xref: /freebsd/contrib/gdtoa/g__fmt.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /****************************************************************
2 
3 The author of this software is David M. Gay.
4 
5 Copyright (C) 1998 by Lucent Technologies
6 All Rights Reserved
7 
8 Permission to use, copy, modify, and distribute this software and
9 its documentation for any purpose and without fee is hereby
10 granted, provided that the above copyright notice appear in all
11 copies and that both that the copyright notice and this
12 permission notice and warranty disclaimer appear in supporting
13 documentation, and that the name of Lucent or any of its entities
14 not be used in advertising or publicity pertaining to
15 distribution of the software without specific, written prior
16 permission.
17 
18 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
20 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
21 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
23 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
24 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
25 THIS SOFTWARE.
26 
27 ****************************************************************/
28 
29 /* Please send bug reports to David M. Gay (dmg at acm dot org,
30  * with " at " changed at "@" and " dot " changed to ".").	*/
31 
32 #include "gdtoaimp.h"
33 
34 #ifdef USE_LOCALE
35 #include "locale.h"
36 #endif
37 
38  char *
39 #ifdef KR_headers
40 g__fmt(b, s, se, decpt, sign, blen) char *b; char *s; char *se; int decpt; ULong sign; size_t blen;
41 #else
42 g__fmt(char *b, char *s, char *se, int decpt, ULong sign, size_t blen)
43 #endif
44 {
45 	int i, j, k;
46 	char *be, *s0;
47 	size_t len;
48 #ifdef USE_LOCALE
49 #ifdef NO_LOCALE_CACHE
50 	char *decimalpoint = localeconv()->decimal_point;
51 	size_t dlen = strlen(decimalpoint);
52 #else
53 	char *decimalpoint;
54 	static char *decimalpoint_cache;
55 	static size_t dlen;
56 	if (!(s0 = decimalpoint_cache)) {
57 		s0 = localeconv()->decimal_point;
58 		dlen = strlen(s0);
59 		if ((decimalpoint_cache = (char*)MALLOC(strlen(s0) + 1))) {
60 			strcpy(decimalpoint_cache, s0);
61 			s0 = decimalpoint_cache;
62 			}
63 		}
64 	decimalpoint = s0;
65 #endif
66 #else
67 #define dlen 0
68 #endif
69 	s0 = s;
70 	len = (se-s) + dlen + 6; /* 6 = sign + e+dd + trailing null */
71 	if (blen < len)
72 		goto ret0;
73 	be = b + blen - 1;
74 	if (sign)
75 		*b++ = '-';
76 	if (decpt <= -4 || decpt > se - s + 5) {
77 		*b++ = *s++;
78 		if (*s) {
79 #ifdef USE_LOCALE
80 			while((*b = *decimalpoint++))
81 				++b;
82 #else
83 			*b++ = '.';
84 #endif
85 			while((*b = *s++) !=0)
86 				b++;
87 			}
88 		*b++ = 'e';
89 		/* sprintf(b, "%+.2d", decpt - 1); */
90 		if (--decpt < 0) {
91 			*b++ = '-';
92 			decpt = -decpt;
93 			}
94 		else
95 			*b++ = '+';
96 		for(j = 2, k = 10; 10*k <= decpt; j++, k *= 10){}
97 		for(;;) {
98 			i = decpt / k;
99 			if (b >= be)
100 				goto ret0;
101 			*b++ = i + '0';
102 			if (--j <= 0)
103 				break;
104 			decpt -= i*k;
105 			decpt *= 10;
106 			}
107 		*b = 0;
108 		}
109 	else if (decpt <= 0) {
110 #ifdef USE_LOCALE
111 		while((*b = *decimalpoint++))
112 			++b;
113 #else
114 		*b++ = '.';
115 #endif
116 		if (be < b - decpt + (se - s))
117 			goto ret0;
118 		for(; decpt < 0; decpt++)
119 			*b++ = '0';
120 		while((*b = *s++) != 0)
121 			b++;
122 		}
123 	else {
124 		while((*b = *s++) != 0) {
125 			b++;
126 			if (--decpt == 0 && *s) {
127 #ifdef USE_LOCALE
128 				while(*b = *decimalpoint++)
129 					++b;
130 #else
131 				*b++ = '.';
132 #endif
133 				}
134 			}
135 		if (b + decpt > be) {
136  ret0:
137 			b = 0;
138 			goto ret;
139 			}
140 		for(; decpt > 0; decpt--)
141 			*b++ = '0';
142 		*b = 0;
143 		}
144  ret:
145 	freedtoa(s0);
146 	return b;
147  	}
148