asked on

Fine tuning the password function

Here's a password function i have that does what it's supposed to.

Now to fine tune it I want to incorporate the backspace so that when a backspace character is detected n goes back to n-1 (i.e. previous character)

eg. if i enter "johns" then press backspace i want n to go back to 4 to overwrite the 's'.

/* Accepting Hidden Password */
void password(char buf[])
{
int n=0;

do
{
buf[n++]=getch();
if(buf[n-1]!='\r')
putch('*');
}
while(buf[n-1]!='\r');
buf[n-1]='\0';
}

brettmjohnson

char * getpassword(void)
{
static char passwd[255];
int i;

printf("password: ");

for (i = 0; i < 254;) {
int ch = getch();
/* CR or NL terminates input */
if ((ch == '\n') || (ch == '\r')) {
break;
}
/* Backspace or Delete backs up */
if ((ch == '\b') || (ch == '\377')) {
if (i > 0) i--;
else putch('\a');
} else {
passwd[i++] = (char)ch;
putch('*');
}
}
passwd[i] = '\0';
return 0;
}

mkandre

ASKER

Thanks, but you should have returned passwd instead of 0.

/* Backspace or Delete backs up */
if ((ch == '\b') || (ch == '\377')) {
if (i > 0) i--;
else putch('\a');
} else {
passwd[i++] = (char)ch;
putch('*');
}
}
passwd[i] = '\0';
return 0; <======right here
}

Secondly at the point

>if(i > 0) i--;
> else putch('\a');

i want to print a backspace character so that it removes the last * printed

something like

if(i>0) {i--; putch('\b');}
else putch('\a');

the problem with '\b' is that it only moves the cursor back one space, not delete the last printed character.

suggestion...

ASKER CERTIFIED SOLUTION

brettmjohnson

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mkandre

ASKER

Thank you! This was a relatively easy question, I just wanted to give some points away.

You've earned it, so 10 bonus points.

mkandre.