curl_easy_setopt.html

专门介绍网络爬虫设计的论文,写得非常好啊.希望大家好好学习

<p class="level1">Pass a pointer to a zero terminated string as parameter. It will be used to set the User-Agent: header in the http request sent to the remote server. This can be used to fool servers or scripts. You can also set any custom header with <a class="emphasis" href="#CURLOPTHTTPHEADER">CURLOPT_HTTPHEADER</a>. 
<p class="level0"><a name="CURLOPTHTTPHEADER"></a><span class="nroffip">CURLOPT_HTTPHEADER</span> 
<p class="level1">Pass a pointer to a linked list of HTTP headers to pass to the server in your HTTP request. The linked list should be a fully valid list of <span class="bold">struct curl_slist</span> structs properly filled in. Use <a class="emphasis" href="./curl_slist_append.html">curl_slist_append(3)</a> to create the list and <a class="emphasis" href="./curl_slist_free_all.html">curl_slist_free_all(3)</a> to clean up an entire list. If you add a header that is otherwise generated and used by libcurl internally, your added one will be used instead. If you add a header with no contents as in 'Accept:' (no data on the right side of the colon), the internally used header will get disabled. Thus, using this option you can add new headers, replace internal headers and remove internal headers. To add a header with no contents, make the contents be two quotes: "". The headers included in the linked list must not be CRLF-terminated, because curl adds CRLF after each header item. Failure to comply with this will result in strange bugs because the server will most likely ignore part of the headers you specified. 
<p class="level1">The first line in a request (containing the method, usually a GET or POST) is not a header and cannot be replaced using this option. Only the lines following the request-line are headers. Adding this method line in this list of headers will only cause your request to send an invalid header. 
<p class="level1">Pass a NULL to this to reset back to no custom headers. 
<p class="level1">The most commonly replaced headers have "shortcuts" in the options <a class="emphasis" href="#CURLOPTCOOKIE">CURLOPT_COOKIE</a>, <a class="emphasis" href="#CURLOPTUSERAGENT">CURLOPT_USERAGENT</a> and <a class="emphasis" href="#CURLOPTREFERER">CURLOPT_REFERER</a>. 
<p class="level0"><a name="CURLOPTHTTP200ALIASES"></a><span class="nroffip">CURLOPT_HTTP200ALIASES</span> 
<p class="level1">Pass a pointer to a linked list of aliases to be treated as valid HTTP 200 responses.  Some servers respond with a custom header response line.  For example, IceCast servers respond with "ICY 200 OK".  By including this string in your list of aliases, the response will be treated as a valid HTTP header line such as "HTTP/1.0 200 OK". (Added in 7.10.3) 
<p class="level1">The linked list should be a fully valid list of struct curl_slist structs, and be properly filled in.  Use <a class="emphasis" href="./curl_slist_append.html">curl_slist_append(3)</a> to create the list and <a class="emphasis" href="./curl_slist_free_all.html">curl_slist_free_all(3)</a> to clean up an entire list. 
<p class="level1">The alias itself is not parsed for any version strings. Before libcurl 7.16.3, Libcurl used the value set by option <a class="emphasis" href="#CURLOPTHTTPVERSION">CURLOPT_HTTP_VERSION</a>, but starting with 7.16.3 the protocol is assumed to match HTTP 1.0 when an alias matched. 
<p class="level0"><a name="CURLOPTCOOKIE"></a><span class="nroffip">CURLOPT_COOKIE</span> 
<p class="level1">Pass a pointer to a zero terminated string as parameter. It will be used to set a cookie in the http request. The format of the string should be NAME=CONTENTS, where NAME is the cookie name and CONTENTS is what the cookie should contain. 
<p class="level1">If you need to set multiple cookies, you need to set them all using a single option and thus you need to concatenate them all in one single string. Set multiple cookies in one string like this: "name1=content1; name2=content2;" etc. 
<p class="level1">Using this option multiple times will only make the latest string override the previously ones. 
<p class="level0"><a name="CURLOPTCOOKIEFILE"></a><span class="nroffip">CURLOPT_COOKIEFILE</span> 
<p class="level1">Pass a pointer to a zero terminated string as parameter. It should contain the name of your file holding cookie data to read. The cookie data may be in Netscape / Mozilla cookie data format or just regular HTTP-style headers dumped to a file. 
<p class="level1">Given an empty or non-existing file or by passing the empty string (""), this option will enable cookies for this curl handle, making it understand and parse received cookies and then use matching cookies in future request. 
<p class="level1">If you use this option multiple times, you just add more files to read. Subsequent files will add more cookies. 
<p class="level0"><a name="CURLOPTCOOKIEJAR"></a><span class="nroffip">CURLOPT_COOKIEJAR</span> 
<p class="level1">Pass a file name as char *, zero terminated. This will make libcurl write all internally known cookies to the specified file when <a class="emphasis" href="./curl_easy_cleanup.html">curl_easy_cleanup(3)</a> is called. If no cookies are known, no file will be created. Specify "-" to instead have the cookies written to stdout. Using this option also enables cookies for this session, so if you for example follow a location it will make matching cookies get sent accordingly. 
