1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
#include <sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include "config.h"
#include "outguess.h"
char *progname;
void
usage(void)
{
fprintf(stderr, "%s: <file>\n", progname);
}
void
histogram_simple(u_char *data, int bits)
{
int i;
int one = 0, zero = 0;
for (i = 0; i < bits; i++)
if (TEST_BIT(data, i))
one++;
else
zero++;
fprintf(stdout, "Bits: %6d\n", bits);
fprintf(stdout, "One: %6d, %f\n", one, (float)one/bits);
fprintf(stdout, "Zero: %6d, %f\n", zero, (float)zero/bits);
}
#define MAXRUNLEN 25
void
histogram_runlen(u_char *data, int bits)
{
int buckets[MAXRUNLEN];
int what, count, i;
memset(buckets, 0, sizeof(buckets));
what = TEST_BIT(data, 0);
count = 1;
for (i = 1; i < bits; i++) {
if (TEST_BIT(data, i) != what) {
if (count >= MAXRUNLEN)
count = MAXRUNLEN - 1;
buckets[count]++;
what = TEST_BIT(data, i);
count = 1;
} else
count++;
}
if (count >= MAXRUNLEN)
count = MAXRUNLEN - 1;
buckets[count]++;
for (i = 1; i < MAXRUNLEN; i++) {
fprintf(stdout, "%3d: %6d, %f\n",
i, buckets[i], (float)buckets[i]/bits);
}
}
int
main(int argc, char *argv[])
{
FILE *fin;
char *data;
int bits, bytes, res;
progname = argv[0];
argv++;
argc--;
if (argc != 1) {
usage();
exit(1);
}
if ((fin = fopen(argv[0], "r")) == NULL)
err(1, "fopen");
if ((res = fread(&bits, sizeof(int), 1, fin)) != 1)
err(1, "fread(1): %d", res);
bits = ntohl(bits);
bytes = (bits + 7) / 8;
if ((data = malloc(bytes)) == NULL)
err(1, "malloc");
if ((res = fread(data, sizeof(char), bytes, fin)) != bytes)
err(1, "fread(2): %d", res);
histogram_simple(data, bits);
histogram_runlen(data, bits);
exit(0);
}
|
