File Encryption in C

hi again

here's another trouble


I'm encrypting a file using bit manipulation

the program is compiling succesfully.......and executing sucessfully too

but the result is none......it can't make a encrypted file
I'm using VC++6.0 on windows98 and turboc3.0
but it didn't worked out with any of these two.

here's the code


#include<stdio.h>
#include<conio.h>
#include<stdlib.h>

int main()
{
void encrypt();

getch();
return 0;
}

void encrypt()
{
FILE *fs,*ft;
char ch;

fs=fopen("d:\\cprogs\\try.txt","r"); /*normal file */
ft=fopen("d:\\cprogs\\encrypt.txt","w"); /* Encrypted file */

if(fs==NULL||ft==NULL)
{
puts("\nError opening one of the files!!! ");
exit(1);
}

while((ch=fgetc(fs))!=EOF)
fputc(~ch,ft);

fclose(fs);
fclose(ft);

remove("d:\\cprogs\\try.txt");
rename("d:\\cprogs\\encrypt.txt","d:\\windows\\try .txt");
}

It looks like all you're doing is reversing the value of the bits. I actually had better results using fprintf than fputc.

Code:

---

#include <stdio.h>
#include <stdlib.h>

int main( int argc, char *argv[] ) {
        FILE *INSTREAM, *OUTSTREAM;
        char ch;

        if( ( INSTREAM = fopen( argv[1], "r" ) && ( OUTSTREAM = fopen( argv[2], "w" ) ) == NULL){
                printf("Error opening file!");
                exit(1);
        }

        while( fscanf( INSTREAM, "%c", &ch ) != EOF )
                fprintf( OUTSTREAM, "%c", ~ch );

        fclose( INSTREAM );
        fclose( OUTSTREAM );

        return 0;
}

---

> ft=fopen("d:\\cprogs\\encrypt.txt","w"); /* Encrypted file */
This should really be opened in "wb" mode.

> char ch;
And this should be
int ch;
otherwise you might never recognise EOF properly.

> void encrypt();
This is a prototype, not a function call.

To call the function, its just
&nbsp; encrypt();