Struct curl::easy::Easy [−] [src]

pub struct Easy { /* fields omitted */ }

Raw bindings to a libcurl "easy session".

This type corresponds to the CURL type in libcurl, and is probably what you want for just sending off a simple HTTP request and fetching a response. Each easy handle can be thought of as a large builder before calling the final perform function.

There are many many configuration options for each Easy handle, and they should all have their own documentation indicating what it affects and how it interacts with other options. Some implementations of libcurl can use this handle to interact with many different protocols, although by default this crate only guarantees the HTTP/HTTPS protocols working.

Note that almost all methods on this structure which configure various properties return a Result. This is largely used to detect whether the underlying implementation of libcurl actually implements the option being requested. If you're linked to a version of libcurl which doesn't support the option, then an error will be returned. Some options also perform some validation when they're set, and the error is returned through this vector.

Examples

Creating a handle which can be used later

use curl::easy::Easy;

let handle = Easy::new();

Send an HTTP request, writing the response to stdout.

use std::io::{stdout, Write};

use curl::easy::Easy;

let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();
handle.write_function(|data| {
    Ok(stdout().write(data).unwrap())
}).unwrap();
handle.perform().unwrap();

Collect all output of an HTTP request to a vector.

use curl::easy::Easy;

let mut data = Vec::new();
let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();
{
    let mut transfer = handle.transfer();
    transfer.write_function(|new_data| {
        data.extend_from_slice(new_data);
        Ok(new_data.len())
    }).unwrap();
    transfer.perform().unwrap();
}
println!("{:?}", data);

More examples of various properties of an HTTP request can be found on the specific methods as well.

Methods

impl Easy
[src]

Creates a new "easy" handle which is the core of almost all operations in libcurl.

To use a handle, applications typically configure a number of options followed by a call to perform. Options are preserved across calls to perform and need to be reset manually (or via the reset method) if this is not desired.

Configures this handle to have verbose output to help debug protocol information.

By default output goes to stderr, but the stderr function on this type can configure that. You can also use the debug_function method to get all protocol data sent and received.

By default, this option is false.

Indicates whether header information is streamed to the output body of this request.

This option is only relevant for protocols which have header metadata (like http or ftp). It's not generally possible to extract headers from the body if using this method, that use case should be intended for the header_function method.

To set HTTP headers, use the http_header method.

By default, this option is false and corresponds to CURLOPT_HEADER.

Indicates whether a progress meter will be shown for requests done with this handle.

This will also prevent the progress_function from being called.

By default this option is false and corresponds to CURLOPT_NOPROGRESS.

Inform libcurl whether or not it should install signal handlers or attempt to use signals to perform library functions.

If this option is disabled then timeouts during name resolution will not work unless libcurl is built against c-ares. Note that enabling this option, however, may not cause libcurl to work with multiple threads.

By default this option is false and corresponds to CURLOPT_NOSIGNAL. Note that this default is different than libcurl as it is intended that this library is threadsafe by default. See the libcurl docs for some more information.

Indicates whether multiple files will be transferred based on the file name pattern.

The last part of a filename uses fnmatch-like pattern matching.

By default this option is false and corresponds to CURLOPT_WILDCARDMATCH.

Set callback for writing received data.

This callback function gets called by libcurl as soon as there is data received that needs to be saved.

The callback function will be passed as much data as possible in all invokes, but you must not make any assumptions. It may be one byte, it may be thousands. If show_header is enabled, which makes header data get passed to the write callback, you can get up to CURL_MAX_HTTP_HEADER bytes of header data passed into it. This usually means 100K.

This function may be called with zero bytes data if the transferred file is empty.

The callback should return the number of bytes actually taken care of. If that amount differs from the amount passed to your callback function, it'll signal an error condition to the library. This will cause the transfer to get aborted and the libcurl function used will return an error with is_write_error.

If your callback function returns Err(WriteError::Pause) it will cause this transfer to become paused. See unpause_write for further details.

By default data is sent into the void, and this corresponds to the CURLOPT_WRITEFUNCTION and CURLOPT_WRITEDATA options.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using write_function to configure a callback that can reference stack-local data.

Examples

use std::io::{stdout, Write};
use curl::easy::Easy;

let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();
handle.write_function(|data| {
    Ok(stdout().write(data).unwrap())
}).unwrap();
handle.perform().unwrap();

Writing to a stack-local buffer

use std::io::{stdout, Write};
use curl::easy::Easy;

let mut buf = Vec::new();
let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();

let mut transfer = handle.transfer();
transfer.write_function(|data| {
    buf.extend_from_slice(data);
    Ok(data.len())
}).unwrap();
transfer.perform().unwrap();

Read callback for data uploads.

This callback function gets called by libcurl as soon as it needs to read data in order to send it to the peer - like if you ask it to upload or post data to the server.

Your function must then return the actual number of bytes that it stored in that memory area. Returning 0 will signal end-of-file to the library and cause it to stop the current transfer.

If you stop the current transfer by returning 0 "pre-maturely" (i.e before the server expected it, like when you've said you will upload N bytes and you upload less than N bytes), you may experience that the server "hangs" waiting for the rest of the data that won't come.

The read callback may return Err(ReadError::Abort) to stop the current operation immediately, resulting in a is_aborted_by_callback error code from the transfer.

The callback can return Err(ReadError::Pause) to cause reading from this connection to pause. See unpause_read for further details.

By default data not input, and this corresponds to the CURLOPT_READFUNCTION and CURLOPT_READDATA options.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using read_function to configure a callback that can reference stack-local data.

Examples

Read input from stdin

use std::io::{stdin, Read};
use curl::easy::Easy;

let mut handle = Easy::new();
handle.url("https://example.com/login").unwrap();
handle.read_function(|into| {
    Ok(stdin().read(into).unwrap())
}).unwrap();
handle.post(true).unwrap();
handle.perform().unwrap();

Reading from stack-local data:

use std::io::{stdin, Read};
use curl::easy::Easy;

let mut data_to_upload = &b"foobar"[..];
let mut handle = Easy::new();
handle.url("https://example.com/login").unwrap();
handle.post(true).unwrap();

let mut transfer = handle.transfer();
transfer.read_function(|into| {
    Ok(data_to_upload.read(into).unwrap())
}).unwrap();
transfer.perform().unwrap();

User callback for seeking in input stream.

This function gets called by libcurl to seek to a certain position in the input stream and can be used to fast forward a file in a resumed upload (instead of reading all uploaded bytes with the normal read function/callback). It is also called to rewind a stream when data has already been sent to the server and needs to be sent again. This may happen when doing a HTTP PUT or POST with a multi-pass authentication method, or when an existing HTTP connection is reused too late and the server closes the connection.

The callback function must return SeekResult::Ok on success, SeekResult::Fail to cause the upload operation to fail or SeekResult::CantSeek to indicate that while the seek failed, libcurl is free to work around the problem if possible. The latter can sometimes be done by instead reading from the input or similar.

By default data this option is not set, and this corresponds to the CURLOPT_SEEKFUNCTION and CURLOPT_SEEKDATA options.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using seek_function to configure a callback that can reference stack-local data.

Callback to progress meter function

This function gets called by libcurl instead of its internal equivalent with a frequent interval. While data is being transferred it will be called very frequently, and during slow periods like when nothing is being transferred it can slow down to about one call per second.

The callback gets told how much data libcurl will transfer and has transferred, in number of bytes. The first argument is the total number of bytes libcurl expects to download in this transfer. The second argument is the number of bytes downloaded so far. The third argument is the total number of bytes libcurl expects to upload in this transfer. The fourth argument is the number of bytes uploaded so far.

Unknown/unused argument values passed to the callback will be set to zero (like if you only download data, the upload size will remain 0). Many times the callback will be called one or more times first, before it knows the data sizes so a program must be made to handle that.

Returning false from this callback will cause libcurl to abort the transfer and return is_aborted_by_callback.

If you transfer data with the multi interface, this function will not be called during periods of idleness unless you call the appropriate libcurl function that performs transfers.

noprogress must be set to 0 to make this function actually get called.

By default this function calls an internal method and corresponds to CURLOPT_PROGRESSFUNCTION and CURLOPT_PROGRESSDATA.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using progress_function to configure a callback that can reference stack-local data.

Callback to SSL context

This callback function gets called by libcurl just before the initialization of an SSL connection after having processed all other SSL related options to give a last chance to an application to modify the behaviour of the SSL initialization. The ssl_ctx parameter is actually a pointer to the SSL library's SSL_CTX. If an error is returned from the callback no attempt to establish a connection is made and the perform operation will return the callback's error code.

This function will get called on all new connections made to a server, during the SSL negotiation. The SSL_CTX pointer will be a new one every time.

To use this properly, a non-trivial amount of knowledge of your SSL library is necessary. For example, you can use this function to call library-specific callbacks to add additional validation code for certificates, and even to change the actual URI of a HTTPS request.

By default this function calls an internal method and corresponds to CURLOPT_SSL_CTX_FUNCTION and CURLOPT_SSL_CTX_DATA.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using progress_function to configure a callback that can reference stack-local data.

Specify a debug callback

debug_function replaces the standard debug function used when verbose is in effect. This callback receives debug information, as specified in the type argument.

By default this option is not set and corresponds to the CURLOPT_DEBUGFUNCTION and CURLOPT_DEBUGDATA options.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using debug_function to configure a callback that can reference stack-local data.

Callback that receives header data

This function gets called by libcurl as soon as it has received header data. The header callback will be called once for each header and only complete header lines are passed on to the callback. Parsing headers is very easy using this. If this callback returns false it'll signal an error to the library. This will cause the transfer to get aborted and the libcurl function in progress will return is_write_error.

A complete HTTP header that is passed to this function can be up to CURL_MAX_HTTP_HEADER (100K) bytes.

It's important to note that the callback will be invoked for the headers of all responses received after initiating a request and not just the final response. This includes all responses which occur during authentication negotiation. If you need to operate on only the headers from the final response, you will need to collect headers in the callback yourself and use HTTP status lines, for example, to delimit response boundaries.

When a server sends a chunked encoded transfer, it may contain a trailer. That trailer is identical to a HTTP header and if such a trailer is received it is passed to the application using this callback as well. There are several ways to detect it being a trailer and not an ordinary header: 1) it comes after the response-body. 2) it comes after the final header line (CR LF) 3) a Trailer: header among the regular response-headers mention what header(s) to expect in the trailer.

