PHP CURL CURLOPT parameter description (curl_setopt)_PHP tutorial

CURLOPT_RETURNTRANSFER 选项：

curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);

如果成功只将结果返回，不自动输出任何内容。

如果失败返回FALSE

curl_setopt($ch, CURLOPT_RETURNTRANSFER,0); 或着不使用这个选项：

如果成功只返回TRUE，自动输出返回的内容。

如果失败返回FALSE

PHP中CURL方法curl_setopt()函数的一些参数 .

bool curl_setopt (int ch, string option, mixed value)
curl_setopt()函数将为一个CURL会话设置选项。option参数是你想要的设置，value是这个选项给定的值。

下列选项的值将被作为长整形使用(在option参数中指定)：   
•    CURLOPT_INFILESIZE : 当你上传一个文件到远程站点，这个选项告诉PHP你上传文件的大小。
•    CURLOPT_VERBOSE : 如果你想CURL报告每一件意外的事情，设置这个选项为一个非零值。
•    CURLOPT_HEADER : 如果你想把一个头包含在输出中，设置这个选项为一个非零值。
•    CURLOPT_NOPROGRESS: 如果你不会PHP为CURL传输显示一个进程条，设置这个选项为一个非零值。注意：PHP自动设置这个选项为非零值，你应该仅仅为了调试的目的来改变这个选项。
•    CURLOPT_NOBODY : 如果你不想在输出中包含body部分，设置这个选项为一个非零值。
•    CURLOPT_FAILONERROR : 如果你想让PHP在发生错误(HTTP代码返回大于等于300)时，不显示，设置这个选项为一人非零值。默认行为是返回一个正常页，忽略代码。
•    CURLOPT_UPLOAD: 如果你想让PHP为上传做准备，设置这个选项为一个非零值。
•    CURLOPT_POST : 如果你想PHP去做一个正规的HTTP POST，设置这个选项为一个非零值。这个POST是普通的 application/x-www-from-urlencoded 类型，多数被HTML表单使用。
•    CURLOPT_FTPLISTONLY : 设置这个选项为非零值，PHP将列出FTP的目录名列表。
•    CURLOPT_FTPAPPEND : 设置这个选项为一个非零值，PHP将应用远程文件代替覆盖它。
•    CURLOPT_NETRC : 设置这个选项为一个非零值，PHP将在你的 ~./netrc 文件中查找你要建立连接的远程站点的用户名及密码。
•    CURLOPT_FOLLOWLOCATION : 设置这个选项为一个非零值(象 “Location: “)的头，服务器会把它当做HTTP头的一部分发送(注意这是递归的，PHP将发送形如 “Location: “的头)。
•    CURLOPT_PUT : 设置这个选项为一个非零值去用HTTP上传一个文件。要上传这个文件必须设置CURLOPT_INFILE和CURLOPT_INFILESIZE选项.
•    CURLOPT_MUTE : 设置这个选项为一个非零值，PHP对于CURL函数将完全沉默。
•    CURLOPT_TIMEOUT : 设置一个长整形数，作为最大延续多少秒。
•    CURLOPT_LOW_SPEED_LIMIT: 设置一个长整形数，控制传送多少字节。
•    CURLOPT_LOW_SPEED_TIME : 设置一个长整形数，控制多少秒传送CURLOPT_LOW_SPEED_LIMIT规定的字节数。
•    CURLOPT_RESUME_FROM : 传递一个包含字节偏移地址的长整形参数，(你想转移到的开始表单)。
•    CURLOPT_SSLVERSION: 传递一个包含SSL版本的长参数。默认PHP将被它自己努力的确定，在更多的安全中你必须手工设置。
•    CURLOPT_TIMECONDITION : 传递一个长参数，指定怎么处理CURLOPT_TIMEVALUE参数。你可以设置这个参数为TIMECOND_IFMODSINCE 或 TIMECOND_ISUNMODSINCE。这仅用于HTTP。
•    CURLOPT_TIMEVALUE : 传递一个从1970-1-1开始到现在的秒数。这个时间将被CURLOPT_TIMEVALUE选项作为指定值使用，或被默认TIMECOND_IFMODSINCE使用。

