Problem reading data from file and record it for use in program

**^xor** · 06-11-2005

My output:

Code:

items = 0, key = "", value = "", n = 0

So what conclusion did we come to?

You can't use %<number>[...] or %*[...]?

Furthermore:

Code:

       n      Nothing is expected; instead, the number of characters  consumed
              thus  far  from  the  input  is stored through the next pointer,
              which must be a pointer to  int.   This  is  not  a  conversion,
              although  it  can be suppressed with the * flag.  The C standard
              says: `Execution of  a  %n  directive  does  not  increment  the
              assignment  count  returned  at the completion of execution' but
              the Corrigendum seems to contradict this. Probably  it  is  wise
              not  to  make any assumptions on the effect of %n conversions on
              the return value.

Now that's just great... *Curses at my K&R book *

**Dave_Sinkula** · 06-11-2005

>So what conclusion did we come to?

That BC55 is broken.

>You can't use %<number>[...] or %*[...]?

...with %n(?).

**^xor** · 06-11-2005

> ...with %n(?).
What does n refer to in the following context:

n [...]If the conversion specification includes an assignment suppressing character or a field width, the behavior is undefined.

I thought it meant that you can't specify a field width for [...], like this:

Code:

%39[...] /* Undefined? */

or suppress the result with *:

Code:

%*[...] /* Undefined? */

And was the code you posted before supposed to work? My output from GCC did not match yours.

**Dave_Sinkula** · 06-11-2005

>What does n refer to in the following context:

I'm taking it to mean that a specifier such as

Code:

"%39[...]%n" // or
"%*[...]%n"

would result in the integer value associated with the %n being undefined.

>And was the code you posted before supposed to work? My output from GCC did not match yours.

It did for me with BC55; that is why I mentioned that it is broken. The first directive should have a matching failure.

**^xor** · 06-11-2005

Understood... Thanks! I wonder why this wasn't in the glibc man pages for scanf on my system though...

**timmer** · 06-12-2005

Wow, a lot replies. Thanks everyone for your support. I will try to write the code using sscanf. I hope that it will work! I will let everyone now, when it works. Thank you all.

Kind Regards,

Allart

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