It was just a memory aid when reading C code

L

Logan Lee

BACKGROUND READING:
http://www.geocities.com/logan.lee30/a_crude_method_of_static_code_analysis.html
http://www.geocities.com/logan.lee30/A_method_of_static_code_analysis.html

Like this:

CODE:
#include "sort.h"
40
41
#ifndef lint
42
__RCSID("$NetBSD: append.c,v 1.10 2001/02/19 20:50:17 jdolecek Exp $");
43
__SCCSID("@(#)append.c 8.1 (Berkeley) 6/6/93");
44
#endif /* not lint */
45
46
#include <stdlib.h>
47
#include <string.h>
48
49
#define OUTPUT { \
50
if ((n = cpos - ppos) > 1) { \
51
for (; ppos < cpos; ++ppos) \
52
*ppos -= odepth; \
53
ppos -= n; \
54
if (stable_sort) \
55
sradixsort(ppos, n, wts1, REC_D); \
56
else \
57
radixsort(ppos, n, wts1, REC_D); \
58
for (; ppos < cpos; ppos++) { \
59
prec = (const RECHEADER *) (*ppos - sizeof(TRECHEADER));\
60
put(prec, fp); \
61
} \
62
} else put(prec, fp); \
63
}
64
65
/*
66
* copy sorted lines to output; check for uniqueness
67
*/
68
void
69
append(keylist, nelem, depth, fp, put, ftbl)
70
const u_char **keylist;
71
int nelem;
72
int depth;
73
FILE *fp;
74
put_func_t put;
75
struct field *ftbl;
76
{
77
u_char *wts, *wts1;
78
int n, odepth=0;
79
const u_char **cpos, **ppos, **lastkey;
80
const u_char *cend, *pend, *start;
81
const struct recheader *crec, *prec;
82
83
if (*keylist == '\0' && UNIQUE)
84
return;
85
wts1 = wts = ftbl[0].weights;
86
if ((!UNIQUE) && SINGL_FLD) {
87
if ((ftbl[0].flags & F) && (ftbl[0].flags & R))
88
wts1 = Rascii;
89
else if (ftbl[0].flags & F)
90
wts1 = ascii;
91
odepth = depth;
92
}
93
lastkey = keylist + nelem;
94
depth += sizeof(TRECHEADER);
95
if (SINGL_FLD && (UNIQUE || wts1 != wts)) {
96
ppos = keylist;
97
prec = (const RECHEADER *) (*ppos - depth);
98
if (UNIQUE)
99
put(prec, fp);
100
for (cpos = &keylist[1]; cpos < lastkey; cpos++) {
101
crec = (const RECHEADER *) (*cpos - depth);
102
if (crec->length == prec->length) {
103
/*
104
* Set pend and cend so that trailing NUL and
105
* record separator is ignored.
106
*/
107
pend = (const u_char *) &prec->data + prec->length - 2;
108
cend = (const u_char *) &crec->data + crec->length - 2;
109
for (start = *cpos; cend >= start; cend--) {
110
if (wts[*cend] != wts[*pend])
111
break;
112
pend--;
113
}
114
if (pend + 1 != *ppos) {
115
if (!UNIQUE) {
116
OUTPUT;
117
} else
118
put(crec, fp);
119
ppos = cpos;
120
prec = crec;
121
}
122
} else {
123
if (!UNIQUE) {
124
OUTPUT;
125
} else
126
put(crec, fp);
127
ppos = cpos;
128
prec = crec;
129
}
130
}
131
if (!UNIQUE) { OUTPUT; }
132
} else if (UNIQUE) {
133
ppos = keylist;
134
prec = (const RECHEADER *) (*ppos - depth);
135
put(prec, fp);
136
for (cpos = &keylist[1]; cpos < lastkey; cpos++) {
137
crec = (const RECHEADER *) (*cpos - depth);
138
if (crec->offset == prec->offset) {
139
/*
140
* Set pend and cend so that trailing NUL and
141
* record separator is ignored.
142
*/
143
pend = (const u_char *) &prec->data + prec->offset - 2;
144
cend = (const u_char *) &crec->data + crec->offset - 2;
145
for (start = *cpos; cend >= start; cend--) {
146
if (wts[*cend] != wts[*pend])
147
break;
148
pend--;
149
}
150
if (pend + 1 != *ppos) {
151
ppos = cpos;
152
prec = crec;
153
put(prec, fp);
154
}
155
} else {
156
ppos = cpos;
157
prec = crec;
158
put(prec, fp);
159
}
160
}
161
} else for (cpos = keylist; cpos < lastkey; cpos++) {
162
crec = (const RECHEADER *) (*cpos - depth);
163
put(crec, fp);
164
}
165
}
166
167
/*
168
* output the already sorted eol bin.
169
*/
170
void
171
rd_append(binno, infl0, nfiles, outfp, buffer, bufend)
172
u_char *buffer;
173
int infl0;
174
int binno, nfiles;
175
FILE *outfp;
176
u_char *bufend;
177
{
178
RECHEADER *rec;
179
180
rec = (RECHEADER *) buffer;
181
if (!getnext(binno, infl0, NULL, nfiles,
182
(RECHEADER *) buffer, bufend, 0)) {
183
putline(rec, outfp);
184
while (getnext(binno, infl0, NULL, nfiles, (RECHEADER *) buffer,
185
bufend, 0) == 0) {
186
if (!UNIQUE)
187
putline(rec, outfp);
188
}
189
}
190
}
191
192
/*
193
* append plain text--used after sorting the biggest bin.
194
*/
195
void
196
concat(a, b)
197
FILE *a, *b;
198
{
199
int nread;
200
char buffer[4096];
201
202
rewind(b);
203
while ((nread = fread(buffer, 1, 4096, b)) > 0)
204
EWRITE(buffer, 1, nread, a);
205
}