The values ​​of the following options will be treated as strings:
• CURLOPT_URL: This is the URL address you want to retrieve using PHP. You can also set this option during initialization with the curl_init() function.
• CURLOPT_USERPWD: Pass a string in the form of [username]:[password] and use PHP to connect.
• CURLOPT_PROXYUSERPWD: Pass a string in the format [username]:[password] to connect to the HTTP proxy.
• CURLOPT_RANGE : Pass a range you want to specify. It should be in "X-Y" format, with X or Y being excluded. HTTP transfers also support several intervals, separated by commas (X-Y,N-M).
• CURLOPT_POSTFIELDS : Pass a string containing all the data as an HTTP "POST" operation.
• CURLOPT_REFERER: A string containing a "referer" header in the HTTP request.
• CURLOPT_USERAGENT: A string containing a "user-agent" header in the HTTP request.
• CURLOPT_FTPPORT: Pass an IP address containing the IP address used by the ftp "POST" command. This POST command tells the remote server to connect to the IP address we specified. This string can be an IP address, a host name, a network interface name (under UNIX), or '-' (use the system default IP address).
• CURLOPT_COOKIE: Pass a header connection containing an HTTP cookie.
• CURLOPT_SSLCERT : Pass a string containing the certificate in PEM format.
• CURLOPT_SSLCERTPASSWD: Pass a password containing the necessary password to use the CURLOPT_SSLCERT certificate.
• CURLOPT_COOKIEFILE: Pass a string containing the name of the file containing cookie data. This cookie file can be in Netscape format, or it can be a stack of HTTP-style headers stored in the file.
• CURLOPT_CUSTOMREQUEST: When making an HTTP request, pass a character to be used by GET or HEAD. Pass a string to be used instead of GET or HEAD when doing an HTTP request. This is useful for doing or another, more obscure, HTTP request. Note: Make sure your server supports Order not to do it yet. The following options require a file description (obtained by using the fopen() function):
• CURLOPT_FILE: This file will be the output file you place the transfer. The default is STDOUT.
• CURLOPT_INFILE: This file will be the output file you transfer. input file.
• CURLOPT_WRITEHEADER: This file contains the header part of your output.
• CURLOPT_STDERR : This file has errors written instead of stderr. An example of obtaining a page that requires login. The current method is to log in once every time. People who need it will make improvements.

Example 1:

Example 2:

Example 3:

刷论坛代码：
1、抓cookies程序：

2、刷楼了：

curl_close — close a curl session
curl_copy_handle — copy all contents and parameters of a curl connection resource
curl_errno — return a numeric number containing the current session error message
curl_error — return a numeric number containing the current session error message String of information
curl_exec — Execute a curl session
curl_getinfo — Get information about a curl connection resource handle
curl_init — Initialize a curl session
curl_multi_add_handle — Add individual curls to a curl batch session Handle resource
curl_multi_close — Close a batch handle resource
curl_multi_exec — Parse a curl batch handle
curl_multi_getcontent — Return the text stream of the obtained output
curl_multi_info_read — Get the relevant transmission information of the currently parsed curl
curl_multi_init — Initialize a curl batch handle resource
curl_multi_remove_handle — Remove a handle resource in the curl batch handle resource
curl_multi_select — Get all the sockets associated with the cURL extension, which can then be " selected"
curl_setopt_array — Set session parameters for a curl in the form of an array
curl_setopt — Set session parameters for a curl
curl_version — Get curl-related version information
The role of the curl_init() function is to initialize a Curl session, the only parameter of the curl_init() function is optional and represents a URL address.
The curl_exec() function is used to execute a curl session. The only parameter is the handle returned by the curl_init() function.
The curl_close() function is used to close a curl session. The only parameter is the handle returned by the curl_init() function.

$ch = curl_init("http://www.baidu.com/");
curl_exec($ch);
curl_close($ch);
curl_version() function is Get curl-related version information. The curl_version() function has a parameter. It’s not clear what it does

print_r(curl_version())
The role of the curl_getinfo() function is to obtain information about a curl connection resource handle. The curl_getinfo() function has two parameters. The first parameter is the curl resource handle, and the second The parameters are the following constants:

$ch = curl_init("http://www.baidu.com/");
print_r(curl_getinfo($ch));
Optional constants include:
CURLINFO_EFFECTIVE_URL
The last valid url address
CURLINFO_HTTP_CODE
The last HTTP code received
CURLINFO_FILETIME
The time to remotely obtain the document. If it cannot be obtained, the return value is "-1"
CURLINFO_TOTAL_TIME
Time spent on the last transfer
CURLINFO_NAMELOOKUP_TIME
Time spent on name resolution
CURLINFO_CONNECT_TIME
Time spent establishing the connection
CURLINFO_PRETRANSFER_TIME
Time spent from establishing the connection to preparing for the transfer The time
CURLINFO_STARTTRANSFER_TIME
The time taken from establishing the connection to the start of the transfer
CURLINFO_REDIRECT_TIME
The time taken to redirect before the transaction transfer starts
CURLINFO_SIZE_UPLOAD
The total amount of uploaded data
CURLINFO_SIZE_DOWNLOAD
Total value of downloaded data
CURLINFO_SPEED_DOWNLOAD
Average download speed
CURLINFO_SPEED_UPLOAD
Average upload speed
CURLINFO_HEADER_SIZE
Size of the header part
CURLIN FO_HEADER_OUT
Send requested string
CURLINFO_REQUEST_SIZE
The requested size in question in the HTTP request
CURLINFO_SSL_VERIFYRESULT
Result of SSL certification verification requested by setting CURLOPT_SSL_VERIFYPEER
CURLINFO_CONTENT_LENGTH_DOWNLOAD
From Content -Length : Download content length read in field
CURLINFO_CONTENT_LENGTH_UPLOAD
Description of upload content size
CURLINFO_CONTENT_TYPE

The "Content-type" value of the downloaded content, NULL means that the server did not send a valid "Content-Type: header"

The curl_setopt() function is used to set session parameters for a curl. The curl_setopt_array() function is used to set session parameters for a curl in the form of an array.

可设置的参数有：
CURLOPT_AUTOREFERER
自动设置header中的referer信息
CURLOPT_BINARYTRANSFER
在启用CURLOPT_RETURNTRANSFER时候将获取数据返回
CURLOPT_COOKIESESSION
启用时curl会仅仅传递一个session cookie，忽略其他的cookie，默认状况下curl会将所有的cookie返回给服务端。session cookie是指那些用来判断服务器端的session是否有效而存在的cookie。
CURLOPT_CRLF
启用时将Unix的换行符转换成回车换行符。
CURLOPT_DNS_USE_GLOBAL_CACHE
启用时会启用一个全局的DNS缓存，此项为线程安全的，并且默认为true。
CURLOPT_FAILONERROR
显示HTTP状态码，默认行为是忽略编号小于等于400的HTTP信息
CURLOPT_FILETIME
启用时会尝试修改远程文档中的信息。结果信息会通过curl_getinfo()函数的CURLINFO_FILETIME选项返回。
CURLOPT_FOLLOWLOCATION
启用时会将服务器服务器返回的“Location:”放在header中递归的返回给服务器，使用CURLOPT_MAXREDIRS可以限定递归返回的数量。
CURLOPT_FORBID_REUSE
在完成交互以后强迫断开连接，不能重用。
CURLOPT_FRESH_CONNECT
强制获取一个新的连接，替代缓存中的连接。
CURLOPT_FTP_USE_EPRT
TRUE to use EPRT (and LPRT) when doing active FTP downloads. Use FALSE to disable EPRT and LPRT and use PORT only.
Added in PHP 5.0.0.
CURLOPT_FTP_USE_EPSV
TRUE to first try an EPSV command for FTP transfers before reverting back to PASV. Set to FALSE to disable EPSV.
CURLOPT_FTPAPPEND
TRUE to append to the remote file instead of overwriting it.
CURLOPT_FTPASCII
An alias of CURLOPT_TRANSFERTEXT. Use that instead.
CURLOPT_FTPLISTONLY
TRUE to only list the names of an FTP directory.
CURLOPT_HEADER
启用时会将头文件的信息作为数据流输出。
CURLOPT_HTTPGET
启用时会设置HTTP的method为GET，因为GET是默认是，所以只在被修改的情况下使用。
CURLOPT_HTTPPROXYTUNNEL
启用时会通过HTTP代理来传输。
CURLOPT_MUTE
讲curl函数中所有修改过的参数恢复默认值。
CURLOPT_NETRC
在连接建立以后，访问~/.netrc文件获取用户名和密码信息连接远程站点。
CURLOPT_NOBODY
启用时将不对HTML中的body部分进行输出。
CURLOPT_NOPROGRESS
启用时关闭curl传输的进度条，此项的默认设置为true
CURLOPT_NOSIGNAL
启用时忽略所有的curl传递给php进行的信号。在SAPI多线程传输时此项被默认打开。
CURLOPT_POST
启用时会发送一个常规的POST请求，类型为：application/x-www-form-urlencoded，就像表单提交的一样。
CURLOPT_PUT
启用时允许HTTP发送文件，必须同时设置CURLOPT_INFILE和CURLOPT_INFILESIZE
CURLOPT_RETURNTRANSFER
讲curl_exec()获取的信息以文件流的形式返回，而不是直接输出。
CURLOPT_SSL_VERIFYPEER
FALSE to stop cURL from verifying the peer's certificate. Alternate certificates to verify against can be specified with the CURLOPT_CAINFO option or a certificate directory can be specified with the CURLOPT_CAPATH option. CURLOPT_SSL_VERIFYHOST may also need to be TRUE or FALSE if CURLOPT_SSL_VERIFYPEER is disabled (it defaults to 2). TRUE by default as of cURL 7.10. Default bundle installed as of cURL 7.10.
CURLOPT_TRANSFERTEXT
TRUE to use ASCII mode for FTP transfers. For LDAP, it retrieves data in plain text instead of HTML. On Windows systems, it will not set STDOUT to binary mode.
CURLOPT_UNRESTRICTED_AUTH
在使用CURLOPT_FOLLOWLOCATION产生的header中的多个locations中持续追加用户名和密码信息，即使域名已发生改变。
CURLOPT_UPLOAD
启用时允许文件传输
CURLOPT_VERBOSE
启用时会汇报所有的信息，存放在STDERR或指定的CURLOPT_STDERR中
CURLOPT_BUFFERSIZE
每次获取的数据中读入缓存的大小，这个值每次都会被填满。
CURLOPT_CLOSEPOLICY
不是CURLCLOSEPOLICY_LEAST_RECENTLY_USED就是CURLCLOSEPOLICY_OLDEST，还存在另外三个，但是curl暂时还不支持。.
CURLOPT_CONNECTTIMEOUT
在发起连接前等待的时间，如果设置为0，则不等待。
CURLOPT_DNS_CACHE_TIMEOUT
设置在内存中保存DNS信息的时间，默认为120秒。
CURLOPT_FTPSSLAUTH
The FTP authentication method (when is activated): CURLFTPAUTH_SSL (try SSL first), CURLFTPAUTH_TLS (try TLS first), or CURLFTPAUTH_DEFAULT (let cURL decide).
CURLOPT_HTTP_VERSION
设置curl使用的HTTP协议，CURL_HTTP_VERSION_NONE（让curl自己判断），CURL_HTTP_VERSION_1_0（HTTP/1.0），CURL_HTTP_VERSION_1_1（HTTP/1.1）

