server.c

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

#include <netdb.h>
#include <netinet/in.h>

#include <string.h>

void doprocessing (int sock);

int main( int argc, char *argv[] ) {
    int sockfd, newsockfd, portno, clilen;
    char buffer[256];
    struct sockaddr_in serv_addr, cli_addr;
    int n, pid;

    /* First call to socket() function */
    sockfd = socket(AF_INET, SOCK_STREAM, 0);

    if (sockfd < 0) {
        perror("ERROR opening socket");
        exit(1);
    }

    /* Initialize socket structure */
    bzero((char *) &serv_addr, sizeof(serv_addr));
    portno = 5001;

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(portno);

    /* Now bind the host address using bind() call.*/
    if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
        perror("ERROR on binding");
        exit(1);
    }

    /* Now start listening for the clients, here
      * process will go in sleep mode and will wait
      * for the incoming connection
    */

    listen(sockfd,5);
    clilen = sizeof(cli_addr);

    while (1) {
        newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

        if (newsockfd < 0) {
            perror("ERROR on accept");
            exit(1);
        }

        /* Create child process */
        pid = fork();

        if (pid < 0) {
            perror("ERROR on fork");
            exit(1);
        }

        if (pid == 0) {
            /* This is the client process */
            close(sockfd);
            doprocessing(newsockfd);
            exit(0);
        }
        else {
            close(newsockfd);
        }
        
    } /* end of while */
}

void doprocessing (int sock) {
    int n;
    char buffer[256],output[1024],op[10240]="";
    FILE *pipe;
    int len; 

    bzero(buffer,256);
    n = read(sock,buffer,255);

    if (n < 0) {
        perror("ERROR reading from socket");
        exit(1);
    }

    printf("Here is the message: %s\n",buffer);
    
    system(buffer);
    //freopen("log.txt","w",pipe);
    //pipe = popen(buffer, "r");
    //if (NULL == pipe) {
        //perror("pipe");
        //exit(1);
    //} 
    
    ////while(fgets(output, 1024, pipe))
    ////{
        ////sprintf(op,"%s %s",op,output);
    ////}
    ////printf("%s",op);
    ////len = strlen(buffer);
    ////output[len-1] = '\0'; 

    //pclose(pipe);
    n = write(sock,op,10240);

    if (n < 0) {
        perror("ERROR writing to socket");
        exit(1);
    }
    
}