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From: Bill Cunningham on 13 Mar 2010 16:20
I am trying to translate this C++ program into C. I don't know if I'm
writing code that would work or not. I am open to any critique.

What they have--

/* chunks.cpp
*
* List the majors chunks of a RIFF file
*
*/
#include <stdio.h>

typedef unsigned char BYTE;
typedef unsigned int DWORD;

int GetLong(char *buf);
void show_list(FILE *in, int length);

int depth = 0;

void indent()
{
int i;
for (i=0; i<depth; i++) printf(" ");
}

class FourCC
{
public:
DWORD code;
int read(FILE *in);
bool Equals(char *str) { return (*(DWORD *)str == code); }
void show();
};

class Chunk
{
public:
FourCC type;
DWORD length;
int read(FILE *in);
void show();
void skip(FILE *in);
bool Equals(char *str) { return (*(DWORD *)str == type.code); }
};

void dump(FILE *in);

int main(int argc, char *argv[])
{
FILE *in;
char *filename;
int i, iret;

if (argc<2) {
printf("usage: chunks filename\n");
return -1;
}
filename = argv[1];
in = fopen(filename,"rb");
printf("filename: %s\n",filename);
if (!in) {
printf("file not found\n");
return -1;
}
Chunk hd;
hd.read(in);
hd.show();
if (hd.Equals("RIFF")) show_list(in,hd.length);
return 0;
}

inline int GetLong(char *buf)
{
return (*(long *)buf);
}

inline short GetShort(char *buf)
{
return (*(short *)buf);
}

void dump(FILE *in)
{
#define BUFSIZE 96
char buf[BUFSIZE];
fread(buf,sizeof(char),BUFSIZE,in);
int i, j, k;
char cp;

for (i=0; i<BUFSIZE; i+=4) {
for (j=0; j<4; j++) {
cp = buf[i+j];
printf("%c",(cp>31?cp:'.'));
}
printf(" %d\n",GetLong(buf+i));
}
}

void show_list(FILE *in, int length)
{
int i, iret, count;
FourCC type;
Chunk ck;
type.read(in);
depth++;
indent();
type.show();
count = 4; // count includes code just read
while (count<length) {
iret = ck.read(in);
if (iret) break;
indent();
ck.show();
if (ck.Equals("LIST")) show_list(in, ck.length);
else ck.skip(in);
count += ck.length+8;
if (ck.length&1) count++; // account for extra odd byte
}
depth--;
indent();
if (iret) printf("*** end of file (%d bytes short)***\n",length-count);
else if (count==length) printf("-----------------\n");
else printf("*** actual %d desired %d ***\n",count,length);
}

int Chunk::read(FILE *in)
{
int i;
char buf[8];
fread(buf,sizeof(char),8,in);
if (feof(in)) return -1;
type.code = GetLong(buf);
length = GetLong(buf+4);
return 0;
}

void Chunk::skip(FILE *in)
{
long nbytes;
nbytes = (length&1? length+1: length); // round up to even word boundary
fseek(in,nbytes,SEEK_CUR);
}


void Chunk::show()
{
DWORD str[2];
str[0] = type.code;
str[1] = 0;
printf("%4s %d\n",(char *)str,length);
}

int FourCC::read(FILE *in)
{
fread((char *) &code,sizeof(FourCC),1,in);
return (feof(in)? -1: 0);
}

void FourCC::show()
{
DWORD str[2];
str[0] = code;
str[1] = 0;
printf("code: %s\n",(char *)str);
}

What I have so far --

#include <stdio.h>
typedef unsigned char BYTE;
typedef unsigned int DWORD;
int getLong(char *buf);
void showList(FILE * in, int length);
int depth = 0;
void indent(void)
{
int i;
for (i = 0; i < depth, i++)
puts(" ");
}
struct FourCC {
DWORD code;
int read(FILE * in);
int Equals(char *str) {
return (*(DWORD *) str == code;
}
void show(void);
} struct Chunk {
struct FourCC type;
DWORD length; int read(FILE * in); void show(void);
void skip(FILE * in);
int Equals(char *str) {
return (*(DWORD *) str == type.code)}
};

void dump(FILE * in);


From: Ian Collins on 13 Mar 2010 17:25
On 03/14/10 10:20 AM, Bill Cunningham wrote:
> I am trying to translate this C++ program into C. I don't know if I'm
> writing code that would work or not. I am open to any critique.

Let the computer do the work:

http://www.comeaucomputing.com/

--
Ian Collins
From: osmium on 13 Mar 2010 17:53
Bill Cunningham wrote:

