Prince Networking
Prince can process local files or fetch them from remote locations. To do this, a full URL needs to be provided, including the protocol.
prince http://example.com/path/file.html
-o out.pdf
Authentication
If authentication is required for the URL, the credentials can be passed by means of the --auth-user
and --auth-password
command-line options. A more cautious way is to add the --auth-server
option, which sends username and password credentials to the specified server only - the default is to send them to any server which challenges for authentication. The option --auth-scheme
sends username and password credentials only for requests with the given scheme, either HTTP or HTTPS, while --auth-method
specifies a comma separated list of HTTP authentication methods to enable. Valid entries are: basic
, digest
, ntlm
and negotiate
.
A shorthand command-line option for authentication is --auth
, which specifies a URL with credentials for HTTP authentication: [SCHEME:]//USER:PASS@HOST[:PORT]
. Unlike the preceding options, it may be used multiple times. The username and password must be percent-encoded.
The advanced command-line option --no-auth-preemptive
instructs Prince not to send credentials to named servers until an authentication challenge is received. When multiple authentication methods are enabled, an initial request may be required to discover the methods supported by the remote site.
Cookies
If cookies are required, the --cookie
command-line option can be used to set a value for the Set-Cookie HTTP header value. The option may be used multiple times. Alternatively, the option --cookiejar
specifies a file containing HTTP cookies.
SSL
The command-line option --ssl-cacert
specifies an SSL certificate file, while the option --ssl-capath
is used to specify an SSL certificate directory.
The command-line option --ssl-version
sets the minimum version of SSL to allow. It may be one of: default
, tlsv1
, tlsv1.0
, tlsv1.1
, tlsv1.2
or tlsv1.3
. The value default
lets libcurl choose. The option --insecure
disables SSL verification. Please note that using this option is not recommended!
Prince makes use of the libcurl library to process network locations - see Acknowledgments. Please note that command-line options are passed to curl as-is. On some systems curl might use a library other than OpenSSL to handle SSL - in those cases the SSL-related command-line options might behave in a slightly different way. In case of doubt, please check your own curl documentation.
Client Certificates
Client certificates are supported on Linux with several command-line options. The --ssl-cert
option specifies an SSL client certificate file, while the --ssl-cert-type
option defines the SSL client certificate file type (PEM, DER) - the default is PEM. The option --ssl-key
specifies an SSL private key file and --ssl-key-type
is used to define the SSL private key file type (PEM, DER) - the default is PEM. Last but not least, --ssl-key-password
indicates the passphrase for the private key.
On MacOS, the command-line option --ssl-cert
specifies a PKCS#12 file containing a client certificate and private key. The options --ssl-cert-type
, --ssl-key
and --ssl-key-password
are not available.
Client certificates are not supported on Windows.
Miscellaneous
If an HTTP proxy server is required, it can be specified with the --http-proxy
command-line option.
Please note that since Prince uses curl for loading resources from HTTP URLs, it is possible to use curl-supported environment variables (such as e.g. http_proxy
and no_proxy
) to fine-tune the proxy rules. In this case it is not necessary to specify the command-line option - the proxy rules are provided through the environment variables. See this forum post for more details.
The option --http-timeout
can be used to define the HTTP timeout in seconds, which can be useful for slow servers.
Prince can also disable downloading multiple HTTP resources at once with the --no-parallel-downloads
command-line option.