项目附 - 云盘项目-分析echo.c

分析FastCGI源码目录下example中echo.c代码：

 /*
  * echo.c --
  *
  *    Produce a page containing all FastCGI inputs
  *
  *
  * Copyright (c) 1996 Open Market, Inc.
  *
  * See the file "LICENSE.TERMS" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
  */
 #ifndef lint
 static const char rcsid[] = "$Id: echo.c,v 1.5 1999/07/28 00:29:37 roberts Exp $";
 #endif /* not lint */

 #include "fcgi_config.h"

 #include <stdlib.h>

 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif

 #ifdef _WIN32
 #include <process.h>
 #else
 extern char **environ;
 #endif

 #include "fcgi_stdio.h"

 //输出环境变量
 static void PrintEnv(char *label, char **envp)
 {
     printf("%s:<br>\n<pre>\n", label);
     for ( ; *envp != NULL; envp++) {
         printf("%s\n", *envp);
     }
     printf("</pre><p>\n");
 }

 int main ()
 {
     //environ 是指向环境变量 字符串数组（全局指针）
     //保存初始状态下的环境变量执政
     char **initialEnv = environ;
     int count = ;    //计数

     //阻塞点，有请求来 FCGI_Accept 就返回
     while (FCGI_Accept() >= ) {
         //获取 CONTENT_LENGTH 环境变量的值
         char *contentLength = getenv("CONTENT_LENGTH");
         int len;

     printf("Content-type: text/html\r\n"
         "\r\n"
         "<title>FastCGI echo</title>"
         "<h1>FastCGI echo</h1>\n"
             "Request number %d,  Process ID: %d<p>\n", ++count, getpid());

         if (contentLength != NULL) {
             //string 转 long
             len = strtol(contentLength, NULL, );
         }
         else {
             len = ;
         }

         if (len <= ) {
         printf("No data from standard input.<p>\n");
         }
         else {
             int i, ch;

         printf("Standard input:<br>\n<pre>\n");
             for (i = ; i < len; i++) {
                 if ((ch = getchar()) < ) {
                     printf("Error: Not enough bytes received on standard input<p>\n");
                     break;
         }
                 putchar(ch);
             }
             printf("\n</pre><p>\n");
         }

         //打印环境变量
         PrintEnv("Request environment", environ);
         PrintEnv("Initial environment", initialEnv);
     } /* while */

     return ;
 }

访问web服务器后的页面显示信息：

http://192.168.1.45/login?user=citrus&passwd=123456

http请求头的 key 和最后拿到的环境变量的 key 对应关系保存在 nginx fastcgi.conf 文件里面。

FastCGI echo
Request number 1, Process ID: 58012
No data from standard input.

Request environment:

FCGI_ROLE=RESPONDER
SCRIPT_FILENAME=/usr/local/nginx/html/login
QUERY_STRING=user=citrus&passwd=123456
REQUEST_METHOD=GET
CONTENT_TYPE=
CONTENT_LENGTH=
SCRIPT_NAME=/login
REQUEST_URI=/login?user=citrus&passwd=123456
DOCUMENT_URI=/login
DOCUMENT_ROOT=/usr/local/nginx/html
SERVER_PROTOCOL=HTTP/1.1
REQUEST_SCHEME=http
GATEWAY_INTERFACE=CGI/1.1
SERVER_SOFTWARE=nginx/1.13.10
REMOTE_ADDR=192.168.1.119
REMOTE_PORT=60974
SERVER_ADDR=192.168.1.45
SERVER_PORT=80
SERVER_NAME=localhost
REDIRECT_STATUS=200
HTTP_ACCEPT=text/html, application/xhtml+xml, image/jxr, */*
HTTP_ACCEPT_LANGUAGE=zh-CN
HTTP_ACCEPT_ENCODING=gzip, deflate
HTTP_HOST=192.168.1.45
HTTP_CONNECTION=Keep-Alive
HTTP_USER_AGENT=Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko Core/1.70.3741.400 QQBrowser/10.5.3863.400

Initial environment:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX省略