void pw_tofile(char * login, char * new_password){
    FILE *fp;
    FILE *new_file;

    char line[MAX_PASSWORD];

    if ((fp = fopen("client.aut.txt","r")) == NULL){
        printf("File missing\n");
        exit(0);
    }
    new_file = fopen("new_aut.txt","w");

    while(!feof(fp)){
        //reads a login so MAX_LOGIN
        fgets(line,MAX_LOGIN,fp);
        printf("user: %s",line);
        fputs(line,new_file);
        if ((strncmp(login,line,strlen(login))) == 0){
            printf("Encontered client\n");
            //skips old password
            fgets(line,MAX_PASSWORD,fp);
            printf("password: %s",line);
            //writes new password to new file
            fputs(new_password,new_file);
            fputs("\n",new_file);
        }
        else{
            //reads password and writes to new file
            fgets(line,MAX_PASSWORD,fp);
            printf("password: %s",line);
            fputs(line,new_file);
        }
        //reads aut and writes to new file
        fgets(line,MAX_LOGIN,fp);
        printf("aut: %s",line);
        fputs(line,new_file);
    }

    /*if((rename("new_aut.txt","client.aut.txt")) == -1){
        printf("Error renaming new file");
    }*/

    fclose(fp);
    fclose(new_file);

}