Reading offset 1

[JFRobishow]

Hi everyone,

I have a small base of C/C++ and know the basis of opening file and outputing to another. I never got real deep in it and I'm wondering if I could code something that would help me do what I need here.

I have a few thousands JPEG all with "file info" from Photoshop in them...using a HEX editor I've been able to find that the offset where the data is stored is always : 140[0x0000008C] and it end at 190 after that it's other stuff like timestamp, etc.

Any ressource somewhere online that would help me code something that would get the file info and then output it in a txt.

Thanks in advance! I appreciate it.

 

[JFRobishow]

Ok started that myself with trial and error mostly.

I created a pointer opened the jpeg for reading and looped through until EOF printing each char with fgetc() and printing with putchar().

Tried opening the file in binary with "rb" and the info I need is printed at the beginning along with everything else though and a bunch of system beep.

I stopped looping until the EOF and specified value myself this time. I see the information I need printed on the screen, but there's also everything that came before it as well and a few chars until I reached the end of the loop.

I'm trying to get information from x to y bytes but can't seem to find any good information on how to do that online at least. Any help is appreciated.

Cheers!

 

[Salem]

Well I would do this (open the file in binary mode)

fseek( fp, 140L, SEEK_SET );      // skip first 140 bytes
for ( i = 0 ; i < 50 ; i++ ) {
  int ch = fgetc( fp );           // read a char
  if ( isprint(ch) ) putchar(ch); // if its printable...
}

--

http://www.catb.org/~esr/faqs/smart-questions.html

 

[JFRobishow]

Thanks Salem that worked perfectly!