PHP supports libcurl, a library created by Daniel
Stenberg, that allows you to connect and communicate to
many different types of servers with many different
types of protocols. libcurl currently supports the
http, https, ftp, gopher, telnet, dict, file, and ldap
protocols. libcurl also supports HTTPS certificates,
HTTP POST, HTTP PUT, FTP uploading (this can also be
done with PHP's ftp extension), HTTP form based upload,
proxies, cookies, and user+password authentication.
These functions have been added in PHP 4.0.2.
In order to use the CURL functions you need to
install the CURL package. PHP requires that you use CURL
7.0.2-beta or higher. PHP will not work with any
version of CURL below version 7.0.2-beta. From PHP
version 4.2.3 you will atleast need CURL version 7.9.0
or higher.
To use PHP's CURL support you must also compile
PHP --with-curl[=DIR] where DIR
is the location of the directory containing the lib and
include directories. In the "include" directory there
should be a folder named "curl" which should contain
the easy.h and curl.h files. There should be a file
named libcurl.a located in
the "lib" directory. Beginning with PHP 4.3.0 you can
configure PHP to use CURL for url streams --with-curlwrappers.
Note to Win32 Users: In order to enable this module on a Windows environment, you must copy libeay32.dll and ssleay32.dll from the DLL folder of the PHP/Win32 binary package to the SYSTEM32 folder of your windows machine. (Ex: C:\WINNT\SYSTEM32 or C:\WINDOWS\SYSTEM32)
以下的常數由此延伸定義, 只在這個延伸被編譯成PHP或實行時期被動態載入時有效。
Once you've compiled PHP with CURL support, you
can begin using the CURL functions. The basic idea
behind the CURL functions is that you initialize a CURL
session using the curl_init(), then you can set
all your options for the transfer via the
curl_setopt(), then you can execute the session
with the curl_exec() and then you finish off
your session using the
curl_close(). Here is an example that uses the
CURL functions to fetch the example.com homepage into a
file: