IdioSyncracies of feof()........
I wrote the following code and wanted to read 16 bytes each time, in a loop.
while (!feof(filein)) {
nbytes=fread(bufin, 1, 16, filein);
printf("Bytes Read = %d\n", nbytes);
}
I noted that, if the "filein" size is exact multiple of 16 bytes, the
loop runs n times. On the other hand if the "filein" size is not exact
multiple of 16 bytes, the loop runs n-1 times. That cost me 6 hours of
wasted time!
I had a file of 84 bytes. While encrypting my loop ran 6 times. But
unfortunately, encrypted file has to be an exact multiple of 16 bytes,
ie it was 96 bytes. So, While decrypting, the the loop ran 7 times,
making me scratch my head for many hours. Because I wanted to write
same loop for both encrypting and decryption. I could not do so. Then
I had to put my own check, in addition to the feof() check. what a
dumb function, this feof() is. It cannot distinguish that no bytes
are left and it should not run an extra time.
I also tried by putting fread() outside loop and at the end of loop,
but then my encrypting ran one times less :-( So back to square one....
ie putting my own check in the code.
Am I missing something?
regards
shiraz
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