使用 C 编写的过滤器应用程序 (SimpleFilter.c)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcgi_stdio.h>

		void main(void) {
			size_t PageSize = 1024 * 3;
    		char *page;
    		FCGX_Stream *in, *out, *err;
    		FCGX_ParamArray envp;

		 	int count=0;
    		page = (char *)malloc(PageSize);

		 	if (page == NULL) {

				printf("Content-type: text/x-server-parsed-html\r\n");
				printf("<title>malloc failure</title>");
				printf("<h1>Cannot allocate memory to run filter. exiting</h1>");
				printf("\r\n\r\n");
				exit(2);
			}

			while(FCGI_Accept() >= 0) {

         	char *tmp;
         	char *execcgi;      
         	char *dataLenStr = NULL;
         	int numchars = 0;
         	int stdinDataSize = 0;
         	int filterDataLen = 0;
         	int dataToBeRead = 0;
         	int x = 0;
         	int loopCount = 0;   
				

			  	count++;
         	dataLenStr = getenv("FCGI_DATA_LENGTH");
        
         	if(dataLenStr)
             	filterDataLen = atoi(dataLenStr);
   
				/* clear out stdin */
         	while (EOF != getc(stdin)) {
             	stdinDataSize++;
         	}

				dataToBeRead = filterDataLen;
        	FCGI_StartFilterData();
        	tmp = page; /** just in case fread or fwrite moves our pointer **/


				//start responding
				printf("Content-type: text/plain\r\n");
				printf("\r\n"); /** send a new line at the beginning **/
				printf("<title>SIMPLE FILTER</title>");
				printf(<h1>This page was Filtered by SimpleFilter FastCGI filter</h1>");
				printf("file size=%d<br>", filterDatalen);
				printf("stdin size=%d<br>, stdinDataSize);


				while(dataToBeRead > 0 ) {
           		x = 0;
           		page = tmp;
            
           		if(dataToBeRead > PageSize)
             		 x = PageSize;
           		else
              		 x = dataToBeRead;
					numchars = fread((void *)(page), 1, x, stdin);
				
					if( numchars == 0 )
						continue; 
					/** at this point your data is in page pointer, so do 
					whatever you want 
               with it before sending it back to the server.
					In this example, no data is manipulated. Only the count of number of 
               times the filter data is read and the total bytes read 
					at the end of every 
               loop is printed. **/	

					dataToBeRead -= numchars;
					loopCount++;
					printf("loop count = %d ... so far read %d bytes <br>", loopCount, 
					(filterDatalen - dataToBeRead));
				}
				printf("\r\n\r\n"); /** send a new line at the end of transfer **/

				fflush(stdout);

				page = tmp; /** restore page pointer **/
				memset(page,NULL,numchars);
		}

		free(page);
}

以上示例的 obj.conf 设置示例。

如果该 FastCGI 应用程序是在运行 Web Server 的计算机上运行，则

<Object name=<"filter.fcgi">
						Service fn="filter-fastcgi" app-path="/fastcgi/apps/filter/SimpleFilter.exe" 
             bind-path="localhost:3434" app-env="LD_LIBRARY_PATH=/fastcgi/fcgi-2.4/libfcgi/.libs"
</Object>

如果该应用程序正在远程计算机上运行，则必须在 obj.conf 文件中包含以下代码行：

<Object name="filter.fcgi">
			Service fn="filter-fastcgi" bind-path="<remote-host>:<remote-port>"
</Object>

如果要过滤 Web Server 实例根目录下的 fcgi 目录中大小为 "26868" 字节的 "FilterThisFile" 文件，则对 "http://localhost/fcgi/filter/FilterThisFile" 的请求将生成以下输出：

This page was Filtered by SimpleFilter FastCGI filter