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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
/*
Unix snprintf implementation.
Version 1.1
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Revision History:
sitecopy changes:
added sys/types.h include to pick up size_t define.
renamed dtoa -> doubletoa to avoid dtoa conflict with cygwin.
1.1:
* added changes from Miles Bader
* corrected a bug with %f
* added support for %#g
* added more comments :-)
1.0:
* supporting must ANSI syntaxic_sugars(see below)
0.0:
* suppot %s %c %d
it understands:
Integer:
%lu %lu %u
%hd %ld %d decimal
%ho %lo %o octal
%hx %lx %x %X hexa
Floating points:
%g %G %e %E %f double
Strings:
%s %c string
%% %
Formating conversion flags:
- justify left
+ Justify right or put a plus if number
# prefix 0x, 0X for hexa and 0 for octal
* precision/witdth is specify as an (int) in the arguments
' ' leave a blank for number with no sign
l the later should be a long
h the later should be a short
format:
snprintf(holder, sizeof_holder, format, ...)
Return values:
(sizeof_holder - 1)
THANKS(for the patches and ideas):
Miles Bader
Cyrille Rustom
Jacek Slabocewiz
Mike Parker(mouse)
Alain Magloire: alainm@rcsm.ee.mcgill.ca
*/
#if defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__
/**** changed for sitecopy ****/
#include <sys/types.h>
#include <stdarg.h>
#else
#include <varargs.h>
#endif
/*
* For the FLOATING POINT FORMAT :
* the challenge was finding a way to
* manipulate the Real numbers without having
* to resort to mathematical function(it
* would require to link with -lm) and not
* going down to the bit pattern(not portable)
*
* so a number, a real is:
real = integral + fraction
integral = ... + a(2)*10^2 + a(1)*10^1 + a(0)*10^0
fraction = b(1)*10^-1 + b(2)*10^-2 + ...
where:
0 <= a(i) => 9
0 <= b(i) => 9
from then it was simple math
*/
/*
* size of the buffer for the integral part
* and the fraction part
*/
#define MAX_INT 99 + 1 /* 1 for the null */
#define MAX_FRACT 29 + 1
/*
* numtoa() uses PRIVATE buffers to store the results,
* So this function is not reentrant
*/
#define itoa(n) numtoa(n, 10, 0, (char **)0)
#define otoa(n) numtoa(n, 8, 0, (char **)0)
#define htoa(n) numtoa(n, 16, 0, (char **)0)
#define doubletoa(n, p, f) numtoa(n, 10, p, f)
#define SWAP_INT(a,b) {int t; t = (a); (a) = (b); (b) = t;}
/* this struct holds everything we need */
struct DATA {
int length;
char *holder;
int counter;
#ifdef __STDC__
const char *pf;
#else
char *pf;
#endif
/* FLAGS */
int width, precision;
int justify; char pad;
int square, space, star_w, star_p, a_long ;
};
#define PRIVATE static
#define PUBLIC extern
/* signature of the functions */
#ifdef __STDC__
/* the floating point stuff */
PRIVATE double pow_10(int);
PRIVATE int log_10(double);
PRIVATE double integral(double, double *);
PRIVATE char * numtoa(double, int, int, char **);
/* for the format */
PRIVATE void conv_flag(char *, struct DATA *);
PRIVATE void floating(struct DATA *, double);
PRIVATE void exponent(struct DATA *, double);
PRIVATE void decimal(struct DATA *, double);
PRIVATE void octal(struct DATA *, double);
PRIVATE void hexa(struct DATA *, double);
PRIVATE void strings(struct DATA *, char *);
#else
/* the floating point stuff */
PRIVATE double pow_10();
PRIVATE int log_10();
PRIVATE double integral();
PRIVATE char * numtoa();
/* for the format */
PRIVATE void conv_flag();
PRIVATE void floating();
PRIVATE void exponent();
PRIVATE void decimal();
PRIVATE void octal();
PRIVATE void hexa();
PRIVATE void strings();
#endif
/* those are defines specific to snprintf to hopefully
* make the code clearer :-)
*/
#define RIGHT 1
#define LEFT 0
#define NOT_FOUND -1
#define FOUND 1
#define MAX_FIELD 15
/* the conversion flags */
#define isflag(c) ((c) == '#' || (c) == ' ' || \
(c) == '*' || (c) == '+' || \
(c) == '-' || (c) == '.' || \
isdigit(c))
/* round off to the precision */
#define ROUND(d, p) \
(d < 0.) ? \
d - pow_10(-(p)->precision) * 0.5 : \
d + pow_10(-(p)->precision) * 0.5
/* set default precision */
#define DEF_PREC(p) \
if ((p)->precision == NOT_FOUND) \
(p)->precision = 6
/* put a char */
#define PUT_CHAR(c, p) \
if ((p)->counter < (p)->length) { \
*(p)->holder++ = (c); \
(p)->counter++; \
}
#define PUT_PLUS(d, p) \
if ((d) > 0. && (p)->justify == RIGHT) \
PUT_CHAR('+', p)
#define PUT_SPACE(d, p) \
if ((p)->space == FOUND && (d) > 0.) \
PUT_CHAR(' ', p)
/* pad right */
#define PAD_RIGHT(p) \
if ((p)->width > 0 && (p)->justify != LEFT) \
for (; (p)->width > 0; (p)->width--) \
PUT_CHAR((p)->pad, p)
/* pad left */
#define PAD_LEFT(p) \
if ((p)->width > 0 && (p)->justify == LEFT) \
for (; (p)->width > 0; (p)->width--) \
PUT_CHAR((p)->pad, p)
/* if width and prec. in the args */
#define STAR_ARGS(p) \
if ((p)->star_w == FOUND) \
(p)->width = va_arg(args, int); \
if ((p)->star_p == FOUND) \
(p)->precision = va_arg(args, int)
PUBLIC int
#if defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__
snprintf(char *string, size_t length, const char * format, ...);
#else
snprintf(string, length, format, va_alist);
char *string;
size_t length;
char * format;
va_dcl
#endif
|