[ViewVC] Diff of: cvs/AnyEvent-HTTP/README

Comparing AnyEvent-HTTP/README (file contents):
Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs.
Revision 1.24 by root, Wed Nov 14 22:22:24 2012 UTC

…		…
12	This module is an AnyEvent user, you need to make sure that you use and	12	This module is an AnyEvent user, you need to make sure that you use and
13	run a supported event loop.	13	run a supported event loop.
14		14
15	This module implements a simple, stateless and non-blocking HTTP client.	15	This module implements a simple, stateless and non-blocking HTTP client.
16	It supports GET, POST and other request methods, cookies and more, all	16	It supports GET, POST and other request methods, cookies and more, all
17	on a very low level. It can follow redirects supports proxies and	17	on a very low level. It can follow redirects, supports proxies, and
18	automatically limits the number of connections to the values specified	18	automatically limits the number of connections to the values specified
19	in the RFC.	19	in the RFC.
20		20
21	It should generally be a "good client" that is enough for most HTTP	21	It should generally be a "good client" that is enough for most HTTP
22	tasks. Simple tasks should be simple, but complex tasks should still be	22	tasks. Simple tasks should be simple, but complex tasks should still be
…		…
46	URL must be an absolute http or https URL.	46	URL must be an absolute http or https URL.
47		47
48	When called in void context, nothing is returned. In other contexts,	48	When called in void context, nothing is returned. In other contexts,
49	"http_request" returns a "cancellation guard" - you have to keep the	49	"http_request" returns a "cancellation guard" - you have to keep the
50	object at least alive until the callback get called. If the object	50	object at least alive until the callback get called. If the object
51	gets destroyed before the callbakc is called, the request will be	51	gets destroyed before the callback is called, the request will be
52	cancelled.	52	cancelled.
53		53
54	The callback will be called with the response body data as first	54	The callback will be called with the response body data as first
55	argument (or "undef" if an error occured), and a hash-ref with	55	argument (or "undef" if an error occured), and a hash-ref with
56	response headers as second argument.	56	response headers (and trailers) as second argument.
57		57
58	All the headers in that hash are lowercased. In addition to the	58	All the headers in that hash are lowercased. In addition to the
59	response headers, the "pseudo-headers" "HTTPVersion", "Status" and	59	response headers, the "pseudo-headers" (uppercase to avoid clashing
		60	with possible response headers) "HTTPVersion", "Status" and "Reason"
60	"Reason" contain the three parts of the HTTP Status-Line of the same	61	contain the three parts of the HTTP Status-Line of the same name. If
		62	an error occurs during the body phase of a request, then the
		63	original "Status" and "Reason" values from the header are available
		64	as "OrigStatus" and "OrigReason".
		65
61	name. The pseudo-header "URL" contains the original URL (which can	66	The pseudo-header "URL" contains the actual URL (which can differ
62	differ from the requested URL when following redirects).	67	from the requested URL when following redirects - for example, you
		68	might get an error that your URL scheme is not supported even though
		69	your URL is a valid http URL because it redirected to an ftp URL, in
		70	which case you can look at the URL pseudo header).
		71
		72	The pseudo-header "Redirect" only exists when the request was a
		73	result of an internal redirect. In that case it is an array
		74	reference with the "($data, $headers)" from the redirect response.
		75	Note that this response could in turn be the result of a redirect
		76	itself, and "$headers->{Redirect}[1]{Redirect}" will then contain
		77	the original response, and so on.
63		78
64	If the server sends a header multiple times, then their contents	79	If the server sends a header multiple times, then their contents
65	will be joined together with a comma (","), as per the HTTP spec.	80	will be joined together with a comma (","), as per the HTTP spec.
66		81
67	If an internal error occurs, such as not being able to resolve a	82	If an internal error occurs, such as not being able to resolve a
68	hostname, then $data will be "undef", "$headers->{Status}" will be	83	hostname, then $data will be "undef", "$headers->{Status}" will be
69	"59x" (usually 599) and the "Reason" pseudo-header will contain an	84	590-599 and the "Reason" pseudo-header will contain an error
70	error message.	85	message. Currently the following status codes are used:
		86
		87	595 - errors during connection etsbalishment, proxy handshake.
		88	596 - errors during TLS negotiation, request sending and header
		89	processing.
		90	597 - errors during body receiving or processing.
