cgi

在web端用F12也可以查看network：GET post的情况。cgi代码并不长，区分以下普通和文件的上传：x-www-form-urlencoded与multipart/form-data区别。

cgiGetenv(&cgiServerSoftware, (char*)"SERVER_SOFTWARE");//lighttpd/1.4.35 ---明显取得web服务器以及版本

cgiGetenv(&cgiServerName, (char*)"SERVER_NAME");//192.168.59.254 ---域名

cgiGetenv(&cgiGatewayInterface, (char*)"GATEWAY_INTERFACE");//CGI/1.1 ---CGI通用网关结构

cgiGetenv(&cgiServerProtocol, (char*)"SERVER_PROTOCOL");//HTTP/1.1 ---服务器协议版本

cgiGetenv(&cgiServerPort, (char*)"SERVER_PORT");//80 ---端口

cgiGetenv(&cgiRequestMethod, (char*)"REQUEST_METHOD");//GET ---web请求方法。GET,SET我也不是很熟

cgiGetenv(&cgiPathInfo, (char*)"PATH_INFO");//NULL

cgiGetenv(&cgiPathTranslated, (char*)"PATH_TRANSLATED");//NULL

cgiGetenv(&cgiScriptName, (char*)"SCRIPT_NAME");///cgi-bin/login.cgi ----调用的脚本名字

cgiGetenv(&cgiQueryString, (char*)"QUERY_STRING");//NULL ----请求的数据，如action=login&username=Administrator&password=WiDi

cgiGetenv(&cgiRemoteHost, (char*)"REMOTE_HOST");//192.168.59.40 ----远端主机名

cgiGetenv(&cgiRemoteAddr, (char*)"REMOTE_ADDR");//NULL

cgiGetenv(&cgiAuthType, (char*)"AUTH_TYPE");//NULL

cgiGetenv(&cgiRemoteUser, (char*)"REMOTE_USER");//NULL

cgiGetenv(&cgiRemoteIdent, (char*)"REMOTE_IDENT");//NULL

............................................................

cgiGetenv(&cgiContentLengthString, (char*)"CONTENT_LENGTH");//0 ---访问时内容长度

cgiContentLength = atoi(cgiContentLengthString);

cgiGetenv(&cgiAccept, (char*)"HTTP_ACCEPT");//text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 ---应该是可以接收的格式。html,xhtml,xml（猜的）。

cgiGetenv(&cgiUserAgent, (char*)"HTTP_USER_AGENT");//Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:39.0) Gecko/20100101 Firefox/39.0 ---访问代理Firefox

cgiGetenv(&cgiReferrer, (char*)"HTTP_REFERER");//http://192.168.59.254/index.html ---web访问的地址

cgiGetenv(&cgiCookie, (char*)"HTTP_COOKIE");//lang=English; SESSIONID=E85F333900B0B4586A0E25A1CC9B0A21 ---与web端会话ID

对应输出结果：

SERVER_SOFTWARE==lighttpd/1.4.35

SERVER_NAME==192.168.59.254

GATEWAY_INTERFACE==CGI/1.1

SERVER_PROTOCOL==HTTP/1.1

SERVER_PORT==80

REQUEST_METHOD==GET

SCRIPT_NAME==/cgi-bin/login.cgi

REMOTE_ADDR==192.168.59.40

CONTENT_LENGTH==0

HTTP_ACCEPT==text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

HTTP_USER_AGENT==Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:39.0) Gecko/20100101 Firefox/39.0

HTTP_REFERER==http://192.168.59.254/index.html

HTTP_COOKIE==lang=English; SESSIONID=E85F333900B0B4586A0E25A1CC9B0A21

Web session invalid

如果REQUEST_METHOD==POST说明是设置命令如：SET http://localhost/Jack/cgi-bin/out.cgi?theText=it%27s+me
其中theText是html/javascript中定义的输入接口名称。it%27s+me为输入的内容。

对应函数：cgiParseFormInput

typedef struct cgiFormEntryStruct {

char *attr;//属性名，html中定义的，保存在这里POST上传

/* value is populated for regular form fields only.

For file uploads, it points to an empty string, and file

upload data should be read from the file tfileName. */

char *value;//对应的数据

/* When fileName is not an empty string, tfileName is not null,

and 'value' points to an empty string. */

/* Valid for both files and regular fields; does not include

terminating null of regular fields. */

int valueLength;//数据长度

char *fileName;

char *contentType;

/* Temporary file name for working storage of file uploads. */

char *tfileName;

struct cgiFormEntryStruct *next;//下一个组上传属性。表头cgiFormEntryFirst

} cgiFormEntry;

cgiStrEqNc判断字符串相等。

cgiParsePostFormInput从cgin读取数据并解析POST到表头cgiFormEntryFirst

cgiParseGetFormInput从cgiQueryString解析数据到cgiFormEntryFirst

cgiCookies用来提取cgiCookie中如：lang和SESSIONID的名字--不是value

get_cgi_session_id这是用户层代码了，用来查看cgiCookie中是否有SESSIONID信息。