Thread: Help with C code

I have the following code:

Code:

#include <stdio.h>
#include <curses.h>

void main(void)
{
 char username[15],ch;
 int i=0;
 printf("\nUsername:");

 while(1)
{
    ch = getch();
    if (ch == 10)
    {
    break;
    }
    else if (ch == 8 || ch == 127)
    {
     printf("\b\b");
    }
    else
    {
     username[i]=ch;
     i=i+1;
    };
}
 printf("\nWelcome %s.\n",username);
}

If I compile this and run it with
gcc mybbs.c -o mybbs -lncurses

I get a segmentation fault and I isolated it to the line username[i]=ch;
but I don't understand why. Also, the goal of the program is when a user presses the backspace key (code 8 and 127) on the keyboard in syncterm (a terminal program) I want it to simply erase the ^H thats displayed on the screen and send two backspaces with \b\b, can someone help please?

I've added the check, it no longer does a segmentation fault but also doesn't print the username with the printf statement. Is this because I'm using curses.h?

Code:

#include <stdio.h>
#include <curses.h>

void main(void)
{
 char username[15],ch;
 int i=0;
 printf("\nUsername:");

 while(1)
{
    ch = getch();
    if (ch == 10)
    {
    break;
    }
    else if (ch == 8 || ch == 127)
    {
     printf("\b\b");
    }
    else
    {
     if (i <= 15 )
     {
     username[i]=ch;
     i=i+1;
     };
    };
}
 printf("\nWelcome %s.\n",username);
}

It is still wrong though, read my post again. Which values are valid indices for you array?

Also, what problem are you trying to solve? For example, why are you using getch to read your input? Why are you checking for ASCII value 8 and 127? Why is ch still a char?

Code:

#include <stdio.h>

int main(void)
{
 char username[16],ch;
 int i=0;
 printf("\nUsername:");

 while(1)
{
    ch = getchar();
    if (ch == 10)
    {
    break;
    }
    else if (ch == 8 || ch == 127)
    {
     printf("\b\b");
     i--;
    }
    else
    {
     if (i <= 14 )
     {
     username[i]=ch;
     i=i+1;
     };
    };
}
 username[i+1]='\0';
 printf("\nWelcome %s.\n",username);
}

I made some changes based on your inputs, the goal is for this program to recognize the backspace keypress in syncterm and actually erase the last key instead of printing ^H on the screen. It is currently not working, it shows ^H on the screen.

My suggestion then is to configure your terminal correctly instead.

Local console is fine, its via syncterm the backspace key is not being intercepted and replaced by backspace.

Originally Posted by cnnx

Local console is fine, its via syncterm the backspace key is not being intercepted and replaced by backspace.

Yes, so again, fix your console so that it works with syncterm or switch software to something that works out of the box.

This is a configuration issue. I don't even understand how you think the program you are writing are going to help with the real issue you have?