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diff --git a/docs/libcurl.5 b/docs/libcurl.5 new file mode 100644 index 000000000..84ceff380 --- /dev/null +++ b/docs/libcurl.5 @@ -0,0 +1,124 @@ +.\" You can view this file with: +.\" nroff -man libcurl.5 +.\" Written by Daniel Stenberg +.\" +.TH libcurl 5 "20 April 2001" "libcurl 7.7.2" "libcurl overview" +.SH NAME +libcurl \- client-side URL transfers +.SH DESCRIPTION +This is an overview on how to use libcurl in your c/c++ programs. There are +specific man pages for each function mentioned in here. + +libcurl can also be used directly from within your Java, PHP, Perl, Ruby or +Tcl programs as well, look elsewhere for documentation on this! + +When using libcurl's easy interface, you init your session and get a handle, +which you use as input to the following interface functions you use. Use +.B curl_easy_init() +to get the handle. + +You continue by setting all the options you want in the upcoming transfer, +most important among them is the URL itself (you can't transfer anything +without a specified URL as you may have figured out yourself). You might want +to set some callbacks as well that will be called from the library when data +is available etc. +.B curl_easy_setopt() +is there for this. + +When all is setup, you tell libcurl to perform the transfer using +.B curl_easy_perform(). +It will then do the entire operation and won't return until it is done +(successfully or not). + +After the transfer has been made, you can set new options and make another +transfer, or if you're done, cleanup the session by calling +.B curl_easy_cleanup(). +If you want persistant connections, you don't cleanup immediately, but instead +run ahead and perform other transfers using the same handle. See the chapter +below for Persistant Connections. + +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_formparse() +helps building a HTTP form POST +.TP +.B curl_formfree() +free a list built with curl_formparse() +.TP +.B curl_slist_append() +builds a linked list +.TP +.B curl_slist_free_all() +frees a whole curl_slist +.RE + +.SH "LINKING WITH LIBCURL" +Starting with 7.7.2 (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. + +There's only one caution, and that is the win32 platform that may(*) require +you to init the winsock stuff before you use the libcurl functions. Details on +this are noted on the curl_easy_init() man page. + +(*) = it appears as if users of the cygwin environment get this done +automatically. +.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" +With libcurl 7.7, persistant connections were added. Persistant connections +means that libcurl can re-use the same connection for several transfers, if +the conditions are right. + +libcurl will *always* attempt to use persistant connections. Whenever you use +curl_easy_perform(), 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 curl_easy_perform(). + +To allow libcurl to take full advantage of persistant connections, you should +do as many of your file transfers as possible using the same curl +handle. When you call curl_easy_cleanup(), all the possibly open connections +held by libcurl will be closed and forgotten. + +Note that the options set with curl_easy_setopt() will be used in on every +repeat curl_easy_perform() call +.SH "COMPATIBILITY WITH OLDER LIBCURLS" +Repeated curl_easy_perform() calls on the same handle were not supported in +pre-7.7 versions, and caused confusion and defined behaviour. + |