I was given this short program on password and works perfectly. I understand all parts except the below statement.
Please help me to understand the place where I put a //PHP Code:if (num != 9)
{
num = 0;
while ((pass[num] = getch()) != 13) // [I]why 13?[/I]
{
putchar('*');
num++;
}
pass[num] = '\0';
}
else
goto Loop;
Last edited by sturm100; 05-30-2002 at 03:18 AM.
> goto Loop;
Blech!
> // why 13?
That's c++ commenting BTW.
Prelude posted a password masking code a little ways back, do a search for it.
The world is waiting. I must leave you now.
Actually
Who uses the search function anymore.Code:/* Program: Pwd.c Purpose: Demonstrates replacing characters with ****, in the event of hiding a password. */ #include <stdio.h> #include <conio.h> int main(void) { int ch; printf ( "Enter your password: " ); while ( ( ch = getch() ) != '\r' ) { putchar ( '*' ); } printf ( "\nThank you\n" ); return 0; }
> // why 13?
To expand, the password must be preset to 13 characters.
The above example simply waits untill the "return key" is pressed.
The world is waiting. I must leave you now.
I mean i understand the code but why a 13 and not 12 or 14 or 9? I tried putting a 9 and the system hang
> I mean i understand the code
So do I. It's poor.
The world is waiting. I must leave you now.
i have even enter more than 13 characters and still it wont prompt for wrong password till i press enter.
By the way, I like this code coz its able to allow the user to key in 3 tries before the program shutdown, and the password is mask by *
The code I posted masks input this way too.I like this code coz its able to allow the user to key in 3 tries before the program shutdown, and the password is mask by *
However, you code everything else.
Unlimited tries until they decide to stop.
Preferably, without goto, while using correct /* C comments. */
[EDIT]
BTW, if you want help for this question, post all code relevant to the password section of the program. Anything that would effect it.
[/EDIT]
The world is waiting. I must leave you now.
Actually I have no problem running the program, just that I have to explain why the statement is written this way.
13 is an ASCII carriage return, that's why your original loop was checking for it.
www.asciitable.com
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
ok heres the program, as i am a beginner, i wanted to learn why its written 13 and 9. and why when i replace the "char pass[9] to [8], the whole program goes to endless loop. if i am not wrong the [9] denotes the number of characters in the password but how come i can only put 8 char instead (if i add one more, the program will go to endless loop when i key in the correct password?
PHP Code:
void password(void)
{
char pass[9], password[9] = "pass1234"; /*password will be max at 8 characters*/
int num, repeat = 0;
Loop:
if (repeat > 2) /*if password enter incorrect 3 times, prompt and exit*/
{
clrscr();
mainpage();
gotoxy(30,30); printf("Check your password and try again.");
getch();
exit(1);
}
clrscr();
mainpage();
gotoxy(23,20);printf("Please Enter Password: ");
if (num != 9)
{
num = 0;
while ((pass[num] = getch()) != 13)
{
putchar('*');
num++;
}
pass[num] = '\0';
}
else
goto Loop;
if (strcmp(pass, password) == 0) /* password comparison
{
clrscr();
mainpage();
gotoxy(23,20);
printf("Access granted!");
getch();
menu();
}
else
{
clrscr();
mainpage();
gotoxy(23,22);
printf("Access denied!");
repeat++;
getch();
goto Loop;
}
}
It's 13 because of what I said in my last post.Originally posted by sturm100
i wanted to learn why its written 13 and 9.
Its 9 here
>password[9] = "pass1234";
because the length of the string is 8 characters, and you need 1 extra to hold the NULL terminator that denotes the end of the string.
When all else fails, read the instructions.
If you're posting code, use code tags: [code] /* insert code here */ [/code]
> goto Loop;
> Loop:
Loop.
The world is waiting. I must leave you now.
I see, thanks a lot
well carraige return means the cursor at the beginning right?
by the way, how do one know is a ascii code? from the code it looks like a number of char string to me....
how u see that so fast?
i trying to make sense of that part... really difficult to understand...
Thanks for the pointer
?????
i dun understand.....
> well carraige return means the cursor at the beginning right?
..of the next line, yes.
The world is waiting. I must leave you now.
