Question

我建立了一个C localhost webServer，它能够显示带有文本框和运行/提交按钮的基本html页面。当我这样做并输入诸如ls之类的基本命令时，它将带我进入localhost:3838/run?command=ls。我想知道的是，是否有可能从此文本框中获取ls的命令，以便能够解析该输入，然后将其发送到类似execvp的地方，然后再发送execvp的输出返回到webservers html页面，以在服务器上显示该运行命令的输出。如果可以，怎么办？

WebServer.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <signal.h>

#define PORT "3838" //port being connected to 
#define MAXLEN 800
#define BACKLOG 10 //number of pending connections to be held in queue

//format of html page 

char header []= 
"HTTP/1.1 200 Ok\r\n"
"Content-Type: text/html; charset=UTF-8\r\n\r\n"
"<!DOCTYPE html>\r\n"
"<html>\n"
"<head>\n"
"<title>Web-Based Remote Command Server</title>\r\n"
"</head>\n"
"<body>\n\n"
"<form action= \"/run\" method= \"get\"> \n"
"Command: <input type=\"text\" size=\"100\" name=\"command\">\n"
"<input type=\"submit\" value=\"Run\">\n"
"</form>"
"<p>Command that was run:</p>\n"
"<pre>Your server will include the command that was just run here.</pre>\n\n"
"<p>Standard Output:</p>\n""<pre>Your server will include the stdout results here.</pre>\n\n"
"<p>Standard Error:</p>\n"
"<pre>Your server will include the stderr results here.</pre>\n\n"
"</body>\n""</html>";

char *buff = header; 

void sigchld_handler(int s)
{
    (void)s; // quiet unused variable warning

    // waitpid() might overwrite errno, so we save and restore it:
    int saved_errno = errno;

    while(waitpid(-1, NULL, WNOHANG) > 0);

    errno = saved_errno;
}


void *get_in_addr(struct sockaddr *sa)
{
    if (sa->sa_family == AF_INET) {
        return &(((struct sockaddr_in*)sa)->sin_addr);
    }

    return &(((struct sockaddr_in6*)sa)->sin6_addr);
}


int main (void){
    int sockfd;
    int new_fd; 
    struct addrinfo hints;
    struct addrinfo *serverinfo; 
    struct addrinfo *p;
    struct sockaddr_storage client_addr;
    socklen_t addrsize;
    struct sigaction sa;
    int yes = 1;
    char s[INET6_ADDRSTRLEN];
    int status;

    memset(&hints, 0, sizeof hints); //makes struct empty 
    hints.ai_family = AF_UNSPEC; //IPv4 or v6 
    hints.ai_socktype = SOCK_STREAM; //TCP type need 
    hints.ai_flags = AI_PASSIVE; //Fill in IP for us 


    //if can't get address info print error 
    if((status = getaddrinfo(NULL, PORT, &hints, &serverinfo)) != 0){
        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
        return 1;
    }


    for(p = serverinfo; p != NULL; p = p->ai_next){
        if((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1){
            perror("server: socket");
            continue;
        }

        if(setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1){
            perror("setsockopt");
            exit(1);
        }

        if(bind(sockfd, p->ai_addr, p->ai_addrlen) == -1){
            close(sockfd);
            perror("server: bind");
            continue;
        }

        break;
    }

    freeaddrinfo(serverinfo);

    if(p == NULL){
        fprintf(stderr, "server: failed to bind\n");
        exit(1);
    }

    if(listen(sockfd, BACKLOG) == -1){
        perror("listen");
        exit(1);
    }

    sa.sa_handler = sigchld_handler; // reap all dead processes
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = SA_RESTART;
    if (sigaction(SIGCHLD, &sa, NULL) == -1) {
        perror("sigaction");
        exit(1);
    }

    printf("server: waiting for connections....\n");

    while(1){
        addrsize = sizeof client_addr;
        new_fd = accept(sockfd, (struct sockaddr *)&client_addr, &addrsize);
        if(new_fd == -1){
            perror("Did not accept");
            continue;
        }

        inet_ntop(client_addr.ss_family, get_in_addr((struct sockaddr *)&client_addr), s, sizeof s);
        printf("server: got connection from %s\n", s);

        if(!fork()){
            close(sockfd);
            int bufsize = 1024;
            char *buffer = malloc(bufsize);
            //recv(new_fd, buffer, bufsize, 0);
            //write(new_fd, "HTTP/1.1 200 OK\n", 16);
            //write(new_fd, "Content-length: 46\n", 19);
            //write(new_fd, "Content-type: text/html\n\n", 25);
            //write(new_fd, "<html><head>\n<head>\n<title>The CAvengers Web Page</title>\n</head>\n</html>", 46);

            if(send(new_fd, header, MAXLEN, 0) == -1)
                perror("send");
            close(new_fd);
            exit(0);
        }
        close(new_fd);
    }

    return 0;


}

C WebServer如何获取用户输入并能够解析

0 个答案: