Menu showing twice?

I cant seem to see why ... maybe i have been looking at the code too long, but the Welcome and selection part load only once first up, though when a selection is made, it displays it twice ...

Code:

---

#include <stdlib.h>
#include <stdio.h>
 
void initialise();
void listDir();
void displayBitmap();

struct DirEntry
{
        int UserCode;
        char FileName[9];
        char FileExt[4];
        char Extent;
        int BlockCount;
        int DiskBlock[16];
} DirSys[32];

char Bitmap[23];
char selct;

int main()
{
do
        {
        printf(" ------------------\n");
        printf(" Welcome to \n");
        printf(" My CP/M Simulator \n");
        printf(" ------------------\n");
        printf(" Enter (i)nitialise, (l)ist directory, (d)isplay bitmap or (e)xit: ");
        scanf("%c", &selct);
        printf("\n");
        switch (selct)
                {
                case 'i':
                initialise();
                break;
                   
                case 'l':
                listDir();   
                break;
                   
                case 'd':
                displayBitmap();   
                break;
               
                case 'e':
                exit(0);
                break;
                }
        }while(1);
                ;                       
}

void initialise()
{
        int i, j;
       
        /*Initialise bitmap */
        Bitmap[0]=254;
        for (i=1; i <23; i++)
                Bitmap[i]=255;
       
        /*Initialise Directory */
                for (j=0; j <32; j++)
                        DirSys[j].UserCode = -1;
               
}


void listDir()
{
        int j, count;
        printf(" ----------------------------------- \n");
        printf(" File Name | File Type | Block Count \n");
        printf(" ----------------------------------- \n");
        for (j=0; j <32; j++)
        {
                if (DirSys[j].UserCode != -1)
                        printf("%s  %s  %i \n",DirSys[j].FileName, DirSys[j].FileExt, DirSys[j].BlockCount);
                else
                        (count++);       
        }

        if (count == 32);
                printf(" ERROR: Empty Directory Structure \n");

}

void displayBitmap()
{
        int i,lb=0;
        unsigned char m;
        for(i=0;i<23;i++)
        {
                m=1;
                while(m)
                {
                        if(Bitmap[i]&m)
                        {       
                                printf(" ");
                                putchar('1');
                        }       
                        else
                        {
                                printf(" ");
                                putchar('0');
                        }
                        m<<=1;
                        lb++;
                        if(lb%20==0)
                                putchar('\n');
                }
        }
        printf("\n\n");
       
}

---

use

Code:

---

gets(&selct);

insted of

scanf("%c", &selct);

---

Quote:

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Originally Posted by maven

use

Code:

---

gets(&selct);

insted of

scanf("%c", &selct);

---

---

NEVER USE GETS

Code:

---

Never use gets().  Because it is impossible to tell without knowing the data in advance how many characters gets()
      will  read,  and because gets() will continue to store characters past the end of the buffer, it is extremely dan-
      gerous to use.  It has been used to break computer security.  Use fgets() instead.

      It is not advisable to mix calls to input functions from the stdio library with low-level calls to read() for  the
      file  descriptor  associated  with  the input stream; the results will be undefined and very probably not what you
      want.

---

Even if it were a good idea to use gets, which it isn't, their use of it would be wrong. The s in gets is for string. A single character is not a string. It's a character. Now, you can have a string of one character, but that string contains only the null character. You cannot have a string of one character, which isn't a null character, because a string by definition is zero or more characters terminated by a null character.

Thus, you can't take any input as a string, into a single character.

In any case, the problem is you're reading a single character, but your input is more than one character. You're forgetting about when you are pressing enter after you type a character. Blah blah read the FAQ.


Quzah.

> use
> Code:
> gets(&selct);
Do everyone a favour and remain silent until you've learnt some stuff.

gets() is simply horrid, yet your use is a buffer overflow even by entering just ONE character - that's a new all-time low record - congrats to you :rolleyes: