making data files with gcc

[Dale Walsh]

I'm trying to generate data files however it seems to be prepending  
244 bytes of data and I can't see how to prevent this.

The actual data files are very large and manually using a hex editor  
to generate them isn't appealing considering there are about 300 of  
them.



Here is my test compile session with a reduced file with 2 rows of 10  
bytes so the file should be 32 bytes in length.

test.c: (combined header and source)
___________________________

   typedef struct
   {
     /* # of entries in data */
     int entries;
     /* entry size and count */
     int size;
     int cnt;
     /* data; array of bytes, one row after another. */
     char *data;
   }
   gFast;

/* Location functions take these. */
   typedef gFast * gFastPtr;

char TestDATA[20];

gFast gFastTestRep = {
	2,
	2,
	10,
	TestDATA
};

gFastPtr gFastTest = &gFastTestRep;
/*
    this is all the data
    the file should be 32 bytes in length
   20 bytes of data and 12 bytes for header
*/

char TestDATA[] = {
	
	/* Entry 000 */
	1,2,3,4,5,6,7,8,9,10,

	/* Entry 001 */
	11,12,13,14,15,16,17,18,19,20,
};

___________________________


compiled with:
gcc -pipe -static -c -o test.out test.c

___________________________


Here's the resulting file content, there are always 244 leading bytes  
of data that I can't have, the stuff appended to the end would also  
be nice to not have however it wont interfere with the file being  
valid to the application and isn't as critical.

mustangrestomods:/temp2/clamav-0.80 root# hexdump -vC test.out
00000000  fe ed fa ce 00 00 00 12  00 00 00 00 00 00 00 01   
|................|
00000010  00 00 00 02 00 00 00 d8  00 00 20 00 00 00 00 01   
|.......... .....|
00000020  00 00 00 c0 00 00 00 00  00 00 00 00 00 00 00 00   
|................|
00000030  00 00 00 00 00 00 00 00  00 00 00 28 00 00 00 f4   
|...........(....|
00000040  00 00 00 28 00 00 00 07  00 00 00 07 00 00 00 02  |... 
(............|
00000050  00 00 00 00 5f 5f 74 65  78 74 00 00 00 00 00 00   
|....__text......|
00000060  00 00 00 00 5f 5f 54 45  58 54 00 00 00 00 00 00   
|....__TEXT......|
00000070  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 f4   
|................|
00000080  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   
|................|
00000090  00 00 00 00 00 00 00 00  5f 5f 64 61 74 61 00 00   
|........__data..|
000000a0  00 00 00 00 00 00 00 00  5f 5f 44 41 54 41 00 00   
|........__DATA..|
000000b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 28   
|...............(|
000000c0  00 00 00 f4 00 00 00 02  00 00 01 1c 00 00 00 02   
|................|
000000d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 02   
|................|
000000e0  00 00 00 18 00 00 01 2c  00 00 00 03 00 00 01 50   
|.......,.......P|
000000f0  00 00 00 24 00 00 00 02  00 00 00 02 00 00 00 0a  |... 
$............|
00000100  00 00 00 14 00 00 00 00  01 02 03 04 05 06 07 08   
|................|
00000110  09 0a 0b 0c 0d 0e 0f 10  11 12 13 14 00 00 00 10   
|................|
00000120  00 00 02 40 00 00 00 0c  00 00 02 40 00 00 00 0f   
|...@.......@....|
00000130  0f 02 00 00 00 00 00 14  00 00 00 19 0f 02 00 00   
|................|
00000140  00 00 00 10 00 00 00 01  0f 02 00 00 00 00 00 00   
|................|
00000150  00 5f 67 46 61 73 74 54  65 73 74 52 65 70 00 5f   
|._gFastTestRep._|
00000160  54 65 73 74 44 41 54 41  00 5f 67 46 61 73 74 54  | 
TestDATA._gFastT|
00000170  65 73 74 00                                       |est.|
00000174




-- Dale