		91	598 - user aborted request via "on_header" or "on_body".
		92	599 - other, usually nonretryable, errors (garbled URL etc.).
71		93
72	A typical callback might look like this:	94	A typical callback might look like this:
73		95
74	sub {	96	sub {
75	my ($body, $hdr) = @_;	97	my ($body, $hdr) = @_;
…		…
84	Additional parameters are key-value pairs, and are fully optional.	106	Additional parameters are key-value pairs, and are fully optional.
85	They include:	107	They include:
86		108
87	recurse => $count (default: $MAX_RECURSE)	109	recurse => $count (default: $MAX_RECURSE)
88	Whether to recurse requests or not, e.g. on redirects,	110	Whether to recurse requests or not, e.g. on redirects,
89	authentication retries and so on, and how often to do so.	111	authentication and other retries and so on, and how often to do
		112	so.
90		113
91	headers => hashref	114	headers => hashref
92	The request headers to use. Currently, "http_request" may	115	The request headers to use. Currently, "http_request" may
93	provide its own "Host:", "Content-Length:", "Connection:" and	116	provide its own "Host:", "Content-Length:", "Connection:" and
94	"Cookie:" headers and will provide defaults for "User-Agent:"	117	"Cookie:" headers and will provide defaults at least for "TE:",
95	and "Referer:" (this can be suppressed by using "undef" for	118	"Referer:" and "User-Agent:" (this can be suppressed by using
96	these headers in which case they won't be sent at all).	119	"undef" for these headers in which case they won't be sent at
		120	all).
		121
		122	You really should provide your own "User-Agent:" header value
		123	that is appropriate for your program - I wouldn't be surprised
		124	if the default AnyEvent string gets blocked by webservers sooner
		125	or later.
		126
		127	Also, make sure that your headers names and values do not
		128	contain any embedded newlines.
97		129
98	timeout => $seconds	130	timeout => $seconds
99	The time-out to use for various stages - each connect attempt	131	The time-out to use for various stages - each connect attempt
100	will reset the timeout, as will read or write activity, i.e.	132	will reset the timeout, as will read or write activity, i.e.
101	this is not an overall timeout.	133	this is not an overall timeout.
102		134
103	Default timeout is 5 minutes.	135	Default timeout is 5 minutes.
104		136
105	proxy => [$host, $port[, $scheme]] or undef	137	proxy => [$host, $port[, $scheme]] or undef
106	Use the given http proxy for all requests. If not specified,	138	Use the given http proxy for all requests, or no proxy if
107	then the default proxy (as specified by $ENV{http_proxy}) is
108	used.	139	"undef" is used.
109		140
110	$scheme must be either missing, "http" for HTTP or "https" for	141	$scheme must be either missing or must be "http" for HTTP.
111	HTTPS.	142
		143	If not specified, then the default proxy is used (see
		144	"AnyEvent::HTTP::set_proxy").
112		145
113	body => $string	146	body => $string
114	The request body, usually empty. Will be-sent as-is (future	147	The request body, usually empty. Will be sent as-is (future
115	versions of this module might offer more options).	148	versions of this module might offer more options).
116		149
117	cookie_jar => $hash_ref	150	cookie_jar => $hash_ref
118	Passing this parameter enables (simplified) cookie-processing,	151	Passing this parameter enables (simplified) cookie-processing,
119	loosely based on the original netscape specification.	152	loosely based on the original netscape specification.
120		153
121	The $hash_ref must be an (initially empty) hash reference which	154	The $hash_ref must be an (initially empty) hash reference which
122	will get updated automatically. It is possible to save the	155	will get updated automatically. It is possible to save the
123	cookie_jar to persistent storage with something like JSON or	156	cookie jar to persistent storage with something like JSON or
124	Storable, but this is not recommended, as expiry times are	157	Storable - see the "AnyEvent::HTTP::cookie_jar_expire" function
125	currently being ignored.	158	if you wish to remove expired or session-only cookies, and also
		159	for documentation on the format of the cookie jar.
126		160
127	Note that this cookie implementation is not of very high	161	Note that this cookie implementation is not meant to be
128	quality, nor meant to be complete. If you want complete cookie	162	complete. If you want complete cookie management you have to do
129	management you have to do that on your own. "cookie_jar" is	163	that on your own. "cookie_jar" is meant as a quick fix to get
130	meant as a quick fix to get some cookie-using sites working.	164	most cookie-using sites working. Cookies are a privacy disaster,
131	Cookies are a privacy disaster, do not use them unless required	165	do not use them unless required to.
132	to.	166
		167	When cookie processing is enabled, the "Cookie:" and
		168	"Set-Cookie:" headers will be set and handled by this module,
		169	otherwise they will be left untouched.
133		170
134	tls_ctx => $scheme \| $tls_ctx	171	tls_ctx => $scheme \| $tls_ctx
135	Specifies the AnyEvent::TLS context to be used for https	172	Specifies the AnyEvent::TLS context to be used for https
136	connections. This parameter follows the same rules as the	173	connections. This parameter follows the same rules as the
137	"tls_ctx" parameter to AnyEvent::Handle, but additionally, the	174	"tls_ctx" parameter to AnyEvent::Handle, but additionally, the
…		…
139	predefined low-security (no verification, highest compatibility)	176	predefined low-security (no verification, highest compatibility)
140	and high-security (CA and common-name verification) TLS context.	177	and high-security (CA and common-name verification) TLS context.
141		178
142	The default for this option is "low", which could be interpreted	179	The default for this option is "low", which could be interpreted
143	as "give me the page, no matter what".	180	as "give me the page, no matter what".
		181
		182	See also the "sessionid" parameter.
		183
		184	session => $string
		185	The module might reuse connections to the same host internally.
		186	Sometimes (e.g. when using TLS), you do not want to reuse
		187	connections from other sessions. This can be achieved by setting
		188	this parameter to some unique ID (such as the address of an
		189	object storing your state data, or the TLS context) - only
		190	connections using the same unique ID will be reused.
144		191
145	on_prepare => $callback->($fh)	192	on_prepare => $callback->($fh)
146	In rare cases you need to "tune" the socket before it is used to	193	In rare cases you need to "tune" the socket before it is used to
147	connect (for exmaple, to bind it on a given IP address). This	194	connect (for exmaple, to bind it on a given IP address). This
148	parameter overrides the prepare callback passed to	195	parameter overrides the prepare callback passed to
149	"AnyEvent::Socket::tcp_connect" and behaves exactly the same way	196	"AnyEvent::Socket::tcp_connect" and behaves exactly the same way
150	(e.g. it has to provide a timeout). See the description for the	197	(e.g. it has to provide a timeout). See the description for the
151	$prepare_cb argument of "AnyEvent::Socket::tcp_connect" for	198	$prepare_cb argument of "AnyEvent::Socket::tcp_connect" for
152	details.	199	details.
153		200
		201	tcp_connect => $callback->($host, $service, $connect_cb,
		202	$prepare_cb)
		203	In even rarer cases you want total control over how
		204	AnyEvent::HTTP establishes connections. Normally it uses
		205	AnyEvent::Socket::tcp_connect to do this, but you can provide
		206	your own "tcp_connect" function - obviously, it has to follow
		207	the same calling conventions, except that it may always return a
		208	connection guard object.
		209
		210	There are probably lots of weird uses for this function,
		211	starting from tracing the hosts "http_request" actually tries to
		212	connect, to (inexact but fast) host => IP address caching or
		213	even socks protocol support.
		214
154	on_header => $callback->($headers)	215	on_header => $callback->($headers)
155	When specified, this callback will be called with the header	216	When specified, this callback will be called with the header
156	hash as soon as headers have been successfully received from the	217	hash as soon as headers have been successfully received from the
157	remote server (not on locally-generated errors).	218	remote server (not on locally-generated errors).
158		219
…		…
163		224
164	This callback is useful, among other things, to quickly reject	225	This callback is useful, among other things, to quickly reject
165	unwanted content, which, if it is supposed to be rare, can be	226	unwanted content, which, if it is supposed to be rare, can be
166	faster than first doing a "HEAD" request.	227	faster than first doing a "HEAD" request.
167		228
		229	The downside is that cancelling the request makes it impossible
		230	to re-use the connection. Also, the "on_header" callback will
		231	not receive any trailer (headers sent after the response body).
		232
168	Example: cancel the request unless the content-type is	233	Example: cancel the request unless the content-type is
169	"text/html".	234	"text/html".
170		235
171	on_header => sub {	236	on_header => sub {
172	$_[0]{"content-type"} =~ /^text\/html\s*(?:;\|$)/	237	$_[0]{"content-type"} =~ /^text\/html\s*(?:;\|$)/
…		…
179		244
180	It has to return either true (in which case AnyEvent::HTTP will	245	It has to return either true (in which case AnyEvent::HTTP will
181	continue), or false, in which case AnyEvent::HTTP will cancel	246	continue), or false, in which case AnyEvent::HTTP will cancel
182	the download (and call the completion callback with an error	247	the download (and call the completion callback with an error
183	code of 598).	248	code of 598).
		249
		250	The downside to cancelling the request is that it makes it
		251	impossible to re-use the connection.
184		252
185	This callback is useful when the data is too large to be held in	253	This callback is useful when the data is too large to be held in
186	memory (so the callback writes it to a file) or when only some	254	memory (so the callback writes it to a file) or when only some
187	information should be extracted, or when the body should be	255	information should be extracted, or when the body should be
188	processed incrementally.	256	processed incrementally.
…		…
202	AnyEvent::Handle object associated with the connection. In error	270	AnyEvent::Handle object associated with the connection. In error
203	cases, "undef" will be passed. When there is no body (e.g.	271	cases, "undef" will be passed. When there is no body (e.g.
204	status 304), the empty string will be passed.	272	status 304), the empty string will be passed.
205		273
206	The handle object might or might not be in TLS mode, might be	274	The handle object might or might not be in TLS mode, might be
207	connected to a proxy, be a persistent connection etc., and	275	connected to a proxy, be a persistent connection, use chunked
208	configured in unspecified ways. The user is responsible for this	276	transfer encoding etc., and configured in unspecified ways. The
209	handle (it will not be used by this module anymore).	277	user is responsible for this handle (it will not be used by this
		278	module anymore).
210		279
211	This is useful with some push-type services, where, after the	280	This is useful with some push-type services, where, after the
212	initial headers, an interactive protocol is used (typical	281	initial headers, an interactive protocol is used (typical
213	example would be the push-style twitter API which starts a	282	example would be the push-style twitter API which starts a
214	JSON/XML stream).	283	JSON/XML stream).
215		284
216	If you think you need this, first have a look at "on_body", to	285	If you think you need this, first have a look at "on_body", to
217	see if that doesn't solve your problem in a better way.	286	see if that doesn't solve your problem in a better way.
218		287
		288	persistent => $boolean
		289	Try to create/reuse a persistent connection. When this flag is
		290	set (default: true for idempotent requests, false for all
		291	others), then "http_request" tries to re-use an existing
		292	(previously-created) persistent connection to the host and,
		293	failing that, tries to create a new one.
		294
		295	Requests failing in certain ways will be automatically retried
		296	once, which is dangerous for non-idempotent requests, which is
		297	why it defaults to off for them. The reason for this is because
		298	the bozos who designed HTTP/1.1 made it impossible to
		299	distinguish between a fatal error and a normal connection
		300	timeout, so you never know whether there was a problem with your
		301	request or not.
		302
		303	When reusing an existent connection, many parameters (such as
		304	TLS context) will be ignored. See the "session" parameter for a
		305	workaround.
		306
		307	keepalive => $boolean
		308	Only used when "persistent" is also true. This parameter decides
		309	whether "http_request" tries to handshake a HTTP/1.0-style
		310	keep-alive connection (as opposed to only a HTTP/1.1 persistent
		311	connection).
		312
		313	The default is true, except when using a proxy, in which case it
		314	defaults to false, as HTTP/1.0 proxies cannot support this in a
		315	meaningful way.
		316
		317	handle_params => { key => value ... }
		318	The key-value pairs in this hash will be passed to any
		319	AnyEvent::Handle constructor that is called - not all requests
		320	will create a handle, and sometimes more than one is created, so
		321	this parameter is only good for setting hints.
		322
		323	Example: set the maximum read size to 4096, to potentially
		324	conserve memory at the cost of speed.
		325
		326	handle_params => {
		327	max_read_size => 4096,
		328	},
		329
219	Example: make a simple HTTP GET request for http://www.nethype.de/	330	Example: do a simple HTTP GET request for http://www.nethype.de/ and
		331	print the response body.