For non-HTTP protocols like FTP, POP3, IMAP and SMTP this function will get called with the server responses to the commands that libcurl sends.

By default this option is not set and corresponds to the CURLOPT_HEADERFUNCTION and CURLOPT_HEADERDATA options.

Note that the lifetime bound on this function is 'static, but that is often too restrictive. To use stack data consider calling the transfer method and then using header_function to configure a callback that can reference stack-local data.

Examples

use std::str;

use curl::easy::Easy;

let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();
handle.header_function(|header| {
    print!("header: {}", str::from_utf8(header).unwrap());
    true
}).unwrap();
handle.perform().unwrap();

Collecting headers to a stack local vector

use std::str;

use curl::easy::Easy;

let mut headers = Vec::new();
let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();

{
    let mut transfer = handle.transfer();
    transfer.header_function(|header| {
        headers.push(str::from_utf8(header).unwrap().to_string());
        true
    }).unwrap();
    transfer.perform().unwrap();
}

println!("{:?}", headers);

Indicates whether this library will fail on HTTP response codes >= 400.

This method is not fail-safe especially when authentication is involved.

By default this option is false and corresponds to CURLOPT_FAILONERROR.

Provides the URL which this handle will work with.

The string provided must be URL-encoded with the format:

scheme://host:port/path

The syntax is not validated as part of this function and that is deferred until later.

By default this option is not set and perform will not work until it is set. This option corresponds to CURLOPT_URL.

Configures the port number to connect to, instead of the one specified in the URL or the default of the protocol.

Provide the URL of a proxy to use.

By default this option is not set and corresponds to CURLOPT_PROXY.

Provide port number the proxy is listening on.

By default this option is not set (the default port for the proxy protocol is used) and corresponds to CURLOPT_PROXYPORT.

Indicates the type of proxy being used.

By default this option is ProxyType::Http and corresponds to CURLOPT_PROXYTYPE.

Provide a list of hosts that should not be proxied to.

This string is a comma-separated list of hosts which should not use the proxy specified for connections. A single * character is also accepted as a wildcard for all hosts.

By default this option is not set and corresponds to CURLOPT_NOPROXY.

Inform curl whether it should tunnel all operations through the proxy.

This essentially means that a CONNECT is sent to the proxy for all outbound requests.

By default this option is false and corresponds to CURLOPT_HTTPPROXYTUNNEL.

Tell curl which interface to bind to for an outgoing network interface.

The interface name, IP address, or host name can be specified here.

By default this option is not set and corresponds to CURLOPT_INTERFACE.

Indicate which port should be bound to locally for this connection.

By default this option is 0 (any port) and corresponds to CURLOPT_LOCALPORT.

Indicates the number of attempts libcurl will perform to find a working port number.

By default this option is 1 and corresponds to CURLOPT_LOCALPORTRANGE.

Sets the timeout of how long name resolves will be kept in memory.

This is distinct from DNS TTL options and is entirely speculative.

By default this option is 60s and corresponds to CURLOPT_DNS_CACHE_TIMEOUT.

Specify the preferred receive buffer size, in bytes.

This is treated as a request, not an order, and the main point of this is that the write callback may get called more often with smaller chunks.

By default this option is the maximum write size and corresopnds to CURLOPT_BUFFERSIZE.

Configures whether the TCP_NODELAY option is set, or Nagle's algorithm is disabled.

The purpose of Nagle's algorithm is to minimize the number of small packet's on the network, and disabling this may be less efficient in some situations.

By default this option is false and corresponds to CURLOPT_TCP_NODELAY.

Configures the scope for local IPv6 addresses.

Sets the scope_id value to use when connecting to IPv6 or link-local addresses.

By default this value is 0 and corresponds to CURLOPT_ADDRESS_SCOPE

Configures the username to pass as authentication for this connection.

By default this value is not set and corresponds to CURLOPT_USERNAME.

Configures the password to pass as authentication for this connection.

By default this value is not set and corresponds to CURLOPT_PASSWORD.

Set HTTP server authentication methods to try

If more than one method is set, libcurl will first query the site to see which authentication methods it supports and then pick the best one you allow it to use. For some methods, this will induce an extra network round-trip. Set the actual name and password with the password and username methods.

For authentication with a proxy, see proxy_auth.

By default this value is basic and corresponds to CURLOPT_HTTPAUTH.

Configures the proxy username to pass as authentication for this connection.

By default this value is not set and corresponds to CURLOPT_PROXYUSERNAME.

Configures the proxy password to pass as authentication for this connection.

By default this value is not set and corresponds to CURLOPT_PROXYPASSWORD.

Set HTTP proxy authentication methods to try

If more than one method is set, libcurl will first query the site to see which authentication methods it supports and then pick the best one you allow it to use. For some methods, this will induce an extra network round-trip. Set the actual name and password with the proxy_password and proxy_username methods.

By default this value is basic and corresponds to CURLOPT_PROXYAUTH.

Enable .netrc parsing

By default the .netrc file is ignored and corresponds to CURL_NETRC_IGNORED.

Indicates whether the referer header is automatically updated

By default this option is false and corresponds to CURLOPT_AUTOREFERER.

Enables automatic decompression of HTTP downloads.

Sets the contents of the Accept-Encoding header sent in an HTTP request. This enables decoding of a response with Content-Encoding.

