docs/libcurl/libcurl.3 - third_party/curl - Git at Google

 .\" You can view this file with:
 .\" nroff -man [file]
 .\" $Id$
 .\"
 .TH libcurl 3 "19 March 2002" "libcurl 7.9.6" "libcurl overview"
 .SH NAME
 libcurl \- client-side URL transfers
 .SH DESCRIPTION
 This is an overview on how to use libcurl in your C programs. There are
 specific man pages for each function mentioned in here. There are also the
 \fIlibcurl-easy\fP man page, the \fIlibcurl-multi\fP man page, the
 \fIlibcurl-share\fP man page and the \fIlibcurl-the-guide\fP document for
 further reading on how to do programming with libcurl.

 There exist more than a dozen custom bindings that bring libcurl access to
 your favourite language. Look elsewhere for documentation on those.

 All applications that use libcurl should call \fIcurl_global_init()\fP exactly
 once before any libcurl function can be used. After all usage of libcurl is
 complete, it \fBmust\fP call \fIcurl_global_cleanup()\fP. In between those two
 calls, you can use libcurl as described below.

 To transfer files, you always set up an "easy handle" using
 \fIcurl_easy_init()\fP, but when you want the file(s) transfered you have the
 option of using the "easy" interface, or the "multi" interface.

 The easy interface is a synchronous interface with which you call
 \fIcurl_easy_perform\fP and let it perform the transfer. When it is completed,
 the function return and you can continue. More details are found in the
 \fIlibcurl-easy\fP man page.

 The multi interface on the other hand is an asynchronous interface, that you
 call and that performs only a little piece of the tranfer on each invoke. It
 is perfect if you want to do things while the transfer is in progress, or
 similar. The multi interface allows you to select() on libcurl action, and
 even to easily download multiple files simultaneously using a single thread.

 You can have multiple easy handles share certain data, even if they are used
 in different threads. This magic is setup using the share interface, as
 described in the \fIlibcurl-share\fP man page.

 There is also a series of other helpful functions to use. They are:

 .RS
 .TP 10
 .B curl_version()
 displays the libcurl version
 .TP
 .B curl_getdate()
 converts a date string to time_t
 .TP
 .B curl_getenv()
 portable environment variable reader
 .TP
 .B curl_easy_getinfo()
 get information about a performed transfer
 .TP
 .B curl_formadd()
 helps building a HTTP form POST
 .TP
 .B curl_formfree()
 free a list built with curl_formparse()/curl_formadd()
 .TP
 .B curl_slist_append()
 builds a linked list
 .TP
 .B curl_slist_free_all()
 frees a whole curl_slist
 .TP
 .B curl_mprintf()
 portable printf() functions
 .TP
 .B curl_strequal()
 portable case insensitive string comparisons
 .RE

 .SH "LINKING WITH LIBCURL"
 On unix-like machines, there's a tool named curl-config that gets installed
 with the rest of the curl stuff when 'make install' is performed.

 curl-config is added to make it easier for applications to link with libcurl
 and developers to learn about libcurl and how to use it.

 Run 'curl-config --libs' to get the (additional) linker options you need to
 link with the particular version of libcurl you've installed.

 For details, see the curl-config.1 man page.
 .SH "LIBCURL SYMBOL NAMES"
 All public functions in the libcurl interface are prefixed with 'curl_' (with
 a lowercase c). You can find other functions in the library source code, but
 other prefixes indicate the functions are private and may change without
 further notice in the next release.

 Only use documented functions and functionality!
 .SH "PORTABILITY"
 libcurl works
 .B exactly
 the same, on any of the platforms it compiles and builds on.
 .SH "THREADS"
 Never ever call curl-functions simultaneously using the same handle from
 several threads. libcurl is thread-safe and can be used in any number of
 threads, but you must use separate curl handles if you want to use libcurl in
 more than one thread simultaneously.
 .SH "PERSISTANT CONNECTIONS"
 Persistent connections means that libcurl can re-use the same connection for
 several transfers, if the conditions are right.

 libcurl will *always* attempt to use persistent connections. Whenever you use
 \fIcurl_easy_perform()\fP or \fIcurl_multi_perform()\fP, libcurl will attempt
 to use an existing connection to do the transfer, and if none exists it'll
 open a new one that will be subject for re-use on a possible following call to
 \fIcurl_easy_perform()\fP or \fIcurl_multi_perform()\fP.

 To allow libcurl to take full advantage of persistent connections, you should
 do as many of your file transfers as possible using the same curl handle. When
 you call \fIcurl_easy_cleanup()\fP, all the possibly open connections held by
 libcurl will be closed and forgotten.

 Note that the options set with \fIcurl_easy_setopt()\fP will be used in on
 every repeated \fIcurl_easy_perform()\fP call.
	.\" You can view this file with:
	.\" nroff -man [file]
	.\" $Id$
	.\"
	.TH libcurl 3 "19 March 2002" "libcurl 7.9.6" "libcurl overview"
	.SH NAME
	libcurl \- client-side URL transfers
	.SH DESCRIPTION
	This is an overview on how to use libcurl in your C programs. There are
	specific man pages for each function mentioned in here. There are also the
	\fIlibcurl-easy\fP man page, the \fIlibcurl-multi\fP man page, the
	\fIlibcurl-share\fP man page and the \fIlibcurl-the-guide\fP document for
	further reading on how to do programming with libcurl.

	There exist more than a dozen custom bindings that bring libcurl access to
	your favourite language. Look elsewhere for documentation on those.

	All applications that use libcurl should call \fIcurl_global_init()\fP exactly
	once before any libcurl function can be used. After all usage of libcurl is
	complete, it \fBmust\fP call \fIcurl_global_cleanup()\fP. In between those two
	calls, you can use libcurl as described below.

	To transfer files, you always set up an "easy handle" using
	\fIcurl_easy_init()\fP, but when you want the file(s) transfered you have the
	option of using the "easy" interface, or the "multi" interface.

	The easy interface is a synchronous interface with which you call
	\fIcurl_easy_perform\fP and let it perform the transfer. When it is completed,
	the function return and you can continue. More details are found in the
	\fIlibcurl-easy\fP man page.

	The multi interface on the other hand is an asynchronous interface, that you
	call and that performs only a little piece of the tranfer on each invoke. It
	is perfect if you want to do things while the transfer is in progress, or
	similar. The multi interface allows you to select() on libcurl action, and
	even to easily download multiple files simultaneously using a single thread.

	You can have multiple easy handles share certain data, even if they are used
	in different threads. This magic is setup using the share interface, as
	described in the \fIlibcurl-share\fP man page.

	There is also a series of other helpful functions to use. They are:

	.RS
	.TP 10
	.B curl_version()
	displays the libcurl version
	.TP
	.B curl_getdate()
	converts a date string to time_t
	.TP
	.B curl_getenv()
	portable environment variable reader
	.TP
	.B curl_easy_getinfo()
	get information about a performed transfer
	.TP
	.B curl_formadd()
	helps building a HTTP form POST
	.TP
	.B curl_formfree()
	free a list built with curl_formparse()/curl_formadd()
	.TP
	.B curl_slist_append()
	builds a linked list
	.TP
	.B curl_slist_free_all()
	frees a whole curl_slist
	.TP
	.B curl_mprintf()
	portable printf() functions
	.TP
	.B curl_strequal()
	portable case insensitive string comparisons
	.RE

	.SH "LINKING WITH LIBCURL"
	On unix-like machines, there's a tool named curl-config that gets installed
	with the rest of the curl stuff when 'make install' is performed.

	curl-config is added to make it easier for applications to link with libcurl
	and developers to learn about libcurl and how to use it.

	Run 'curl-config --libs' to get the (additional) linker options you need to
	link with the particular version of libcurl you've installed.

	For details, see the curl-config.1 man page.
	.SH "LIBCURL SYMBOL NAMES"
	All public functions in the libcurl interface are prefixed with 'curl_' (with
	a lowercase c). You can find other functions in the library source code, but
	other prefixes indicate the functions are private and may change without
	further notice in the next release.

	Only use documented functions and functionality!
	.SH "PORTABILITY"
	libcurl works
	.B exactly
	the same, on any of the platforms it compiles and builds on.
	.SH "THREADS"
	Never ever call curl-functions simultaneously using the same handle from
	several threads. libcurl is thread-safe and can be used in any number of
	threads, but you must use separate curl handles if you want to use libcurl in
	more than one thread simultaneously.
	.SH "PERSISTANT CONNECTIONS"
	Persistent connections means that libcurl can re-use the same connection for
	several transfers, if the conditions are right.

	libcurl will always attempt to use persistent connections. Whenever you use
	\fIcurl_easy_perform()\fP or \fIcurl_multi_perform()\fP, libcurl will attempt
	to use an existing connection to do the transfer, and if none exists it'll
	open a new one that will be subject for re-use on a possible following call to
	\fIcurl_easy_perform()\fP or \fIcurl_multi_perform()\fP.

	To allow libcurl to take full advantage of persistent connections, you should
	do as many of your file transfers as possible using the same curl handle. When
	you call \fIcurl_easy_cleanup()\fP, all the possibly open connections held by
	libcurl will be closed and forgotten.

	Note that the options set with \fIcurl_easy_setopt()\fP will be used in on
	every repeated \fIcurl_easy_perform()\fP call.