CURLOPT_HTTPAUTH

使用的HTTP验证方法，可选的值 有：CURLAUTH_BASIC，CURLAUTH_DIGEST，CURLAUTH_GSSNEGOTIATE，CURLAUTH_NTLM，CURLAUTH_ANY，CURLAUTH_ANYSAFE， 可以使用“|”操作符分隔多个值，curl让服务器选择一个支持最好的值，CURLAUTH_ANY等价于CURLAUTH_BASIC | CURLAUTH_DIGEST | CURLAUTH_GSSNEGOTIATE | CURLAUTH_NTLM，CURLAUTH_ANYSAFE等价于CURLAUTH_DIGEST | CURLAUTH_GSSNEGOTIATE | CURLAUTH_NTLM
CURLOPT_INFILESIZE

设定上传文件的大小

CURLOPT_LOW_SPEED_LIMIT
When the transmission speed is less than CURLOPT_LOW_SPEED_LIMIT, PHP will use CURLOPT_LOW_SPEED_TIME to determine whether to cancel the transmission because it is too slow.
CURLOPT_LOW_SPEED_TIME
The number of seconds the transfer should be below CURLOPT_LOW_SPEED_LIMIT for PHP to consider the transfer too slow and abort. transmission.
CURLOPT_MAXCONNECTS
The maximum number of connections allowed. If exceeded, CURLOPT_CLOSEPOLICY will be used to determine which connections should be stopped.
CURLOPT_MAXREDIRS
Specify the maximum number of HTTP redirects. This option is used together with CURLOPT_FOLLOWLOCATION. For proxy authentication, only CURLAUTH_BASIC and CURLAUTH_NTLM are currently supported.
CURLOPT_PROXYPORT
The port number of the proxy to connect to. This port number can also be set in CURLOPT_PROXY. CURLPROXY_SOCKS5.
CURLOPT_RESUME_FROM
Pass a byte offset when resuming the transfer (used to resume the transfer)
CURLOPT_SSL_VERIFYHOST
1 to check the existence of a common name in the SSL peer certificate.
2 to check the existence of a common name and also verify that it matches the hostname provided.
CURLOPT_SSLVERSION
The SSL version (2 or 3) to use. By default PHP will try to determine this itself, although in some cases this must be set manually.
CURLOPT_TIMECONDITION
If it has been edited after a certain time specified by CURLOPT_TIMEVALUE, use CURL_TIMECOND_IFMODSINCE to return the page, if it has not been modified and CURLOPT_HEADER is true, return a "304 Not Modified" header, if CURLOPT_HEADER is false, use CURL_TIMECOND_ISUNMODSINCE, the default value is CURL_TIMECOND_IFMODSINCE
CURLOPT_TIMEOUT
Set the maximum number of seconds that curl is allowed to execute
CURLOPT_TIMEVALUE
Set the time used by CURLOPT_TIMECONDITION poke , used by default is CURL_TIMECOND_IFMODSINCE
CURLOPT_CAINFO
The name of a file holding one or more certificates to verify the peer with. This only makes sense when used in combination with CURLOPT_SSL_VERIFYPEER.
CURLOPT_CAPATH
A directory that holds multiple CA certificates. Use this option alongside CURLOPT_SSL_VERIFYPEER.
CURLOPT_COOKIE
Set the content of the "Set-Cookie:" part of the HTTP request.
CURLOPT_COOKIEFILE
The name of the file containing cookie information. This cookie file can be Netscape format or HTTP style header information.
CURLOPT_COOKIEJAR
After the connection is closed, the name of the file to store cookie information
CURLOPT_CUSTOMREQUEST
A custom request method to use instead of "GET" or "HEAD" when doing a HTTP request. This is useful for doing "DELETE" or other, more obscure HTTP requests. Valid values ​​are things like "GET", "POST", "CONNECT" and so on; i.e. Do not enter a whole HTTP request line here. For instance, entering "GET /index .html HTTP/1.0rnrn" would be incorrect.
Note: Don't do this without making sure the server supports the custom request method first.
CURLOPT_EGBSOCKET
Like CURLOPT_RANDOM_FILE, except a filename to an Entropy Gathering Daemon socket.
CURLOPT_ENCODING
The contents of the "Accept-Encoding:" part of the header. The supported encoding formats are: "identity", "deflate", "gzip". If set to an empty string, it means that all encoding formats are supported
CURLOPT_FTPPORT
The value which will be used to get the IP address to use for the FTP "POST" instruction. The "POST" instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a hostname, a network interface name (under Unix), or just a plain '-' to use the systems default IP address.
CURLOPT_INTERFACE
The name used in the external network interface, which can be an interface name, IP or host name.
CURLOPT_KRB4LEVEL
KRB4 (Kerberos 4) security level setting, which can be one of the following values: "clear", "safe", "confidential", "private". The default value is "private". When set to null, it means KRB4 is disabled. Now KRB4 security can only be used in FTP transmission.
CURLOPT_POSTFIELDS
The "POST" operation in HTTP. If you want to transfer a file, you need a file name starting with @
CURLOPT_PROXY
Set the HTTP proxy server through
CURLOPT_PROXYUSERPWD
to connect to the proxy server, the format is "[username]:[password]" username and password.
CURLOPT_RANDOM_FILE
Set the file name to store the random number seeds used by SSL
CURLOPT_RANGE
Set the HTTP transmission range. You can set a transmission range in the form of "X-Y". If there are multiple HTTP transmissions , use commas to separate multiple values, such as: "X-Y,N-M".
CURLOPT_REFERER
Set the value of the "Referer: " part in the header.
CURLOPT_SSL_CIPHER_LIST
A list of ciphers to use for SSL. For example, RC4-SHA and TLSv1 are valid cipher lists.
CURLOPT_SSLCERT
传递一个包含PEM格式证书的字符串。
CURLOPT_SSLCERTPASSWD
传递一个包含使用CURLOPT_SSLCERT证书必需的密码。
CURLOPT_SSLCERTTYPE
The format of the certificate. Supported formats are "PEM" (default), "DER", and "ENG".
CURLOPT_SSLENGINE
The identifier for the crypto engine of the private SSL key specified in CURLOPT_SSLKEY.
CURLOPT_SSLENGINE_DEFAULT
The identifier for the crypto engine used for asymmetric crypto operations.
CURLOPT_SSLKEY
The name of a file containing a private SSL key.
CURLOPT_SSLKEYPASSWD
The secret password needed to use the private SSL key specified in CURLOPT_SSLKEY.
Note: Since this option contains a sensitive password, remember to keep the PHP script it is contained within safe.
CURLOPT_SSLKEYTYPE
The key type of the private SSL key specified in CURLOPT_SSLKEY. Supported key types are "PEM" (default), "DER", and "ENG".
CURLOPT_URL
需要获取的URL地址，也可以在PHP的curl_init()函数中设置。
CURLOPT_USERAGENT
在HTTP请求中包含一个”user-agent”头的字符串。
CURLOPT_USERPWD
传递一个连接中需要的用户名和密码，格式为：“[username]:[password]”。
CURLOPT_HTTP200ALIASES
设置不再以error的形式来处理HTTP 200的响应，格式为一个数组。
CURLOPT_HTTPHEADER
设置一个header中传输内容的数组。
CURLOPT_POSTQUOTE
An array of FTP commands to execute on the server after the FTP request has been performed.
CURLOPT_QUOTE
An array of FTP commands to execute on the server prior to the FTP request.
CURLOPT_FILE
设置输出文件的位置，值是一个资源类型，默认为STDOUT (浏览器)。
CURLOPT_INFILE
在上传文件的时候需要读取的文件地址，值是一个资源类型。
CURLOPT_STDERR
设置一个错误输出地址，值是一个资源类型，取代默认的STDERR。
CURLOPT_WRITEHEADER
设置header部分内容的写入的文件地址，值是一个资源类型。
CURLOPT_HEADERFUNCTION
设置一个回调函数，这个函数有两个参数，第一个是curl的资源句柄，第二个是输出的header数据。header数据的输出必须依赖这个函数，返回已写入的数据大小。
CURLOPT_PASSWDFUNCTION
设置一个回调函数，有三个参数，第一个是curl的资源句柄，第二个是一个密码提示符，第三个参数是密码长度允许的最大值。返回密码的值。
CURLOPT_READFUNCTION
设置一个回调函数，有两个参数，第一个是curl的资源句柄，第二个是读取到的数据。数据读取必须依赖这个函数。返回读取数据的大小，比如0或者EOF。
CURLOPT_WRITEFUNCTION
设置一个回调函数，有两个参数，第一个是curl的资源句柄，第二个是写入的数据。数据写入必须依赖这个函数。返回精确的已写入数据的大小