Currently supported encoding are identity, zlib, and gzip. A zero-length string passed in will send all accepted encodings.

By default this option is not set and corresponds to CURLOPT_ACCEPT_ENCODING.

Request the HTTP Transfer Encoding.

By default this option is false and corresponds to CURLOPT_TRANSFER_ENCODING.

Follow HTTP 3xx redirects.

Indicates whether any Location headers in the response should get followed.

By default this option is false and corresponds to CURLOPT_FOLLOWLOCATION.

Send credentials to hosts other than the first as well.

Sends username/password credentials even when the host changes as part of a redirect.

By default this option is false and corresponds to CURLOPT_UNRESTRICTED_AUTH.

Set the maximum number of redirects allowed.

A value of 0 will refuse any redirect.

By default this option is -1 (unlimited) and corresponds to CURLOPT_MAXREDIRS.

Make an HTTP PUT request.

By default this option is false and corresponds to CURLOPT_PUT.

Make an HTTP POST request.

This will also make the library use the Content-Type: application/x-www-form-urlencoded header.

POST data can be specified through post_fields or by specifying a read function.

By default this option is false and corresponds to CURLOPT_POST.

Configures the data that will be uploaded as part of a POST.

Note that the data is copied into this handle and if that's not desired then the read callbacks can be used instead.

By default this option is not set and corresponds to CURLOPT_COPYPOSTFIELDS.

Configures the size of data that's going to be uploaded as part of a POST operation.

This is called automaticsally as part of post_fields and should only be called if data is being provided in a read callback (and even then it's optional).

By default this option is not set and corresponds to CURLOPT_POSTFIELDSIZE_LARGE.

Tells libcurl you want a multipart/formdata HTTP POST to be made and you instruct what data to pass on to the server in the form argument.

By default this option is set to null and corresponds to CURLOPT_HTTPPOST.

Sets the HTTP referer header

By default this option is not set and corresponds to CURLOPT_REFERER.

Sets the HTTP user-agent header

By default this option is not set and corresponds to CURLOPT_USERAGENT.

Add some headers to this HTTP request.

If you add a header that is otherwise used internally, the value here takes precedence. If a header is added with no content (like Accept:) the internally the header will get disabled. To add a header with no content, use the form MyHeader; (not the trailing semicolon).

Headers must not be CRLF terminated. Many replaced headers have common shortcuts which should be prefered.

By default this option is not set and corresponds to CURLOPT_HTTPHEADER

Examples

use curl::easy::{Easy, List};

let mut list = List::new();
list.append("Foo: bar").unwrap();
list.append("Bar: baz").unwrap();

let mut handle = Easy::new();
handle.url("https://www.rust-lang.org/").unwrap();
handle.http_headers(list).unwrap();
handle.perform().unwrap();

Set the contents of the HTTP Cookie header.

Pass a string of the form name=contents for one cookie value or name1=val1; name2=val2 for multiple values.

Using this option multiple times will only make the latest string override the previous ones. This option will not enable the cookie engine, use cookie_file or cookie_jar to do that.

By default this option is not set and corresponds to CURLOPT_COOKIE.

Set the file name to read cookies from.

The cookie data can be in either the old Netscape / Mozilla cookie data format or just regular HTTP headers (Set-Cookie style) dumped to a file.

This also enables the cookie engine, making libcurl parse and send cookies on subsequent requests with this handle.

Given an empty or non-existing file or by passing the empty string ("") to this option, you can enable the cookie engine without reading any initial cookies.

If you use this option multiple times, you just add more files to read. Subsequent files will add more cookies.

By default this option is not set and corresponds to CURLOPT_COOKIEFILE.

Set the file name to store cookies to.

This will make libcurl write all internally known cookies to the file when this handle is dropped. If no cookies are known, no file will be created. Specify "-" as filename to instead have the cookies written to stdout. Using this option also enables cookies for this session, so if you for example follow a location it will make matching cookies get sent accordingly.

Note that libcurl doesn't read any cookies from the cookie jar. If you want to read cookies from a file, use cookie_file.

By default this option is not set and corresponds to CURLOPT_COOKIEJAR.

Start a new cookie session

Marks this as a new cookie "session". It will force libcurl to ignore all cookies it is about to load that are "session cookies" from the previous session. By default, libcurl always stores and loads all cookies, independent if they are session cookies or not. Session cookies are cookies without expiry date and they are meant to be alive and existing for this "session" only.

By default this option is false and corresponds to CURLOPT_COOKIESESSION.

Add to or manipulate cookies held in memory.

Such a cookie can be either a single line in Netscape / Mozilla format or just regular HTTP-style header (Set-Cookie: ...) format. This will also enable the cookie engine. This adds that single cookie to the internal cookie store.

Exercise caution if you are using this option and multiple transfers may occur. If you use the Set-Cookie format and don't specify a domain then the cookie is sent for any domain (even after redirects are followed) and cannot be modified by a server-set cookie. If a server sets a cookie of the same name (or maybe you've imported one) then both will be sent on a future transfer to that server, likely not what you intended. address these issues set a domain in Set-Cookie or use the Netscape format.

Additionally, there are commands available that perform actions if you pass in these exact strings:

  • "ALL" - erases all cookies held in memory
  • "SESS" - erases all session cookies held in memory
  • "FLUSH" - write all known cookies to the specified cookie jar
  • "RELOAD" - reread all cookies from the cookie file

By default this options corresponds to CURLOPT_COOKIELIST

Ask for a HTTP GET request.

