Socket server C linux problem write data receive

See more:

C

C#

sockets

hello:

I am trying to create a socket server that is working correctly for me.

I just have a problem. I try to write what I receive from the data in the socket in a file but it is not writing it to me.

The other extreme point sends me the data in ascii text through the socket. I see them in the console of the running service but it does not write it to the file that I want. My idea is also to make that file overwrite everything every 5 second I receive data.

But my main help that I need is to correct the problem to be able to write what comes to me in the file.

Here is an example of the code I'm working on:

<pre>#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <stdlib.h>

#define BUFS 1024
#define MAX_LENGTH 4096

int     Asock;  /* socket en listen on */

/* function prototypes */
void err_log(char []);
void do_server(int);
void cleanUp();

main(int argc, char *argv[])
{
    int     sock;
    int     hostport, len, pid;
    struct sockaddr_in  server, client;

    /* Linea de comando Valida */
    if(argc != 2) {
        fprintf(stderr,"Usage: sockserver <port no.>\n");
        exit(1);
    }

    /* get server port */
    hostport = atoi(argv[1]);

    /* Abre un TCP stream socket */
    if((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        err_log("ERROR: socket() failed");
        exit(1);
    }

    /* bind the server port */
    memset((char *) &server, 0, sizeof server);
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = htonl(INADDR_ANY);
    server.sin_port = htons(hostport);
    if(bind(sock, (struct sockaddr *) &server, sizeof server) < 0 ) {
        err_log("ERROR: bind() failed");
        exit(1);
    }
<pre> /* listen on the port for a connection request */
    listen(sock, 2);

    /* do a clean exit when user stops this program via  Break/Delete */
    signal(SIGINT, cleanUp);


    /* infinite loop */
    for( ; ; ) {
        fprintf(stderr, "Listening on port %d...\n", hostport);
        len = sizeof client;
        if((Asock = accept(sock, (struct sockaddr *)&client, &len)) < 0) {
            err_log("ERROR: accept() failed");
            exit(1);
        }

        /* fork a child processes for each connection */
        if((pid = fork()) < 0) {
            err_log("ERROR: fork() failed");
            exit(1);
        }

        if(pid == 0) {  /* child */
            close(sock);
            do_server(Asock);   /* read & write the data */
            exit(0);
        }
        else {          /* parent */
            close(Asock);
        }
    }
}


/*
 * Function: err_log() - error logging
 */
void err_log(char msg[])
{
    FILE    *fp;

    fp = fopen("./sockserver.log", "a+");
    fprintf(fp, "%s\n\n", msg);
    fclose(fp);
    fprintf(stderr, "\n%s\n\n", msg);
}


/*
 * Function: do_server() - write data to stdout
 */
void do_server(int fd)
{
    char buf[BUFS];
    int r;
    int read_bytes(int, char *, int);
<pre>    while((r = read_bytes(fd, buf, 1)) > 0)
        write(1, buf, r);

}


/*
 * Function: read_bytes() - read data into a buffer
 *
 * See UNIX Network Programming, 2nd Edition, Volume 1, pg. 77
 *     by W. Richard Stevens
 */
int read_bytes(int fd, char *buf, int bytes)
{
    int n,r;

    n = bytes;
    while (n > 0) {
        r = read(fd, buf, n);
        if(r > 0) {
            n = n - r;
            buf = buf + r;
        }
        else {
            if(r == 0)
                break;      /* end */
            else
                return(r);  /* error */
        }
    }
    return (bytes - n);
}

/*int write_line(char string[MAX_LENGTH])
{

    FILE *fp;


    fp = fopen("./vdn.log", "a+");
    fwrite(string, sizeof ( char ), strlen(string), fp);
    fclose(fp);
    return 0;
}
*/
int write_line(char string[MAX_LENGTH]){
    FILE *fp;

    char* array = strdup(string);
    char* filename="vdn.txt";
    char* dir=get_current_dir_name();

    char fullpath[MAX_LENGTH];

    strcat(fullpath, dir);
    strcat(fullpath, "/");
    strcat(fullpath, filename);
<pre>
    fp=fopen(fullpath, "a");

    if(fp==NULL)
    {
        return -1 ;
    }

    int i;

    for (i=0; i<strlen(string); i++)
    {
        fprintf(fp,"%c",*(array+i));
    }
    fclose(fp);

    bzero(fullpath, MAX_LENGTH);

    return 0;
}

/*
 * Function: cleanUp() - close the socket quickly
 */
void cleanUp()
{
    err_log("NOTICE: caught intr signal");
    shutdown(Asock, 2); /* clean & quick close */
    close(Asock);
    exit(0);
}

What I have tried:

hello:

I am trying to create a socket server that is working correctly for me.

I just have a problem. I try to write what I receive from the data in the socket in a file but it is not writing it to me.

The other extreme point sends me the data in ascii text through the socket. I see them in the console of the running service but it does not write it to the file that I want. My idea is also to make that file overwrite everything every 5 second I receive data.

But my main help that I need is to correct the problem to be able to write what comes to me in the file.

Here is an example of the code I'm working on