220		332
221	http_request GET => "http://www.nethype.de/", sub {	333	http_request GET => "http://www.nethype.de/", sub {
222	my ($body, $hdr) = @_;	334	my ($body, $hdr) = @_;
223	print "$body\n";	335	print "$body\n";
224	};	336	};
225		337
226	Example: make a HTTP HEAD request on https://www.google.com/, use a	338	Example: do a HTTP HEAD request on https://www.google.com/, use a
227	timeout of 30 seconds.	339	timeout of 30 seconds.
228		340
229	http_request	341	http_request
230	GET => "https://www.google.com",	342	HEAD => "https://www.google.com",
		343	headers => { "user-agent" => "MySearchClient 1.0" },
231	timeout => 30,	344	timeout => 30,
232	sub {	345	sub {
233	my ($body, $hdr) = @_;	346	my ($body, $hdr) = @_;
234	use Data::Dumper;	347	use Data::Dumper;
235	print Dumper $hdr;	348	print Dumper $hdr;
236	}	349	}
237	;	350	;
238		351
239	Example: make another simple HTTP GET request, but immediately try	352	Example: do another simple HTTP GET request, but immediately try to
240	to cancel it.	353	cancel it.
241		354
242	my $request = http_request GET => "http://www.nethype.de/", sub {	355	my $request = http_request GET => "http://www.nethype.de/", sub {
243	my ($body, $hdr) = @_;	356	my ($body, $hdr) = @_;
244	print "$body\n";	357	print "$body\n";
245	};	358	};
246		359
247	undef $request;	360	undef $request;
248		361
		362	DNS CACHING
		363	AnyEvent::HTTP uses the AnyEvent::Socket::tcp_connect function for the
		364	actual connection, which in turn uses AnyEvent::DNS to resolve
		365	hostnames. The latter is a simple stub resolver and does no caching on
		366	its own. If you want DNS caching, you currently have to provide your own
		367	default resolver (by storing a suitable resolver object in
		368	$AnyEvent::DNS::RESOLVER) or your own "tcp_connect" callback.
		369
249	GLOBAL FUNCTIONS AND VARIABLES	370	GLOBAL FUNCTIONS AND VARIABLES
250	AnyEvent::HTTP::set_proxy "proxy-url"	371	AnyEvent::HTTP::set_proxy "proxy-url"
251	Sets the default proxy server to use. The proxy-url must begin with	372	Sets the default proxy server to use. The proxy-url must begin with
252	a string of the form "http://host:port" (optionally "https:..."),	373	a string of the form "http://host:port", croaks otherwise.
253	croaks otherwise.
254		374
255	To clear an already-set proxy, use "undef".	375	To clear an already-set proxy, use "undef".
		376
		377	When AnyEvent::HTTP is laoded for the first time it will query the
		378	default proxy from the operating system, currently by looking at
		379	"$ENV{http_proxy"}.
		380
		381	AnyEvent::HTTP::cookie_jar_expire $jar[, $session_end]
		382	Remove all cookies from the cookie jar that have been expired. If
		383	$session_end is given and true, then additionally remove all session
		384	cookies.
		385
		386	You should call this function (with a true $session_end) before you
		387	save cookies to disk, and you should call this function after
		388	loading them again. If you have a long-running program you can
		389	additonally call this function from time to time.
		390
		391	A cookie jar is initially an empty hash-reference that is managed by
		392	this module. It's format is subject to change, but currently it is
		393	like this:
		394
		395	The key "version" has to contain 1, otherwise the hash gets emptied.
		396	All other keys are hostnames or IP addresses pointing to
		397	hash-references. The key for these inner hash references is the
		398	server path for which this cookie is meant, and the values are again
		399	hash-references. The keys of those hash-references is the cookie
		400	name, and the value, you guessed it, is another hash-reference, this
		401	time with the key-value pairs from the cookie, except for "expires"
		402	and "max-age", which have been replaced by a "_expires" key that
		403	contains the cookie expiry timestamp.
		404
		405	Here is an example of a cookie jar with a single cookie, so you have
		406	a chance of understanding the above paragraph:
		407
		408	{
		409	version => 1,
		410	"10.0.0.1" => {
		411	"/" => {
		412	"mythweb_id" => {
		413	_expires => 1293917923,
		414	value => "ooRung9dThee3ooyXooM1Ohm",
		415	},
		416	},
		417	},
		418	}
		419
		420	$date = AnyEvent::HTTP::format_date $timestamp
		421	Takes a POSIX timestamp (seconds since the epoch) and formats it as
		422	a HTTP Date (RFC 2616).
		423
		424	$timestamp = AnyEvent::HTTP::parse_date $date
		425	Takes a HTTP Date (RFC 2616) or a Cookie date (netscape cookie spec)
		426	or a bunch of minor variations of those, and returns the
		427	corresponding POSIX timestamp, or "undef" if the date cannot be
		428	parsed.
256		429
257	$AnyEvent::HTTP::MAX_RECURSE	430	$AnyEvent::HTTP::MAX_RECURSE
258	The default value for the "recurse" request parameter (default: 10).	431	The default value for the "recurse" request parameter (default: 10).
		432
		433	$AnyEvent::HTTP::TIMEOUT
		434	The default timeout for connection operations (default: 300).
259		435
260	$AnyEvent::HTTP::USERAGENT	436	$AnyEvent::HTTP::USERAGENT
261	The default value for the "User-Agent" header (the default is	437	The default value for the "User-Agent" header (the default is
262	"Mozilla/5.0 (compatible; U; AnyEvent-HTTP/$VERSION;	438	"Mozilla/5.0 (compatible; U; AnyEvent-HTTP/$VERSION;
263	+http://software.schmorp.de/pkg/AnyEvent)").	439	+http://software.schmorp.de/pkg/AnyEvent)").
264		440
265	$AnyEvent::HTTP::MAX_PER_HOST	441	$AnyEvent::HTTP::MAX_PER_HOST
266	The maximum number of concurrent connections to the same host	442	The maximum number of concurrent connections to the same host
267	(identified by the hostname). If the limit is exceeded, then the	443	(identified by the hostname). If the limit is exceeded, then the
268	additional requests are queued until previous connections are	444	additional requests are queued until previous connections are
269	closed.	445	closed. Both persistent and non-persistent connections are counted
		446	in this limit.
270		447
271	The default value for this is 4, and it is highly advisable to not	448	The default value for this is 4, and it is highly advisable to not
272	increase it.	449	increase it much.
		450
		451	For comparison: the RFC's recommend 4 non-persistent or 2 persistent
		452	connections, older browsers used 2, newers (such as firefox 3)
		453	typically use 6, and Opera uses 8 because like, they have the
		454	fastest browser and give a shit for everybody else on the planet.
		455
		456	$AnyEvent::HTTP::PERSISTENT_TIMEOUT
		457	The time after which idle persistent conenctions get closed by
		458	AnyEvent::HTTP (default: 3).
273		459
274	$AnyEvent::HTTP::ACTIVE	460	$AnyEvent::HTTP::ACTIVE
275	The number of active connections. This is not the number of	461	The number of active connections. This is not the number of
276	currently running requests, but the number of currently open and	462	currently running requests, but the number of currently open and
277	non-idle TCP connections. This number of can be useful for	463	non-idle TCP connections. This number can be useful for
278	load-leveling.	464	load-leveling.
		465
		466	SHOWCASE
		467	This section contaisn some more elaborate "real-world" examples or code
		468	snippets.
		469
		470	HTTP/1.1 FILE DOWNLOAD
		471	Downloading files with HTTP can be quite tricky, especially when
		472	something goes wrong and you want to resume.
		473
		474	Here is a function that initiates and resumes a download. It uses the
		475	last modified time to check for file content changes, and works with
		476	many HTTP/1.0 servers as well, and usually falls back to a complete
		477	re-download on older servers.
		478
		479	It calls the completion callback with either "undef", which means a
		480	nonretryable error occured, 0 when the download was partial and should
		481	be retried, and 1 if it was successful.
