Encryption program inside...

Hello,

I know this is a bad program and I have thrown in many bugs related to type conversion. I am getting a warning also. Can you help me correct it ?

Code:

---

#include<stdio.h>
#include<conio.h>
int main()
{
    char ch[256];
    int cha[256];
    int count;
    printf("Enter a sentence:");
    fgets(ch,256,stdin);
    printf("\n%s",ch);
    for(count=0;ch[count]!='\0';count++)
    {
                                        cha[count]=((int)ch[count]+2);     
    }
    cha[count]=0;
    printf("\n After Encryption:  ");
        /*    for(count=0;cha[count]!=0;count++)
    {
                                      printf("%c",cha[count]);
    }*/
   
    puts((char)cha); /* [Warning] cast from pointer to integer of different size */
    getch();
    return 0;
}

---

Thank you.

What is this program supposed to do?

Print it the same way that you did the original.
It seems to be a string ending in a nul.

Quote:

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Originally Posted by laserlight

What is this program supposed to do?

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Sorry.:p

It is supposed to take input string and then make it a jumbled secret code. It should add 2 to the ASCII value of each character.

Like A(=97) becomes B (=98).

Okay, so I'm guessing that the reason that you dont want to just do a printf() like earlier in the code is that you want to display the ASCII values of the "encrypted" characters?

Quote:

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Originally Posted by Salem

Print it the same way that you did the original.
It seems to be a string ending in a nul.

---

Yes, it is printing a special character (A circle with an arrow pointing downwards) after the encrypted string. But it was doing the same with printf so i commented it out and used puts, thought it would be better to use puts.

Quote:

---

you want to display the ASCII values of the "encrypted" characters?

---

No I want to display the characters, not their ASCII value.

If I input ABC it should give CDE.

But it is giving a special character (A circle with an arrow pointing downwards) after the E.

Ah, that is much clearer now.

Basically, you only need one string. You do not need an array of ints. Then you can just write:

Code:

---

for (count = 0; cha[count] != '\0' && cha[count] != '\n'; count++)
{
    cha[count] += 2;
}
cha[count] = '\0';
printf("\nAfter Encryption: %s", cha);

---

The catch is that if your string contains the characters '}' or '~', you will end up with unprintable characters.

> But it is giving a special character (A circle with an arrow pointing downwards) after the D.
That would be your encrypted version of the \n at the end of the line (as returned by fgets)

Edit:
Beaten.

Yes its working now. Thanks!

Quote:

---

Originally Posted by laserlight

Ah, that is much clearer now.

Basically, you only need one string. You do not need an array of ints. Then you can just write:

Code:

---

for (count = 0; cha[count] != '\0' && cha[count] != '\n'; count++)
{
    cha[count] += 2;
}
cha[count] = '\0';
printf("\nAfter Encryption: %s", cha);

---

The catch is that if your string contains the characters '}' or '~', you will end up with unprintable characters.

---

I think you were supposed to use ch[] not cha[]. And you can fix the problem of non-printable characters by putting an if statement:

Code:

---

for (count =0; ch[count] != '\0' && ch[count] != '\n'; count++)
{
    if (ch[count] >= sizeof(char) - 2)
        ch[count] -= sizeof(char)-2;
    else
        ch[count] += 2;
}

---

Quote:

---

Originally Posted by laserlight

The catch is that if your string contains the characters '}' or '~', you will end up with unprintable characters.

---

Why are } and ~ unprintable ?

Quote:

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Why are } and ~ unprintable ?

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They are printable, but when you add 2 to them, the result is not printable.

Quote:

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Originally Posted by laserlight

They are printable, but when you add 2 to them, the result is not printable.

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I still don't get it.
'}' has ASCII value 125.
And 127 is a triangle. So it should print a triangle..

~ has value 126
and 128 is C (not the regular C, it has slightly different shape), so it should print that C....:confused:

>> so it should print that C....
Maybe if your consol has the right font.
But in general they are not printable. Try duplicating them on your keyboard. (w/ using the ALT+? method)

????:confused:

In ASCII, 127 is the delete character, so the fact that you 'see' anything is entirely random, depending on your particular set of circumstances.
If you want it to remain printable, look up "rot13" say.

yes i got it. Thanks to all !