#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

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

#define STDOUT_FILENO 1
#define BAUDRATE B9600
#define MODEMDEVICE "/dev/ttyS0"


int main(void) 
{

        const char *str="W\r\n";
        char buf[64];
        int pos=0;
        int n, i, d ;
        char buff[20];
        FILE *fp1, *fp2;   
        
        fp1 = open("/dev/ttyS0", O_RDWR);
        if (d < 0) 
        {
            perror("Couldn't open");
        }

        system("stty -F /dev/ttyS0 1:0:80000dad:0:3:1c:7f:15:4:5:1:0:11:13:1a:0:12:f:17:16:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0");

        fp2 = fopen("/var/www/testfile.txt", "w+");

        fprintf(fp1, "%s","W\r");
        fread(buff,7,1, fp1);
        printf("buffer elements\n");
        for(i= 0; i < strlen(buff) + 1;i++)
            printf("%c", buff[i]);
         printf("You entered the string %s\n",buff);
        rewind(fp2);
        fwrite(buff, 1, 7,fp2 );

}