Dentist System.c

//--- Header Files ----
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>  /**This library is only for unix users (Mac or Linux) for windows users this library would have to be
                     replaced with the time.h library to use the sleep() function**/

#include <termios.h> /**This library is only for unix users (Mac or Linux) for windows users this library would have to be
                     replaced with the conio.h library to use the getch() function**/
//---------------------

//--- Function Proto-types-----
void login();               //Login Function username: Admin password: P@$$w0rd (case sensitive)
/**int displaymenu();       //Display the menu
void menu();                //Calls the respective function based on the option selected in the menu displayed
void add();                 //Allows the user to add patients into a structure array
void search();              //ALlows the user to search for a patients based on patient number
void display(); **/         //Displays all patient detals
//---------------------------------------------------------------------------------------------------

//------------------------- MAIN FUNCTION ------------------------
int main()
{
    int choice;
    login();                //Calling the login function
    //choice=displaymenu();   //Calling the display menu function and storing the return valued the the variable "choice"
    //menu(choice);         //Calling the "choice" option function from the menu function
    //getch();              //Holds the information on the screen until a key is pressed
    return 0;
}
//--------------------------------------------------------------------------------------------------

//------------------- LOGIN FUNCTION -----------------------------
void login()
{
    int i;                                       //Variable Declaration
    char uid[25],pwd[25],s_uid[25]={"Admin"};    /**Created three variables one for user ID (uid[25]) and one user password
                                                 (pwd[25]). s_uid[25] is the varible holding the user ID the user is suppose to
                                                 enter to get in the system. Anything other that user ID (Admin) will be not
                                                 have access to the system**/

    char s_pwd[25]={"p@$$w0rd"},ch=' ';          /**Created a variable (s_pwd[25]) to hold the password the user is suppose to
                                                 enter to get access to the system. Anything other that user password (p@$$w0rd)
                                                 will be not have access to the system. **/
    puts("\n\n\n\n\n\t\t\t\t    WELCOME");
    puts("\n\t\t    CHAPELTON DENTISTRY REGISTRATION SYSTEM");
    puts("\n\t \t \t |-----------------------------|");
    puts("\t \t \t |             LOGIN           |");
    puts("\t \t \t |-----------------------------|");
    printf(" \t \t \t |Enter the User ID : ");
    scanf("%s",uid);
    getchar();
    printf(" \t \t \t |Enter the Password : ");
    i=0;
    while(1)     //Loops code forever
    {
        ch=getch();
        if(ch==10)           //10 is the ASCII value for the "Enter" key. Windows users would use the value 13 instead.
            break;           //Exit loop
        else if(ch==127)     //127 is the ASCII value for the "backspace" key. Windows users would use the value 8 instead.
        {       if(i!=0)     //This is for avoiding the input from being deleted
            {
                printf("\b");       //'\b' represents blackspace escape character
                printf(" ");
                printf("\b");       //'\b' represents blackspace escape character
                i--;                //Go back to the array position that had the character that was removed by backspace
                pwd[i]='\0';        //End of array
            }
            else
                continue;
        }
        else
        {
            putchar('*');         //Replaces each character type by a *
            pwd[i]=ch;            //Adds the character typed to the pwd array
            i++;                  //Move to the next postion in the array
        }
    }
    puts("\n \t \t \t |-----------------------------|");
    pwd[i]='\0';
    if((strcmp(uid,s_uid))==0 && (strcmp(pwd,s_pwd))==0) //checks if the user input is the same as what was set in the code (Admin, p@$$20rd)
    {
        printf("\t \t \t |\t USER AUTHENTICATED    |");
        puts("\n \t \t \t |-----------------------------|");
        sleep(1); //Pause the program for 1 second. Windows users would have to change this function to Sleep(1000) to get the same result
        system("clear"); //"clear" is for unix users. Windows users whould use "cls" instead of "clear"
    }
    else
    {
        printf("\t \a \t \t |UNABLE TO AUTHENTICATE USER, |\n \t \t \t | \t    Try again\t       |");
        puts("\n \t \t \t |-----------------------------|");
        sleep(2); //Pause the program for 2 second. Windows users would have to change this function to Sleep(2000) to get the same result
        system("clear"); //"clear" is for unix users. Windows users whould use "cls" instead of "clear"
        fflush(stdin);
        login(); //Recall the login function (Recursion)
    }
}
//-----------------------------------------------------------------------------------------


//------------------- GETCH FUNCTION -----------------------------
/**BECAUSE UNIX SYSTEMS DON'T SUPPORT THE CONIO.H LIBRARY THAT CONTAINS IT'S OWN BUILT IN GETCH() FUNCTION
WE HAVE TO MANUALLY BUILD A GETCH FUNCTION SUPPORTED BY THE TERMIOS.H LIBRARY. WINDOWS USERS CAN USE INCLUDE
THE CONIO.H AND REMOVE THIS FUNCTION**/

int getch(void)
{
    struct termios oldattr, newattr;
    int ch;
    tcgetattr( STDIN_FILENO, &oldattr );
    newattr = oldattr;
    newattr.c_lflag &= ~( ICANON | ECHO);//knock down keybuffer
    tcsetattr( STDIN_FILENO, TCSANOW, &newattr );
    system("stty -echo");//shell out to kill echo
    ch = getchar();
    system("stty echo");
    tcsetattr( STDIN_FILENO, TCSANOW, &oldattr );
    return ch;
}
//-----------------------------------------------------------------------------------------