Thread: null after every character!!?!

Have you verified the file is open, i.e. check the pointer returned by the fopen call?

Originally Posted by the bassinvader

Code:

char trial[50];

...

fgets(trial,200,ptr);

Why are you reading 200 characters worth of data into an array that can only hold 50 characters?

For one thing, this is bad:

Code:

char trial[50];
...
fgets(trial,200,ptr);

You're telling fgets to read up to 199 characters, but your array is only 50 elements big.

EDIT: beaten again!

I'm not exactly sure what you're trying to do, but I'm positive printf starts failing because it expects an integer, yet you passed in characters.

> fgets(trial,200,ptr);
fgets can be as bad as gets if you are not honest about your string sizes.

Try something like this, perhaps:

Code:

#include <stdio.h>
#include <ctype.h>

int main ( void )
{
   int i;
   char trial[50];
   const char filename[] = "C:/at.txt";
   FILE *ptr = fopen(filename, "r");
   if( ptr != NULL )
   {
      fgets(trial, sizeof trial, ptr);
      for( i = 0; i < sizeof trial; ++i )
      {
         putchar( isprint(trial[i]) ? trial[i] : '.' );
      }
    fclose(ptr);
   }
   else
   {
     perror(filename);
   }
   return 0;
}

$ ./foo
This is a sample...a......................"..5.a.v

It's kind of goofy if you insist on printing the whole buffer, and not just what you can read.

I'm positive printf starts failing because it expects an integer, yet you passed in characters.

Character, integer...same difference. Characters just have a smaller range.

Originally Posted by SirNot

Just an idea, but if the file is unicode encoded something like that might happen.

I second this. My first thought was "Hey, must be a unicode text file."

If it is a unicode file, then ordinary fgets() isn't going to read past the first nul (as far as I know).

> char trial[50];
Try
memset( trial, '@', sizeof trial );
fgets( trial, sizeof trial, fp );

At least then you'll have a reasonable chance of seeing how much data you really read from the file, and how much is just "garbage" in your otherwise uninitialised char array.

Originally Posted by Salem

If it is a unicode file, then ordinary fgets() isn't going to read past the first nul (as far as I know).

Why not? You're telling fgets how much to read, not to look for a null delimiter. fgets stops reading on a new line, EOF, or when it hits count - 1.

Originally Posted by the bassinvader

Finally i must admit total ignorance of you're referals to unicode so could someone send me to a place to educate myself?

I could have sworn I already posted a link.

Who knows? This is programming, not cooking.

I have programmed for over a year and I have not learned much about Unicode yet. There isn't any real need at this point. If you're writing internationalized applications et al, then you have a good reason to learn non-ASCII encodings. For now, you should be working on programming basics.

You should stop writing programs which look like IOCCC entries -- space them out, structure them a little. Check out Salem's avatar too.

Originally Posted by the bassinvader

Yeah you did post a link sorry.

In my haste to reply i overlooked it. Thanx

But i gotta admit that i feel a little bogged down in things that i dont really understand.
I'm just a learner so i just need a little help understanding why the program doesnt do what i was expecting, i mean its not exactly difficult code is it!! And why do programs that previously worked fine now go mad?

It definately sounds like you saved the text in Unicode (specifically UTF-16). It uses 16 bits (2 bytes) for each letter, and for any ASCII character, the high-order byte is zero. You can always open notepad and see how it's saving them (ANSI or Unicode) in the file->save options.

Get a good hex editor and take a look at the data file itself -- that should tell you if the problem is with your reading of the file or the underlying file itself.