------------------------------------
SUMMARY:
sort
append.c
#include 3
#define OUTPUT
(I)[2]((I))_1[1,2,1]

append 6 200101
10211
I
I(I)[2]
(I)[3]((I))_2[1,1,1]
(I)[2]((I))_1[1,1]I
(I)[2]
(I)[2]
F(I)[2]((I))_1[1,1]I
F

rd_append 6 10011
1
IWI

concat 2 11
01
W
 
L

Logan Lee

Mon, 24 Dec 2007 05:32:54 +0000ì—, Logan Lee ì¼ìŠµë‹ˆë‹¤:
BACKGROUND READING:
http://www.geocities.com/logan.lee30/a_crude_method_of_static_code_analysis.html
http://www.geocities.com/logan.lee30/A_method_of_static_code_analysis.html

Like this:

CODE:
#include "sort.h"
40
41
#ifndef lint
42
__RCSID("$NetBSD: append.c,v 1.10 2001/02/19 20:50:17 jdolecek Exp $");
43
__SCCSID("@(#)append.c 8.1 (Berkeley) 6/6/93");
44
#endif /* not lint */
45
46
#include <stdlib.h>
47
#include <string.h>
48
49
#define OUTPUT { \
50
if ((n = cpos - ppos) > 1) { \
51
for (; ppos < cpos; ++ppos) \
52
*ppos -= odepth; \
53
ppos -= n; \
54
if (stable_sort) \
55
sradixsort(ppos, n, wts1, REC_D); \
56
else \
57
radixsort(ppos, n, wts1, REC_D); \
58
for (; ppos < cpos; ppos++) { \
59
prec = (const RECHEADER *) (*ppos - sizeof(TRECHEADER));\
60
put(prec, fp); \
61
} \
62
} else put(prec, fp); \
63
}
64
65
/*
66
* copy sorted lines to output; check for uniqueness
67
*/
68
void
69
append(keylist, nelem, depth, fp, put, ftbl)
70
const u_char **keylist;
71
int nelem;
72
int depth;
73
FILE *fp;
74
put_func_t put;
75
struct field *ftbl;
76
{
77
u_char *wts, *wts1;
78
int n, odepth=0;
79
const u_char **cpos, **ppos, **lastkey;
80
const u_char *cend, *pend, *start;
81
const struct recheader *crec, *prec;
82
83
if (*keylist == '\0' && UNIQUE)
84
return;
85
wts1 = wts = ftbl[0].weights;
86
if ((!UNIQUE) && SINGL_FLD) {
87
if ((ftbl[0].flags & F) && (ftbl[0].flags & R))
88
wts1 = Rascii;
89
else if (ftbl[0].flags & F)
90
wts1 = ascii;
91
odepth = depth;
92
}
93
lastkey = keylist + nelem;
94
depth += sizeof(TRECHEADER);
95
if (SINGL_FLD && (UNIQUE || wts1 != wts)) {
96
ppos = keylist;
97
prec = (const RECHEADER *) (*ppos - depth);
98
if (UNIQUE)
99
put(prec, fp);
100
for (cpos = &keylist[1]; cpos < lastkey; cpos++) {
101
crec = (const RECHEADER *) (*cpos - depth);
102
if (crec->length == prec->length) {
103
/*
104
* Set pend and cend so that trailing NUL and
105
* record separator is ignored.
106
*/
107
pend = (const u_char *) &prec->data + prec->length - 2;
108
cend = (const u_char *) &crec->data + crec->length - 2;
109
for (start = *cpos; cend >= start; cend--) {
110
if (wts[*cend] != wts[*pend])
111
break;
112
pend--;
113
}
114
if (pend + 1 != *ppos) {
115
if (!UNIQUE) {
116
OUTPUT;
117
} else
118
put(crec, fp);
119
ppos = cpos;
120
prec = crec;
121
}
122
} else {
123
if (!UNIQUE) {
124
OUTPUT;
125
} else
126
put(crec, fp);
127
ppos = cpos;
128
prec = crec;
129
}
130
}
131
if (!UNIQUE) { OUTPUT; }
132
} else if (UNIQUE) {
133
ppos = keylist;
134
prec = (const RECHEADER *) (*ppos - depth);
135
put(prec, fp);
136
for (cpos = &keylist[1]; cpos < lastkey; cpos++) {
137
crec = (const RECHEADER *) (*cpos - depth);
138
if (crec->offset == prec->offset) {
139
/*
140
* Set pend and cend so that trailing NUL and
141
* record separator is ignored.
142
*/
143
pend = (const u_char *) &prec->data + prec->offset - 2;
144
cend = (const u_char *) &crec->data + crec->offset - 2;
145
for (start = *cpos; cend >= start; cend--) {
146
if (wts[*cend] != wts[*pend])
147
break;
148
pend--;
149
}
150
if (pend + 1 != *ppos) {
151
ppos = cpos;
152
prec = crec;
153
put(prec, fp);
154
}
155
} else {
156
ppos = cpos;
157
prec = crec;
158
put(prec, fp);
159
}
160
}
161
} else for (cpos = keylist; cpos < lastkey; cpos++) {
162
crec = (const RECHEADER *) (*cpos - depth);
163
put(crec, fp);
164
}
165
}
166
167
/*
168
* output the already sorted eol bin.
169
*/
170
void
171
rd_append(binno, infl0, nfiles, outfp, buffer, bufend)
172
u_char *buffer;
173
int infl0;
174
int binno, nfiles;
175
FILE *outfp;
176
u_char *bufend;
177
{
178
RECHEADER *rec;
179
180
rec = (RECHEADER *) buffer;
181
if (!getnext(binno, infl0, NULL, nfiles,
182
(RECHEADER *) buffer, bufend, 0)) {
183
putline(rec, outfp);
184
while (getnext(binno, infl0, NULL, nfiles, (RECHEADER *) buffer,
185
bufend, 0) == 0) {
186
if (!UNIQUE)
187
putline(rec, outfp);
188
}
189
}
190
}
191
192
/*
193
* append plain text--used after sorting the biggest bin.
194
*/
195
void
196
concat(a, b)
197
FILE *a, *b;
198
{
199
int nread;
200
char buffer[4096];
201
202
rewind(b);
203
while ((nread = fread(buffer, 1, 4096, b)) > 0)
204
EWRITE(buffer, 1, nread, a);
205
}

------------------------------------
SUMMARY:
sort
append.c
#include 3
#define OUTPUT
(I)[2]((I))_1[1,2,1]

append 6 200101
10211
I
I(I)[2]
(I)[3]((I))_2[1,1,1]
(I)[2]((I))_1[1,1]I
(I)[2]
(I)[2]
F(I)[2]((I))_1[1,1]I
F

rd_append 6 10011
1
IWI

concat 2 11
01
W
Click to expand...

http://www.geocities.com/logan.lee30/code_example.pdf
 
T

Thad Smith

Logan said:
BACKGROUND READING:
http://www.geocities.com/logan.lee30/a_crude_method_of_static_code_analysis.html
http://www.geocities.com/logan.lee30/A_method_of_static_code_analysis.html

Like this:

CODE:
#include "sort.h"
40
41
#ifndef lint
42
__RCSID("$NetBSD: append.c,v 1.10 2001/02/19 20:50:17 jdolecek Exp $");
43
__SCCSID("@(#)append.c 8.1 (Berkeley) 6/6/93");
44 ....
------------------------------------
SUMMARY:
sort
append.c
#include 3
#define OUTPUT
(I)[2]((I))_1[1,2,1]

append 6 200101
10211
I
I(I)[2]
(I)[3]((I))_2[1,1,1]
(I)[2]((I))_1[1,1]I
(I)[2]
(I)[2]
F(I)[2]((I))_1[1,1]I
F

rd_append 6 10011
1
IWI

concat 2 11
01
W
Click to expand...

Whatever your point was, it didn't come across. Perhaps this is useful for
something, but it isn't apparent to me from your post or reference. You
haven't explained what you are trying to achieve.
 

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