By default this option is false and corresponds to CURLOPT_HTTPGET.

Ignore the content-length header.

By default this option is false and corresponds to CURLOPT_IGNORE_CONTENT_LENGTH.

Enable or disable HTTP content decoding.

By default this option is true and corresponds to CURLOPT_HTTP_CONTENT_DECODING.

Enable or disable HTTP transfer decoding.

By default this option is true and corresponds to CURLOPT_HTTP_TRANSFER_DECODING.

Indicates the range that this request should retrieve.

The string provided should be of the form N-M where either N or M can be left out. For HTTP transfers multiple ranges separated by commas are also accepted.

By default this option is not set and corresponds to CURLOPT_RANGE.

Set a point to resume transfer from

Specify the offset in bytes you want the transfer to start from.

By default this option is 0 and corresponds to CURLOPT_RESUME_FROM_LARGE.

Set a custom request string

Specifies that a custom request will be made (e.g. a custom HTTP method). This does not change how libcurl performs internally, just changes the string sent to the server.

By default this option is not set and corresponds to CURLOPT_CUSTOMREQUEST.

Get the modification time of the remote resource

If true, libcurl will attempt to get the modification time of the remote document in this operation. This requires that the remote server sends the time or replies to a time querying command. The filetime function can be used after a transfer to extract the received time (if any).

By default this option is false and corresponds to CURLOPT_FILETIME

Indicate whether to download the request without getting the body

This is useful, for example, for doing a HEAD request.

By default this option is false and corresponds to CURLOPT_NOBODY.

Set the size of the input file to send off.

By default this option is not set and corresponds to CURLOPT_INFILESIZE_LARGE.

Enable or disable data upload.

This means that a PUT request will be made for HTTP and probably wants to be combined with the read callback as well as the in_filesize method.

By default this option is false and corresponds to CURLOPT_UPLOAD.

Configure the maximum file size to download.

By default this option is not set and corresponds to CURLOPT_MAXFILESIZE_LARGE.

Selects a condition for a time request.

This value indicates how the time_value option is interpreted.

By default this option is not set and corresponds to CURLOPT_TIMECONDITION.

Sets the time value for a conditional request.

The value here should be the number of seconds elapsed since January 1, 1970. To pass how to interpret this value, use time_condition.

By default this option is not set and corresponds to CURLOPT_TIMEVALUE.

Set maximum time the request is allowed to take.

Normally, name lookups can take a considerable time and limiting operations to less than a few minutes risk aborting perfectly normal operations.

If libcurl is built to use the standard system name resolver, that portion of the transfer will still use full-second resolution for timeouts with a minimum timeout allowed of one second.

In unix-like systems, this might cause signals to be used unless nosignal is set.

Since this puts a hard limit for how long a request is allowed to take, it has limited use in dynamic use cases with varying transfer times. You are then advised to explore low_speed_limit, low_speed_time or using progress_function to implement your own timeout logic.

By default this option is not set and corresponds to CURLOPT_TIMEOUT_MS.

Set the low speed limit in bytes per second.

This specifies the average transfer speed in bytes per second that the transfer should be below during low_speed_time for libcurl to consider it to be too slow and abort.

By default this option is not set and corresponds to CURLOPT_LOW_SPEED_LIMIT.

Set the low speed time period.

Specifies the window of time for which if the transfer rate is below low_speed_limit the request will be aborted.

By default this option is not set and corresponds to CURLOPT_LOW_SPEED_TIME.

Rate limit data upload speed

If an upload exceeds this speed (counted in bytes per second) on cumulative average during the transfer, the transfer will pause to keep the average rate less than or equal to the parameter value.

By default this option is not set (unlimited speed) and corresponds to CURLOPT_MAX_SEND_SPEED_LARGE.

Rate limit data download speed

If a download exceeds this speed (counted in bytes per second) on cumulative average during the transfer, the transfer will pause to keep the average rate less than or equal to the parameter value.

By default this option is not set (unlimited speed) and corresponds to CURLOPT_MAX_RECV_SPEED_LARGE.

Set the maximum connection cache size.

The set amount will be the maximum number of simultaneously open persistent connections that libcurl may cache in the pool associated with this handle. The default is 5, and there isn't much point in changing this value unless you are perfectly aware of how this works and changes libcurl's behaviour. This concerns connections using any of the protocols that support persistent connections.

When reaching the maximum limit, curl closes the oldest one in the cache to prevent increasing the number of open connections.

By default this option is set to 5 and corresponds to CURLOPT_MAXCONNECTS

Force a new connection to be used.

Makes the next transfer use a new (fresh) connection by force instead of trying to re-use an existing one. This option should be used with caution and only if you understand what it does as it may seriously impact performance.

By default this option is false and corresponds to CURLOPT_FRESH_CONNECT.

Make connection get closed at once after use.

Makes libcurl explicitly close the connection when done with the transfer. Normally, libcurl keeps all connections alive when done with one transfer in case a succeeding one follows that can re-use them. This option should be used with caution and only if you understand what it does as it can seriously impact performance.

By default this option is false and corresponds to CURLOPT_FORBID_REUSE.