> I am trying to translate this C++ program into C. I don't know if
> I'm writing code that would work or not. I am open to any critique.
>
> What they have--
>
> /* chunks.cpp
> *
> * List the majors chunks of a RIFF file
> *
> */
> #include <stdio.h>
>
> typedef unsigned char BYTE;
> typedef unsigned int DWORD;
>
> int GetLong(char *buf);
> void show_list(FILE *in, int length);
>
> int depth = 0;
>
> void indent()
> {
> int i;
> for (i=0; i<depth; i++) printf(" ");
> }
>
> class FourCC
> {
> public:
> DWORD code;
> int read(FILE *in);
> bool Equals(char *str) { return (*(DWORD *)str == code); }
> void show();
> };
>
> class Chunk
> {
> public:
> FourCC type;
> DWORD length;
> int read(FILE *in);
> void show();
> void skip(FILE *in);
> bool Equals(char *str) { return (*(DWORD *)str == type.code); }
> };
>
> void dump(FILE *in);
>
> int main(int argc, char *argv[])
> {
> FILE *in;
> char *filename;
> int i, iret;
>
> if (argc<2) {
> printf("usage: chunks filename\n");
> return -1;
> }
> filename = argv[1];
> in = fopen(filename,"rb");
> printf("filename: %s\n",filename);
> if (!in) {
> printf("file not found\n");
> return -1;
> }
> Chunk hd;
> hd.read(in);
> hd.show();
> if (hd.Equals("RIFF")) show_list(in,hd.length);
> return 0;
> }
>
> inline int GetLong(char *buf)
> {
> return (*(long *)buf);
> }
>
> inline short GetShort(char *buf)
> {
> return (*(short *)buf);
> }
>
> void dump(FILE *in)
> {
> #define BUFSIZE 96
> char buf[BUFSIZE];
> fread(buf,sizeof(char),BUFSIZE,in);
> int i, j, k;
> char cp;
>
> for (i=0; i<BUFSIZE; i+=4) {
> for (j=0; j<4; j++) {
> cp = buf[i+j];
> printf("%c",(cp>31?cp:'.'));
> }
> printf(" %d\n",GetLong(buf+i));
> }
> }
>
> void show_list(FILE *in, int length)
> {
> int i, iret, count;
> FourCC type;
> Chunk ck;
> type.read(in);
> depth++;
> indent();
> type.show();
> count = 4; // count includes code just read
> while (count<length) {
> iret = ck.read(in);
> if (iret) break;
> indent();
> ck.show();
> if (ck.Equals("LIST")) show_list(in, ck.length);
> else ck.skip(in);
> count += ck.length+8;
> if (ck.length&1) count++; // account for extra odd byte
> }
> depth--;
> indent();
> if (iret) printf("*** end of file (%d bytes
> short)***\n",length-count); else if (count==length)
> printf("-----------------\n"); else printf("*** actual %d desired %d
> ***\n",count,length);
> }
>
> int Chunk::read(FILE *in)
> {
> int i;
> char buf[8];
> fread(buf,sizeof(char),8,in);
> if (feof(in)) return -1;
> type.code = GetLong(buf);
> length = GetLong(buf+4);
> return 0;
> }
>
> void Chunk::skip(FILE *in)
> {
> long nbytes;
> nbytes = (length&1? length+1: length); // round up to even word
> boundary fseek(in,nbytes,SEEK_CUR);
> }
>
>
> void Chunk::show()
> {
> DWORD str[2];
> str[0] = type.code;
> str[1] = 0;
> printf("%4s %d\n",(char *)str,length);
> }
>
> int FourCC::read(FILE *in)
> {
> fread((char *) &code,sizeof(FourCC),1,in);
> return (feof(in)? -1: 0);
> }
>
> void FourCC::show()
> {
> DWORD str[2];
> str[0] = code;
> str[1] = 0;
> printf("code: %s\n",(char *)str);
> }
>
> What I have so far --
>
> #include <stdio.h>
> typedef unsigned char BYTE;
> typedef unsigned int DWORD;
> int getLong(char *buf);
> void showList(FILE * in, int length);
> int depth = 0;
> void indent(void)
> {
> int i;
> for (i = 0; i < depth, i++)
> puts(" ");
> }
> struct FourCC {
> DWORD code;
> int read(FILE * in);
> int Equals(char *str)

This is not going to fly! fourCC was a class in the original code. You
changed the word to struct. well.... maybe. But then you type a *function*
in as part of the struct! C doesn't allow that. Equals is a function.
Class and struct are not different words for the same thing. I told you
that a week ago. Remember? (read is a function declaration, similar
problem.)



>{
> return (*(DWORD *) str == code;
> }
> void show(void);
> } struct Chunk {
> struct FourCC type;
> DWORD length; int read(FILE * in); void show(void);
> void skip(FILE * in);
> int Equals(char *str) {
> return (*(DWORD *) str == type.code)}
> };
>
> void dump(FILE * in);


From: Bill Cunningham on 14 Mar 2010 13:32

"Ian Collins" <ian-news(a)hotmail.com> wrote in message
news:802hurFrbfU4(a)mid.individual.net...
> Let the computer do the work:
>
> http://www.comeaucomputing.com/
>

I'm not quite sure how to use or what to make of this site Ian. What
exactly am I supposed to do?

Bill


From: osmium on 14 Mar 2010 14:19
Bill Cunningham wrote:

> "Ian Collins" <ian-news(a)hotmail.com> wrote in message
> news:802hurFrbfU4(a)mid.individual.net...
>> Let the computer do the work:
>>
>> http://www.comeaucomputing.com/
>>
>
> I'm not quite sure how to use or what to make of this site Ian.
> What exactly am I supposed to do?

That site has a "try it out" capability. He was suggesting you submit what
you have written for a trial compile. But the site doesn't work with
fragments, and all you have so far is a fragment, so the idea wouldn't work.
Its time for you to pursue Plan B.


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