[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.

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