Timeout for the connect phase

This is the maximum time that you allow the connection phase to the server to take. This only limits the connection phase, it has no impact once it has connected.

By default this value is 300 seconds and corresponds to CURLOPT_CONNECTTIMEOUT_MS.

Specify which IP protocol version to use

Allows an application to select what kind of IP addresses to use when resolving host names. This is only interesting when using host names that resolve addresses using more than one version of IP.

By default this value is "any" and corresponds to CURLOPT_IPRESOLVE.

Configure whether to stop when connected to target server

When enabled it tells the library to perform all the required proxy authentication and connection setup, but no data transfer, and then return.

The option can be used to simply test a connection to a server.

By default this value is false and corresponds to CURLOPT_CONNECT_ONLY.

Sets the SSL client certificate.

The string should be the file name of your client certificate. The default format is "P12" on Secure Transport and "PEM" on other engines, and can be changed with ssl_cert_type.

With NSS or Secure Transport, this can also be the nickname of the certificate you wish to authenticate with as it is named in the security database. If you want to use a file from the current directory, please precede it with "./" prefix, in order to avoid confusion with a nickname.

When using a client certificate, you most likely also need to provide a private key with ssl_key.

By default this option is not set and corresponds to CURLOPT_SSLCERT.

Specify type of the client SSL certificate.

The string should be the format of your certificate. Supported formats are "PEM" and "DER", except with Secure Transport. OpenSSL (versions 0.9.3 and later) and Secure Transport (on iOS 5 or later, or OS X 10.7 or later) also support "P12" for PKCS#12-encoded files.

By default this option is "PEM" and corresponds to CURLOPT_SSLCERTTYPE.

Specify private keyfile for TLS and SSL client cert.

The string should be the file name of your private key. The default format is "PEM" and can be changed with ssl_key_type.

(iOS and Mac OS X only) This option is ignored if curl was built against Secure Transport. Secure Transport expects the private key to be already present in the keychain or PKCS#12 file containing the certificate.

By default this option is not set and corresponds to CURLOPT_SSLKEY.

Set type of the private key file.

The string should be the format of your private key. Supported formats are "PEM", "DER" and "ENG".

The format "ENG" enables you to load the private key from a crypto engine. In this case ssl_key is used as an identifier passed to the engine. You have to set the crypto engine with ssl_engine. "DER" format key file currently does not work because of a bug in OpenSSL.

By default this option is "PEM" and corresponds to CURLOPT_SSLKEYTYPE.

Set passphrase to private key.

This will be used as the password required to use the ssl_key. You never needed a pass phrase to load a certificate but you need one to load your private key.

By default this option is not set and corresponds to CURLOPT_KEYPASSWD.

Set the SSL engine identifier.

This will be used as the identifier for the crypto engine you want to use for your private key.

By default this option is not set and corresponds to CURLOPT_SSLENGINE.

Make this handle's SSL engine the default.

By default this option is not set and corresponds to CURLOPT_SSLENGINE_DEFAULT.

Set preferred HTTP version.

By default this option is not set and corresponds to CURLOPT_HTTP_VERSION.

Set preferred TLS/SSL version.

By default this option is not set and corresponds to CURLOPT_SSLVERSION.

Verify the certificate's name against host.

This should be disabled with great caution! It basically disables the security features of SSL if it is disabled.

By default this option is set to true and corresponds to CURLOPT_SSL_VERIFYHOST.

Verify the peer's SSL certificate.

This should be disabled with great caution! It basically disables the security features of SSL if it is disabled.

By default this option is set to true and corresponds to CURLOPT_SSL_VERIFYPEER.

Specify the path to Certificate Authority (CA) bundle

The file referenced should hold one or more certificates to verify the peer with.

This option is by default set to the system path where libcurl's cacert bundle is assumed to be stored, as established at build time.

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.

By default this option is the system defaults, and corresponds to CURLOPT_CAINFO.

Set the issuer SSL certificate filename

Specifies a file holding a CA certificate in PEM format. If the option is set, an additional check against the peer certificate is performed to verify the issuer is indeed the one associated with the certificate provided by the option. This additional check is useful in multi-level PKI where one needs to enforce that the peer certificate is from a specific branch of the tree.

This option makes sense only when used in combination with the ssl_verify_peer option. Otherwise, the result of the check is not considered as failure.

By default this option is not set and corresponds to CURLOPT_ISSUERCERT.

Specify directory holding CA certificates

Names a directory holding multiple CA certificates to verify the peer with. If libcurl is built against OpenSSL, the certificate directory must be prepared using the openssl c_rehash utility. This makes sense only when used in combination with the ssl_verify_peer option.

By default this option is not set and corresponds to CURLOPT_CAPATH.

Specify a Certificate Revocation List file

Names a file with the concatenation of CRL (in PEM format) to use in the certificate validation that occurs during the SSL exchange.

When curl is built to use NSS or GnuTLS, there is no way to influence the use of CRL passed to help in the verification process. When libcurl is built with OpenSSL support, X509_V_FLAG_CRL_CHECK and X509_V_FLAG_CRL_CHECK_ALL are both set, requiring CRL check against all the elements of the certificate chain if a CRL file is passed.

This option makes sense only when used in combination with the ssl_verify_peer option.

A specific error code (is_ssl_crl_badfile) is defined with the option. It is returned when the SSL exchange fails because the CRL file cannot be loaded. A failure in certificate verification due to a revocation information found in the CRL does not trigger this specific error.

