Hello everyone, merry christmas!

I have some questions about the following program:

arrtest.c
------------

#include

int main(int agc, char *argv[]) {
int array2d[2][2] = { {1,2} , {3,4} };
int (* arrp)[2] = array2d;

printf("&array2d = %%p\tarray2d = %%p\t*array2d = %%p\n", &array2d,
array2d, *array2d);
printf("&arrp = %%p\tarp = %%p\t*arrp = %%p\t**arp = %%d\n", &arrp,
arrp, *arrp, **arrp);

return 0;
}

When I compile and run the program I get the following results:

&array2d = 0xbfd9e880 array2d = 0xbfd9e880 *array2d = 0xbfd9e880
&arrp = 0xbfd9e890 arrp = 0xbfd9e880 *arrp =
0xbfd9e880 **arrp = 1

My questions are:

hi all,

Can anybody explain about setjump and longjump functions if u have
time to spend on this.

Thanks,
pal

Hi,

How does the memory management function 'free()' frees the memory
pointed by a pointer variable at run time. how does it know the size.
if there is way when free() can do, then why can't we do it
externally?.

Thanks
Panduranga Chary

Hi everyone:
I have a question in using Callback function, there is my code:

/******* code start *********/
#include

void a();
void b();
void run();
int state;

int main()
{
state = 0;
run();
}

I have an open source Windows program I would like to port to
FreeBSD. I tried compiling it 'as is' and, so far, it only trips up
on MS/Windows definitions, such as 'ulong'. Is there a cross-check
list to find equivalent typedefs, defines, etc. between gcc and
Windows stuff? Is there a software 'converter' of sorts, too?

Hi,
I am passing a tcpdump filter to a function which compiles the filter
using pcap_compile and then sets it.
Here is the filter,

ip[12:4]>=0x0000 and ip[12:4] <=0xd9295a3 and ip[16:4] >=0x0000 and
ip[16:4] <=0x3ca9b416 and tcp[0:2]>=0 and tcp[0:2]<=23923 and
tcp[2:2]>=0 and tcp[2:2]<=64582 and tcp[2:2]<=655355

I have many threads passing different filters of a similar form to
the same function.

The problem is, 8 out of 10 times, the string gets passed successfully
and compiled without any problem, but the 2 times, the string gets
manipulated in a random manner.

For example, in this case, the filter was passed as

ip[12:4]>=0x0000 and ip[12:4] <=0xd9295a3 and ip[16:4] >=0x0000 and
ip[16:4] <=0x3ca9b416 and tcp[0:2]>=0 and tcp[0:2]<=23923 and
tcp[2:2]>=0 and tcp[2:2]<=64582 tcp[2:2]<=655355

which of course resulted in pcap_compile raising a syntax error.

Here is a part of the output for 10 threads:

ip[12:4]>=0x0000 and ip[12:4] <=0x4e82b543 and ip[16:4] >=0x0000 and
ip[16:4] <=0x6f835b87 and tcp[0:2]>=0 and tcp[0:2]<=13052 and
tcp[2:2]>=0 and tcp[2:2]<=14069n
Couldn't parse filter ip[12:4]>=0x0000...

Hello,

I am looking for some advice/guidance on using the FFTW (fftw.org)
package to do 2D FFT on some bitmap images. I have bitmaps broken up
into small fragments and need to perform the 2D FFT on each of those.
The documentation on performing this task is a bit sparse so I figured
my best luck would be to turn to the newsgroups.

Thanks

In my "Happy Christmas" message, I proposed a function to read
a file into a RAM buffer and return that buffer or NULL if
the file doesn't exist or some other error is found.

It is interesting to see that the answers to that message prove that
programming exclusively in standard C is completely impossible even
for a small and ridiculously simple program like the one I proposed.

1 I read the file contents in binary mode, what should allow me
to use ftell/fseek to determine the file size.

No objections to this were raised, except of course the obvious
one, if the "file" was some file associated with stdin, for
instance under some unix machine /dev/tty01 or similar...

I did not test for this since it is impossible in standard C:
isatty() is not in the standard.

2) There is NO portable way to determine which characters should be
ignored when transforming a binary file into a text file. One
reader (CB Falconer) proposed to open the file in binary mode
and then in text mode and compare the two buffers to see which
characters were missing... Well, that would be too expensive.

I was doing a little bit of reading in the ISO C spec. about
typecasting to a void type. This caused me to have a question. In
particular, I'm curious to know about section 6.3.2.2 where the specs
says "is evaluated as a void expression, its value or designator is
discarded."

If I do the following:

#include

int
main(int argc, char **argv)
{
int s = 12;

printf("non-void type = 0x%%x\n", s);

(void)s;

return(0);
}

What is the effect of typecasting s to a void type. Does the compiler
just treat the line as a null statement?

Thanks.

-brad walker