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#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
typedef struct
{
int len;
unsigned char *addr;
} Block;
static int Word(FILE *fp)
{
int i0;
int i1;
i0 = getc(stdin);
i1 = getc(stdin);
return i0 | i1 << 8;
}
static int Triplet(FILE *fp)
{
int i0;
int i1;
int i2;
i0 = getc(stdin);
i1 = getc(stdin);
i2 = getc(stdin);
return i0 | i1 << 8 | i2 << 16;
}
static Block *DumpBlock(FILE *fp)
{
Block *block;
Word(fp); /* PILOT */
Word(fp); /* SYNC1 */
Word(fp); /* SYNC2 */
Word(fp); /* ZERO */
Word(fp); /* ONE */
Word(fp); /* PILOT LEN */
getc(fp); /* USED BITS */
Word(fp); /* PAUSE */
block = malloc(sizeof *block);
block->len = Triplet(fp); /* LEN */
block->addr = malloc(block->len);
fread(block->addr, 1, block->len, fp);
return block;
}
static void CompareEnds(Block **block, int count)
{
int f;
int n;
int min;
int done;
min = 0xffffff;
for(f=0; f < count; f++)
{
if (block[f]->len < min)
{
min = block[f]->len;
}
}
done = 0;
for(f = 0; f < min && !done; f++)
{
for(n = 0; n < count - 1 && !done; n++)
{
int diff;
diff = (int)block[n]->addr[block[n]->len - 1 - f] -
(int)block[n+1]->addr[block[n+1]->len - 1 - f];
if (abs(diff) > 5)
{
done = 1;
}
}
}
if (done)
{
printf("Last %d bytes match\n", --f);
for(n = 0; n < f; n++)
{
if (n > 0)
{
printf(" ");
}
printf("%x", (unsigned)block[0]->addr[block[0]->len - 1 - n]);
}
printf("\n");
}
}
int main(int argc, char *argv)
{
int ch;
int count;
int f;
Block *block[256] = {0};
ch = getc(stdin);
while(ch != EOF)
{
if (ch == 0x11)
{
block[count++] = DumpBlock(stdin);
}
ch = getc(stdin);
}
printf("Got %d blocks\n", count);
CompareEnds(block, count);
}
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