By default this option is not set and corresponds to CURLOPT_CRLFILE.

Request SSL certificate information

Enable libcurl's certificate chain info gatherer. With this enabled, libcurl will extract lots of information and data about the certificates in the certificate chain used in the SSL connection.

By default this option is false and corresponds to CURLOPT_CERTINFO.

Specify a source for random data

The file will be used to read from to seed the random engine for SSL and more.

By default this option is not set and corresponds to CURLOPT_RANDOM_FILE.

Specify EGD socket path.

Indicates the path name to the Entropy Gathering Daemon socket. It will be used to seed the random engine for SSL.

By default this option is not set and corresponds to CURLOPT_EGDSOCKET.

Specify ciphers to use for TLS.

Holds the list of ciphers to use for the SSL connection. The list must be syntactically correct, it consists of one or more cipher strings separated by colons. Commas or spaces are also acceptable separators but colons are normally used, !, - and + can be used as operators.

For OpenSSL and GnuTLS valid examples of cipher lists include 'RC4-SHA', ´SHA1+DES´, 'TLSv1' and 'DEFAULT'. The default list is normally set when you compile OpenSSL.

You'll find more details about cipher lists on this URL:

https://www.openssl.org/docs/apps/ciphers.html

For NSS, valid examples of cipher lists include 'rsa_rc4_128_md5', ´rsa_aes_128_sha´, etc. With NSS you don't add/remove ciphers. If one uses this option then all known ciphers are disabled and only those passed in are enabled.

You'll find more details about the NSS cipher lists on this URL:

http://git.fedorahosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives

By default this option is not set and corresponds to CURLOPT_SSL_CIPHER_LIST.

Enable or disable use of the SSL session-ID cache

By default all transfers are done using the cache enabled. While nothing ever should get hurt by attempting to reuse SSL session-IDs, there seem to be or have been broken SSL implementations in the wild that may require you to disable this in order for you to succeed.

This corresponds to the CURLOPT_SSL_SESSIONID_CACHE option.

Set SSL behavior options

Inform libcurl about SSL specific behaviors.

This corresponds to the CURLOPT_SSL_OPTIONS option.

Get the last used URL

In cases when you've asked libcurl to follow redirects, it may not be the same value you set with url.

This methods corresponds to the CURLINFO_EFFECTIVE_URL option.

Returns Ok(None) if no effective url is listed or Err if an error happens or the underlying bytes aren't valid utf-8.

Get the last used URL, in bytes

In cases when you've asked libcurl to follow redirects, it may not be the same value you set with url.

This methods corresponds to the CURLINFO_EFFECTIVE_URL option.

Returns Ok(None) if no effective url is listed or Err if an error happens or the underlying bytes aren't valid utf-8.

Get the last response code

The stored value will be zero if no server response code has been received. Note that a proxy's CONNECT response should be read with http_connectcode and not this.

Corresponds to CURLINFO_RESPONSE_CODE and returns an error if this option is not supported.

Get the CONNECT response code

Returns the last received HTTP proxy response code to a CONNECT request. The returned value will be zero if no such response code was available.

Corresponds to CURLINFO_HTTP_CONNECTCODE and returns an error if this option is not supported.

Get the remote time of the retrieved document

Returns the remote time of the retrieved document (in number of seconds since 1 Jan 1970 in the GMT/UTC time zone). If you get None, it can be because of many reasons (it might be unknown, the server might hide it or the server doesn't support the command that tells document time etc) and the time of the document is unknown.

Note that you must tell the server to collect this information before the transfer is made, by using the filetime method to or you will unconditionally get a None back.

This corresponds to CURLINFO_FILETIME and may return an error if the option is not supported

Get total time of previous transfer

Returns the total time for the previous transfer, including name resolving, TCP connect etc.

Corresponds to CURLINFO_TOTAL_TIME and may return an error if the option isn't supported.

Get the name lookup time

Returns the total time from the start until the name resolving was completed.

Corresponds to CURLINFO_NAMELOOKUP_TIME and may return an error if the option isn't supported.

Get the time until connect

Returns the total time from the start until the connection to the remote host (or proxy) was completed.

Corresponds to CURLINFO_CONNECT_TIME and may return an error if the option isn't supported.

Get the time until the SSL/SSH handshake is completed

Returns the total time it took from the start until the SSL/SSH connect/handshake to the remote host was completed. This time is most often very near to the pretransfer_time time, except for cases such as HTTP pipelining where the pretransfer time can be delayed due to waits in line for the pipeline and more.

Corresponds to CURLINFO_APPCONNECT_TIME and may return an error if the option isn't supported.

Get the time until the file transfer start

Returns the total time it took from the start until the file transfer is just about to begin. This includes all pre-transfer commands and negotiations that are specific to the particular protocol(s) involved. It does not involve the sending of the protocol- specific request that triggers a transfer.

Corresponds to CURLINFO_PRETRANSFER_TIME and may return an error if the option isn't supported.

Get the time until the first byte is received

Returns the total time it took from the start until the first byte is received by libcurl. This includes pretransfer_time and also the time the server needs to calculate the result.

Corresponds to CURLINFO_STARTTRANSFER_TIME and may return an error if the option isn't supported.

