[C] Simple File Crypt - C/C++

GT3X



#include &lt;stdio&#46;h&gt;

#define ENCRYPTION (int)Byte + 30
#define DECRYPTION (int)Byte - 30

int Encrypt(char *file, char* newfile)
{
    FILE *in, *out;
    
    char Byte, newByte;
      
    in = fopen(file, \"rb\");
    out = fopen(newfile, \"w\");
    
    if(in == NULL || out == NULL) 
    {
        printf(\"error in\");
    }
    else 
    {
        printf(\"File opend, Encrypting&#46;&#46;&#46;\");
        while(1)
        {
            printf(\"&#46;\");
            
            if(Byte != EOF)
            {
                Byte=fgetc(in);
                newByte=Byte+30;
                fputc(newByte, out );
            }
            else
            {
                printf(\"End of File\");
                break;
            }
        }
        fclose(in);
        fclose(out);
    }
    
}

int Decrypt(char *file, char *newfile)
{
    FILE *in,*out;
    
    char Byte, newByte;
    
    in = fopen(file, \"rb\");
    out = fopen(newfile, \"w\");
    
    if(in == NULL || out == NULL)
    {
        printf(\"Erro\");
    }
    else
    {
        printf(\"File Opened, Decrypting\");
        while(1)
        {
            printf(\"&#46;\");
            if(Byte!=EOF)
            {
                Byte = fgetc(in);
                newByte = Byte-30;
            }
            else 
            {
                printf(\"End of file\");
                break;
            }
        }
        fclose(in);
        fclose(out);
    }

Xin

Nice share you should comment your code for people that dont know C

Mr. P-teo

Learning C at the min and would help alot if this was commented, nice share though

Praxis

said:

Learning C at the min and would help alot if this was commented, nice share though

Same goes for me, I'd really appreciate it if you commented your code so I can follow it a bit better :)

Deque

I believe you forgot a curly brace at the end.

You didn't provide a main to try this out fast. Make it a bit more convenient for others to use your code. I don't mind missing comments as long as the code is readable. One part of readability is to be consistent. I.e. consistency with naming variables and functions: Sometimes you start with uppercase letters, sometimes you don't.
Consistency with whitespaces: Sometimes you have blanks before and after operators (==, !=, +, -) and assignments (=), sometimes you don't. You really should do something about that.

#define ENCRYPTION (int)Byte + 30
#define DECRYPTION (int)Byte - 30

Why do you define this, but don't use it (apart from that I wouldn't use it, it has no advantage in this case). Delete those lines.

if(in == NULL || out == NULL)
    {
        printf(\"Erro\");
    }

Error messages should be printed to the error stream.

I wonder if you ever ran your Decrypt function, because it only creates an empty file. You forgot the fputc.

int Encrypt(char *file, char* newfile)
int Encrypt(char *file, char* newfile)

You defined return type int for both functions, but you never return anything. If you use gcc as compiler you should compile with -Wall option. That will tell you such things.

Same goes for me, I'd really appreciate it if you commented your code so I can follow it a bit better :)

Rather learn from someone who can actually code.

sangf

said:

You don't close your streams in the if-case.

is it necessary to fclose if fopen returns NULL (ie. because of an error like files not existing)? i can't see the sense, but i suppose it won't hurt.

Deque

said:

said:

You don't close your streams in the if-case.

is it necessary to fclose if fopen returns NULL (ie. because of an error like files not existing)? i can't see the sense, but i suppose it won't hurt.

You are right it isn't necessary. Thank you. Edit: I corrected my post.

Sh3llc0d3

It annoys me when users post code that people are supposed to learn from but hasn't been checked or just isn't up to scratch.

Howdy, Stranger!

Top Posters

Who's Online (0)