<p class="level1">If the cookie jar file can't be created or written to (when the <a class="emphasis" href="./curl_easy_cleanup.html">curl_easy_cleanup(3)</a> is called), libcurl will not and cannot report an error for this. Using <a class="emphasis" href="#CURLOPTVERBOSE">CURLOPT_VERBOSE</a> or <a class="emphasis" href="#CURLOPTDEBUGFUNCTION">CURLOPT_DEBUGFUNCTION</a> will get a warning to display, but that is the only visible feedback you get about this possibly lethal situation. 
<p class="level0"><a name="CURLOPTCOOKIESESSION"></a><span class="nroffip">CURLOPT_COOKIESESSION</span> 
<p class="level1">Pass a long set to non-zero to mark this as a new cookie "session". It will force libcurl to ignore all cookies it is about to load that are "session cookies" from the previous session. By default, libcurl always stores and loads all cookies, independent if they are session cookies are not. Session cookies are cookies without expiry date and they are meant to be alive and existing for this "session" only. 
<p class="level0"><a name="CURLOPTCOOKIELIST"></a><span class="nroffip">CURLOPT_COOKIELIST</span> 
<p class="level1">Pass a char * to a cookie string. Cookie can be either in Netscape / Mozilla format or just regular HTTP-style header (Set-Cookie: ...) format. If cURL cookie engine was not enabled it will enable its cookie engine.  Passing a magic string "ALL" will erase all cookies known by cURL. (Added in 7.14.1) Passing the special string "SESS" will only erase all session cookies known by cURL. (Added in 7.15.4) 
<p class="level0"><a name="CURLOPTHTTPGET"></a><span class="nroffip">CURLOPT_HTTPGET</span> 
<p class="level1">Pass a long. If the long is non-zero, this forces the HTTP request to get back to GET. usable if a POST, HEAD, PUT or a custom request have been used previously using the same curl handle. 
<p class="level1">When setting <a class="emphasis" href="#CURLOPTHTTPGET">CURLOPT_HTTPGET</a> to a non-zero value, it will automatically set <a class="emphasis" href="#CURLOPTNOBODY">CURLOPT_NOBODY</a> to 0 (since 7.14.1). 
<p class="level0"><a name="CURLOPTHTTPVERSION"></a><span class="nroffip">CURLOPT_HTTP_VERSION</span> 
<p class="level1">Pass a long, set to one of the values described below. They force libcurl to use the specific HTTP versions. This is not sensible to do unless you have a good reason. 
<p class="level2">
<p class="level1"><a name="CURLHTTPVERSIONNONE"></a><span class="nroffip">CURL_HTTP_VERSION_NONE</span> 
<p class="level2">We don't care about what version the library uses. libcurl will use whatever it thinks fit. 
<p class="level1"><a name="CURLHTTPVERSION10"></a><span class="nroffip">CURL_HTTP_VERSION_1_0</span> 
<p class="level2">Enforce HTTP 1.0 requests. 
<p class="level1"><a name="CURLHTTPVERSION11"></a><span class="nroffip">CURL_HTTP_VERSION_1_1</span> 
<p class="level2">Enforce HTTP 1.1 requests. 
<p class="level1">
<p class="level0"><a name="CURLOPTIGNORECONTENTLENGTH"></a><span class="nroffip">CURLOPT_IGNORE_CONTENT_LENGTH</span> 
<p class="level1">Ignore the Content-Length header. This is useful for Apache 1.x (and similar servers) which will report incorrect content length for files over 2 gigabytes. If this option is used, curl will not be able to accurately report progress, and will simply stop the download when the server ends the connection. (added in 7.14.1) 
<p class="level0"><a name="CURLOPTHTTPCONTENTDECODING"></a><span class="nroffip">CURLOPT_HTTP_CONTENT_DECODING</span> 
<p class="level1">Pass a long to tell libcurl how to act on content decoding. If set to zero, content decoding will be disabled. If set to 1 it is enabled. Note however that libcurl has no default content decoding but requires you to use <a class="emphasis" href="#CURLOPTENCODING">CURLOPT_ENCODING</a> for that. (added in 7.16.2) 
<p class="level0"><a name="CURLOPTHTTPTRANSFERDECODING"></a><span class="nroffip">CURLOPT_HTTP_TRANSFER_DECODING</span> 
<p class="level1">Pass a long to tell libcurl how to act on transfer decoding. If set to zero, transfer decoding will be disabled, if set to 1 it is enabled (default). libcurl does chunked transfer decoding by default unless this option is set to zero. (added in 7.16.2) <a name="FTP"></a><h2 class="nroffsh">FTP OPTIONS</h2>
<p class="level0">
<p class="level0"><a name="CURLOPTFTPPORT"></a><span class="nroffip">CURLOPT_FTPPORT</span> 
<p class="level1">Pass a pointer to a zero terminated string as parameter. It will be used to get the IP address to use for the ftp PORT instruction. The PORT instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a host name, an network interface name (under Unix) or just a '-' letter to let the library use your systems default IP address. Default FTP operations are passive, and thus won't use PORT. 
<p class="level1">You disable PORT again and go back to using the passive version by setting this option to NULL. 
