Replace an image in C using binary mode

[Savage]

use length in your write as well as your read:
eg
[code=cpp]
fwrite(x, sizeof(x[0]), length, background);
[/code]

Yup,u heard TheMan

;)

Savage

[niskin]

use length in your write as well as your read:
eg
[code=cpp]
fwrite(x, sizeof(x[0]), length, background);
[/code]

I have done this now and the image has still not been transferred. I opened the image in notepad to see if any more had been transferred than before. There are now 3 characters, before there was one.

[Savage]

I have done this now and the image has still not been transferred. I opened the image in notepad to see if any more had been transferred than before. There are now 3 characters, before there was one.

Maybe malloc doesn't allocate enough memory.

Try allocating memory for different data type.

[niskin]

Maybe malloc doesn't allocate enough memory.

Try allocating memory for different data type.

Nope no change when allocating memory for char or float.

[DeMan]

Have you tried printing out the intermediate variables.....
Is the length you get from fseek correct?
What is the size of x?
Can you narrow down whether the read or write is causing the error?

[Savage]

Have you tried printing out the intermediate variables.....
Is the length you get from fseek correct?
What is the size of x?
Can you narrow down whether the read or write is causing the error?

The problem is in length.try printing it out.

Savage

[Savage]

The problem is in length.try printing it out.

Savage

Sorry for double post but I found the frustration maker(tm):

it was fseek:

right now ur fseek is called like:fseek(newp ic,SEEK_END,0) ,but it should be

fseek(newpic,0, SEEK_END)

Savage

[niskin]

Sorry for double post but I found the frustration maker(tm):

it was fseek:

right now ur fseek is called like:fseek(newp ic,SEEK_END,0) ,but it should be

fseek(newpic,0, SEEK_END)

Savage

Right well the content of the file is now: Ä 0 h"0 (when opened in notepad)

It is not displaying any image.

Printing length and x does not work because the compiler is telling me that I'm trying to do an invalid conversion from int to char.

[Savage]

Right well the content of the file is now: Ä 0 h"0 (when opened in notepad)

It is not displaying any image.

Printing length and x does not work because the compiler is telling me that I'm trying to do an invalid conversion from int to char.

How did u tryed to print length?

It should be the same as the size of the file that u are coping

Savage

[niskin]

How did u tryed to print length?

It should be the same as the size of the file that u are coping

Savage

I just did printf( length ).

[Savage]

I just did printf( length ).

Like:

printf("%d",len gth);

??

Savage

[niskin]

Like:

printf("%d",len gth);

??

Savage

Lol I can't believe I missed that, sorry for being stupid. It printed: 101054

I have also just opened stbedes.jpg in notepad again. It appears that it has 4 characters but it seems to have a lot of spaces, and I would guess there are 101050 spaces because that would make up the rest of length and there are so many spaces that it is quite believable. Why is it coming up with 4 characters and 101050 spaces though?

[DeMan]

Incidently (though I don't think this is the cause of your problem),
you are allocating WAY more memory than you need.....
you don't need to multiply (length* sizeof(int)) = the length is already the total number of bytes

[Savage]

Incidently (though I don't think this is the cause of your problem),
you are allocating WAY more memory than you need.....
you don't need to multiply (length* sizeof(int)) = the length is already the total number of bytes

Yes that's true.

However when u remove sizeof(int) final file will have size of 0 bytes,or atleast that's what happens to me.


Savage

[DeMan]

you could use sizeof(char)... .