curl_copy_handle()函数的作用是拷贝一个curl连接资源的所有内容和参数

$ch = curl_init("http://www.baidu.com/");
$another = curl_copy_handle($ch);
curl_exec($another);
curl_close($another);
curl_error()函数的作用是返回一个包含当前会话错误信息的字符串。
curl_errno()函数的作用是返回一个包含当前会话错误信息的数字编号。
curl_multi_init()函数的作用是初始化一个curl批处理句柄资源。
curl_multi_add_handle()函数的作用是向curl批处理会话中添加单独的curl句柄资源。curl_multi_add_handle()函数有两个参数，第一个参数表示一个curl批处理句柄资源，第二个参数表示一个单独的curl句柄资源。
curl_multi_exec()函数的作用是解析一个curl批处理句柄，curl_multi_exec()函数有两个参数，第一个参数表示一个批处理句柄资源，第二个参数是一个引用值的参数，表示剩余需要处理的单个的curl句柄资源数量。
curl_multi_remove_handle()函数表示移除curl批处理句柄资源中的某个句柄资源，curl_multi_remove_handle()函数有两个参数，第一个参数表示一个curl批处理句柄资源，第二个参数表示一个单独的curl句柄资源。
curl_multi_close()函数的作用是关闭一个批处理句柄资源。

$ch1 = curl_init();
$ch2 = curl_init();
curl_setopt($ch1, CURLOPT_URL, "http://www.baidu.com/");
curl_setopt($ ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.google.com/");
curl_setopt($ch2, CURLOPT_HEADER, 0);
$mh = curl_multi_init();
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
do {
curl_multi_exec($mh,$flag);
} while ($flag > 0);
curl_multi_remove_handle($mh,$ch1);
curl_multi_remove_handle($mh,$ch2);
curl_multi_close($mh);
The role of curl_multi_getcontent() function Returns the text stream of the obtained output when CURLOPT_RETURNTRANSFER is set.
The curl_multi_info_read() function is used to obtain the relevant transmission information of the currently parsed curl.
curl_multi_select()
Get all the sockets associated with the cURL extension, which can then be "selected"