<p class="level0"><a name="CURLOPTQUOTE"></a><span class="nroffip">CURLOPT_QUOTE</span> 
<p class="level1">Pass a pointer to a linked list of FTP or SFTP commands to pass to the server prior to your ftp request. This will be done before any other commands are issued (even before the CWD command for FTP). The linked list should be a fully valid list of 'struct curl_slist' structs properly filled in with text strings. Use <a class="emphasis" href="./curl_slist_append.html">curl_slist_append(3)</a> to append strings (commands) to the list, and clear the entire list afterwards with <a class="emphasis" href="./curl_slist_free_all.html">curl_slist_free_all(3)</a>. Disable this operation again by setting a NULL to this option. 
<p class="level0"><a name="CURLOPTPOSTQUOTE"></a><span class="nroffip">CURLOPT_POSTQUOTE</span> 
<p class="level1">Pass a pointer to a linked list of FTP or SFTP commands to pass to the server after your ftp transfer request. The linked list should be a fully valid list of struct curl_slist structs properly filled in as described for <a class="emphasis" href="#CURLOPTQUOTE">CURLOPT_QUOTE</a>. Disable this operation again by setting a NULL to this option. 
<p class="level0"><a name="CURLOPTPREQUOTE"></a><span class="nroffip">CURLOPT_PREQUOTE</span> 
<p class="level1">Pass a pointer to a linked list of FTP commands to pass to the server after the transfer type is set. The linked list should be a fully valid list of struct curl_slist structs properly filled in as described for <a class="emphasis" href="#CURLOPTQUOTE">CURLOPT_QUOTE</a>. Disable this operation again by setting a NULL to this option. Before version 7.15.6, if you also set <a class="emphasis" href="#CURLOPTNOBODY">CURLOPT_NOBODY</a> non-zero, this option didn't work. 
<p class="level0"><a name="CURLOPTFTPLISTONLY"></a><span class="nroffip">CURLOPT_FTPLISTONLY</span> 
<p class="level1">A non-zero parameter tells the library to just list the names of an ftp directory, instead of doing a full directory listing that would include file sizes, dates etc. 
<p class="level1">This causes an FTP NLST command to be sent.  Beware that some FTP servers list only files in their response to NLST; they might not include subdirectories and symbolic links. 
<p class="level0"><a name="CURLOPTFTPAPPEND"></a><span class="nroffip">CURLOPT_FTPAPPEND</span> 
<p class="level1">A non-zero parameter tells the library to append to the remote file instead of overwrite it. This is only useful when uploading to an ftp site. 
<p class="level0"><a name="CURLOPTFTPUSEEPRT"></a><span class="nroffip">CURLOPT_FTP_USE_EPRT</span> 
<p class="level1">Pass a long. If the value is non-zero, it tells curl to use the EPRT (and LPRT) command when doing active FTP downloads (which is enabled by <a class="emphasis" href="#CURLOPTFTPPORT">CURLOPT_FTPPORT</a>). Using EPRT means that it will first attempt to use EPRT and then LPRT before using PORT, but if you pass FALSE (zero) to this option, it will not try using EPRT or LPRT, only plain PORT. (Added in 7.10.5) 
<p class="level1">If the server is an IPv6 host, this option will have no effect as of 7.12.3. 
<p class="level0"><a name="CURLOPTFTPUSEEPSV"></a><span class="nroffip">CURLOPT_FTP_USE_EPSV</span> 
<p class="level1">Pass a long. If the value is non-zero, it tells curl to use the EPSV command when doing passive FTP downloads (which it always does by default). Using EPSV means that it will first attempt to use EPSV before using PASV, but if you pass FALSE (zero) to this option, it will not try using EPSV, only plain PASV. 
<p class="level1">If the server is an IPv6 host, this option will have no effect as of 7.12.3. 
<p class="level0"><a name="CURLOPTFTPCREATEMISSINGDIRS"></a><span class="nroffip">CURLOPT_FTP_CREATE_MISSING_DIRS</span> 
<p class="level1">Pass a long. If the value is non-zero, curl will attempt to create any remote directory that it fails to CWD into. CWD is the command that changes working directory. (Added in 7.10.7) 
<p class="level1">This setting also applies to SFTP-connections. curl will attempt to create the remote directory if it can't obtain a handle to the target-location. The creation will fail if a file of the same name as the directory to create already exists or lack of permissions prevents creation. (Added in 7.16.3) 
<p class="level0"><a name="CURLOPTFTPRESPONSETIMEOUT"></a><span class="nroffip">CURLOPT_FTP_RESPONSE_TIMEOUT</span> 
<p class="level1">Pass a long.  Causes curl to set a timeout period (in seconds) on the amount of time that the server is allowed to take in order to generate a response message for a command before the session is considered hung.  While curl is waiting for a response, this value overrides <a class="emphasis" href="#CURLOPTTIMEOUT">CURLOPT_TIMEOUT</a>. It is recommended that if used in conjunction with <a class="emphasis" href="#CURLOPTTIMEOUT">CURLOPT_TIMEOUT</a>, you set <a class="emphasis" href="#CURLOPTFTPRES