		482
		483	use AnyEvent::HTTP;
		484
		485	sub download($$$) {
		486	my ($url, $file, $cb) = @_;
		487
		488	open my $fh, "+<", $file
		489	or die "$file: $!";
		490
		491	my %hdr;
		492	my $ofs = 0;
		493
		494	warn stat $fh;
		495	warn -s _;
		496	if (stat $fh and -s _) {
		497	$ofs = -s _;
		498	warn "-s is ", $ofs;
		499	$hdr{"if-unmodified-since"} = AnyEvent::HTTP::format_date +(stat _)[9];
		500	$hdr{"range"} = "bytes=$ofs-";
		501	}
		502
		503	http_get $url,
		504	headers => \%hdr,
		505	on_header => sub {
		506	my ($hdr) = @_;
		507
		508	if ($hdr->{Status} == 200 && $ofs) {
		509	# resume failed
		510	truncate $fh, $ofs = 0;
		511	}
		512
		513	sysseek $fh, $ofs, 0;
		514
		515	1
		516	},
		517	on_body => sub {
		518	my ($data, $hdr) = @_;
		519
		520	if ($hdr->{Status} =~ /^2/) {
		521	length $data == syswrite $fh, $data
		522	or return; # abort on write errors
		523	}
		524
		525	1
		526	},
		527	sub {
		528	my (undef, $hdr) = @_;
		529
		530	my $status = $hdr->{Status};
		531
		532	if (my $time = AnyEvent::HTTP::parse_date $hdr->{"last-modified"}) {
		533	utime $fh, $time, $time;
		534	}
		535
		536	if ($status == 200 \|\| $status == 206 \|\| $status == 416) {
		537	# download ok \|\| resume ok \|\| file already fully downloaded
		538	$cb->(1, $hdr);
		539
		540	} elsif ($status == 412) {
		541	# file has changed while resuming, delete and retry
		542	unlink $file;
		543	$cb->(0, $hdr);
		544
		545	} elsif ($status == 500 or $status == 503 or $status =~ /^59/) {
		546	# retry later
		547	$cb->(0, $hdr);
		548
		549	} else {
		550	$cb->(undef, $hdr);
		551	}
		552	}
		553	;
		554	}
		555
		556	download "http://server/somelargefile", "/tmp/somelargefile", sub {
		557	if ($_[0]) {
		558	print "OK!\n";
		559	} elsif (defined $_[0]) {
		560	print "please retry later\n";
		561	} else {
		562	print "ERROR\n";
		563	}
		564	};
		565
		566	SOCKS PROXIES
		567	Socks proxies are not directly supported by AnyEvent::HTTP. You can
		568	compile your perl to support socks, or use an external program such as
		569	socksify (dante) or tsocks to make your program use a socks proxy
		570	transparently.
		571
		572	Alternatively, for AnyEvent::HTTP only, you can use your own
		573	"tcp_connect" function that does the proxy handshake - here is an
		574	example that works with socks4a proxies:
		575
		576	use Errno;
		577	use AnyEvent::Util;
		578	use AnyEvent::Socket;
		579	use AnyEvent::Handle;
		580
		581	# host, port and username of/for your socks4a proxy
		582	my $socks_host = "10.0.0.23";
		583	my $socks_port = 9050;
		584	my $socks_user = "";
		585
		586	sub socks4a_connect {
		587	my ($host, $port, $connect_cb, $prepare_cb) = @_;
		588
		589	my $hdl = new AnyEvent::Handle
		590	connect => [$socks_host, $socks_port],
		591	on_prepare => sub { $prepare_cb->($_[0]{fh}) },
		592	on_error => sub { $connect_cb->() },
		593	;
		594
		595	$hdl->push_write (pack "CCnNZZ", 4, 1, $port, 1, $socks_user, $host);
		596
		597	$hdl->push_read (chunk => 8, sub {
		598	my ($hdl, $chunk) = @_;
		599	my ($status, $port, $ipn) = unpack "xCna4", $chunk;
		600
		601	if ($status == 0x5a) {
		602	$connect_cb->($hdl->{fh}, (format_address $ipn) . ":$port");
		603	} else {
		604	$! = Errno::ENXIO; $connect_cb->();
		605	}
		606	});
		607
		608	$hdl
		609	}
		610
		611	Use "socks4a_connect" instead of "tcp_connect" when doing
		612	"http_request"s, possibly after switching off other proxy types:
		613
		614	AnyEvent::HTTP::set_proxy undef; # usually you do not want other proxies
		615
		616	http_get 'http://www.google.com', tcp_connect => \&socks4a_connect, sub {
		617	my ($data, $headers) = @_;
		618	...
		619	};
279		620
280	SEE ALSO	621	SEE ALSO
281	AnyEvent.	622	AnyEvent.
282		623
283	AUTHOR	624	AUTHOR

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Comparing AnyEvent-HTTP/README (file contents): Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs. Revision 1.24 by root, Wed Nov 14 22:22:24 2012 UTC

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Comparing AnyEvent-HTTP/README (file contents):
Revision 1.12 by root, Sat Dec 5 15:37:07 2009 UTC vs.
Revision 1.24 by root, Wed Nov 14 22:22:24 2012 UTC