this option is typically used to alter that
default file.
curl recognizes the environment variable named 'CURL_CA_BUNDLE' if it is set, and uses the given path as a path to a CA cert bundle.
This option overrides that variable.
The windows version of curl will automatically look for a CA certs file named 'curl-ca-bundle.crt', either in the same directory as
curl.exe, or in the Current Working Directory, or in any folder along your PATH.
If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module (libnsspem.so) needs to be available for this option to work
properly.
(iOS and macOS only) If curl is built against Secure Transport, then this option is supported for backward compatibility with other SSL
engines, but it should not be set. If the option is not set, then curl will use the certificates in the system and user Keychain to ver-
ify the peer, which is the preferred method of verifying the peer's certificate chain.
If this option is used several times, the last one will be used.
我想知道如何实际显示当前设置的证书的位置或内容或。