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NAME |
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AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client |
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|
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SYNOPSIS |
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use AnyEvent::HTTP; |
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|
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http_get "http://www.nethype.de/", sub { print $_[1] }; |
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|
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# ... do something else here |
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|
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DESCRIPTION |
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This module is an AnyEvent user, you need to make sure that you use and |
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run a supported event loop. |
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|
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This module implements a simple, stateless and non-blocking HTTP client. |
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It supports GET, POST and other request methods, cookies and more, all |
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on a very low level. It can follow redirects supports proxies and |
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automatically limits the number of connections to the values specified |
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in the RFC. |
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|
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It should generally be a "good client" that is enough for most HTTP |
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tasks. Simple tasks should be simple, but complex tasks should still be |
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possible as the user retains control over request and response headers. |
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|
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The caller is responsible for authentication management, cookies (if the |
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simplistic implementation in this module doesn't suffice), referer and |
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other high-level protocol details for which this module offers only |
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limited support. |
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|
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METHODS |
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http_get $url, key => value..., $cb->($data, $headers) |
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Executes an HTTP-GET request. See the http_request function for |
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details on additional parameters. |
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|
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http_head $url, key => value..., $cb->($data, $headers) |
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Executes an HTTP-HEAD request. See the http_request function for |
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details on additional parameters. |
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|
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http_post $url, $body, key => value..., $cb->($data, $headers) |
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Executes an HTTP-POST request with a request body of $body. See the |
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http_request function for details on additional parameters. |
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|
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http_request $method => $url, key => value..., $cb->($data, $headers) |
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Executes a HTTP request of type $method (e.g. "GET", "POST"). The |
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URL must be an absolute http or https URL. |
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|
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The callback will be called with the response data as first argument |
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(or "undef" if it wasn't available due to errors), and a hash-ref |
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with response headers as second argument. |
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|
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All the headers in that hash are lowercased. In addition to the |
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response headers, the "pseudo-headers" "HTTPVersion", "Status" and |
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"Reason" contain the three parts of the HTTP Status-Line of the same |
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name. The pseudo-header "URL" contains the original URL (which can |
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differ from the requested URL when following redirects). |
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|
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If the server sends a header multiple lines, then their contents |
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will be joined together with "\x00". |
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|
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If an internal error occurs, such as not being able to resolve a |
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hostname, then $data will be "undef", "$headers->{Status}" will be |
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599 and the "Reason" pseudo-header will contain an error message. |
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|
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A typical callback might look like this: |
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|
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sub { |
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my ($body, $hdr) = @_; |
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|
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if ($hdr->{Status} =~ /^2/) { |
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... everything should be ok |
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} else { |
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print "error, $hdr->{Status} $hdr->{Reason}\n"; |
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} |
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} |
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|
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Additional parameters are key-value pairs, and are fully optional. |
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They include: |
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|
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recurse => $count (default: $MAX_RECURSE) |
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Whether to recurse requests or not, e.g. on redirects, |
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authentication retries and so on, and how often to do so. |
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|
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headers => hashref |
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The request headers to use. Currently, "http_request" may |
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provide its own "Host:", "Content-Length:", "Connection:" and |
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"Cookie:" headers and will provide defaults for "User-Agent:" |
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and "Referer:". |
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|
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timeout => $seconds |
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The time-out to use for various stages - each connect attempt |
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will reset the timeout, as will read or write activity. Default |
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timeout is 5 minutes. |
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|
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proxy => [$host, $port[, $scheme]] or undef |
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Use the given http proxy for all requests. If not specified, |
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then the default proxy (as specified by $ENV{http_proxy}) is |
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used. |
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|
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$scheme must be either missing or "http" for HTTP, or "https" |
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for HTTPS. |
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|
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body => $string |
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The request body, usually empty. Will be-sent as-is (future |
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versions of this module might offer more options). |
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|
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cookie_jar => $hash_ref |
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Passing this parameter enables (simplified) cookie-processing, |
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loosely based on the original netscape specification. |
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|
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The $hash_ref must be an (initially empty) hash reference which |
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will get updated automatically. It is possible to save the |
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cookie_jar to persistent storage with something like JSON or |
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Storable, but this is not recommended, as expire times are |
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currently being ignored. |
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|
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Note that this cookie implementation is not of very high |
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quality, nor meant to be complete. If you want complete cookie |
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management you have to do that on your own. "cookie_jar" is |
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meant as a quick fix to get some cookie-using sites working. |
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Cookies are a privacy disaster, do not use them unless required |
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to. |
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|
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Example: make a simple HTTP GET request for http://www.nethype.de/ |
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|
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http_request GET => "http://www.nethype.de/", sub { |
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my ($body, $hdr) = @_; |
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print "$body\n"; |
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}; |
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|
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Example: make a HTTP HEAD request on https://www.google.com/, use a |
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timeout of 30 seconds. |
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|
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http_request |
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GET => "https://www.google.com", |
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timeout => 30, |
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sub { |
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my ($body, $hdr) = @_; |
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use Data::Dumper; |
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print Dumper $hdr; |
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} |
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; |
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|
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GLOBAL FUNCTIONS AND VARIABLES |
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AnyEvent::HTTP::set_proxy "proxy-url" |
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Sets the default proxy server to use. The proxy-url must begin with |
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a string of the form "http://host:port" (optionally "https:..."). |
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|
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$AnyEvent::HTTP::MAX_RECURSE |
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The default value for the "recurse" request parameter (default: 10). |
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|
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$AnyEvent::HTTP::USERAGENT |
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The default value for the "User-Agent" header (the default is |
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"Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION; |
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+http://software.schmorp.de/pkg/AnyEvent)"). |
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|
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$AnyEvent::HTTP::MAX_PERSISTENT |
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The maximum number of persistent connections to keep open (default: |
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8). |
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|
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Not implemented currently. |
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|
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$AnyEvent::HTTP::PERSISTENT_TIMEOUT |
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The maximum time to cache a persistent connection, in seconds |
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(default: 2). |
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|
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Not implemented currently. |
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|
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$AnyEvent::HTTP::ACTIVE |
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The number of active connections. This is not the number of |
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currently running requests, but the number of currently open and |
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non-idle TCP connections. This number of can be useful for |
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load-leveling. |
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|
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SEE ALSO |
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AnyEvent. |
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|
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AUTHOR |
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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