Get the time for all redirection steps

Returns the total time it took for all redirection steps include name lookup, connect, pretransfer and transfer before final transaction was started. redirect_time contains the complete execution time for multiple redirections.

Corresponds to CURLINFO_REDIRECT_TIME and may return an error if the option isn't supported.

Get the number of redirects

Corresponds to CURLINFO_REDIRECT_COUNT and may return an error if the option isn't supported.

Get the URL a redirect would go to

Returns the URL a redirect would take you to if you would enable follow_location. This can come very handy if you think using the built-in libcurl redirect logic isn't good enough for you but you would still prefer to avoid implementing all the magic of figuring out the new URL.

Corresponds to CURLINFO_REDIRECT_URL and may return an error if the url isn't valid utf-8 or an error happens.

Get the URL a redirect would go to, in bytes

Returns the URL a redirect would take you to if you would enable follow_location. This can come very handy if you think using the built-in libcurl redirect logic isn't good enough for you but you would still prefer to avoid implementing all the magic of figuring out the new URL.

Corresponds to CURLINFO_REDIRECT_URL and may return an error.

Get size of retrieved headers

Corresponds to CURLINFO_HEADER_SIZE and may return an error if the option isn't supported.

Get size of sent request.

Corresponds to CURLINFO_REQUEST_SIZE and may return an error if the option isn't supported.

Get Content-Type

Returns the content-type of the downloaded object. This is the value read from the Content-Type: field. If you get None, it means that the server didn't send a valid Content-Type header or that the protocol used doesn't support this.

Corresponds to CURLINFO_CONTENT_TYPE and may return an error if the option isn't supported.

Get Content-Type, in bytes

Returns the content-type of the downloaded object. This is the value read from the Content-Type: field. If you get None, it means that the server didn't send a valid Content-Type header or that the protocol used doesn't support this.

Corresponds to CURLINFO_CONTENT_TYPE and may return an error if the option isn't supported.

Get errno number from last connect failure.

Note that the value is only set on failure, it is not reset upon a successful operation. The number is OS and system specific.

Corresponds to CURLINFO_OS_ERRNO and may return an error if the option isn't supported.

Get IP address of last connection.

Returns a string holding the IP address of the most recent connection done with this curl handle. This string may be IPv6 when that is enabled.

Corresponds to CURLINFO_PRIMARY_IP and may return an error if the option isn't supported.

Get the latest destination port number

Corresponds to CURLINFO_PRIMARY_PORT and may return an error if the option isn't supported.

Get local IP address of last connection

Returns a string holding the IP address of the local end of most recent connection done with this curl handle. This string may be IPv6 when that is enabled.

Corresponds to CURLINFO_LOCAL_IP and may return an error if the option isn't supported.

Get the latest local port number

Corresponds to CURLINFO_LOCAL_PORT and may return an error if the option isn't supported.

Get all known cookies

Returns a linked-list of all cookies cURL knows (expired ones, too).

Corresponds to the CURLINFO_COOKIELIST option and may return an error if the option isn't supported.

After options have been set, this will perform the transfer described by the options.

This performs the request in a synchronous fashion. This can be used multiple times for one easy handle and libcurl will attempt to re-use the same connection for all transfers.

This method will preserve all options configured in this handle for the next request, and if that is not desired then the options can be manually reset or the reset method can be called.

Note that this method takes &self, which is quite important! This allows applications to close over the handle in various callbacks to call methods like unpause_write and unpause_read while a transfer is in progress.

Creates a new scoped transfer which can be used to set callbacks and data which only live for the scope of the returned object.

An Easy handle is often reused between different requests to cache connections to servers, but often the lifetime of the data as part of each transfer is unique. This function serves as an ability to share an Easy across many transfers while ergonomically using possibly stack-local data as part of each transfer.

Configuration can be set on the Easy and then a Transfer can be created to set scoped configuration (like callbacks). Finally, the perform method on the Transfer function can be used.

When the Transfer option is dropped then all configuration set on the transfer itself will be reset.

Unpause reading on a connection.

Using this function, you can explicitly unpause a connection that was previously paused.

A connection can be paused by letting the read or the write callbacks return ReadError::Pause or WriteError::Pause.

To unpause, you may for example call this from the progress callback which gets called at least once per second, even if the connection is paused.

The chance is high that you will get your write callback called before this function returns.

Unpause writing on a connection.

Using this function, you can explicitly unpause a connection that was previously paused.

A connection can be paused by letting the read or the write callbacks return ReadError::Pause or WriteError::Pause. A write callback that returns pause signals to the library that it couldn't take care of any data at all, and that data will then be delivered again to the callback when the writing is later unpaused.

To unpause, you may for example call this from the progress callback which gets called at least once per second, even if the connection is paused.

URL encodes a string s

URL decodes a string s, returning None if it fails

Re-initializes this handle to the default values.

This puts the handle to the same state as it was in when it was just created. This does, however, keep live connections, the session id cache, the dns cache, and cookies.

Receives data from a connected socket.

Only useful after a successful perform with the connect_only option set as well.

Sends data over the connected socket.

Only useful after a successful perform with the connect_only option set as well.

Get a pointer to the raw underlying CURL handle.

Trait Implementations

impl Send for Easy
[src]

impl Drop for Easy
[src]

A method called when the value goes out of scope. Read more