1 /*
2 Copyright (c) 1990 Regents of the University of California.
3 All rights reserved.
4 */
5 /*
6 FUNCTION
7 <<ecvt>>, <<ecvtf>>, <<fcvt>>, <<fcvtf>>---double or float to string
8
9 INDEX
10 ecvt
11 INDEX
12 ecvtf
13 INDEX
14 fcvt
15 INDEX
16 fcvtf
17
18 SYNOPSIS
19 #include <stdlib.h>
20
21 char *ecvt(double <[val]>, int <[chars]>, int *<[decpt]>, int *<[sgn]>);
22 char *ecvtf(float <[val]>, int <[chars]>, int *<[decpt]>, int *<[sgn]>);
23
24 char *fcvt(double <[val]>, int <[decimals]>,
25 int *<[decpt]>, int *<[sgn]>);
26 char *fcvtf(float <[val]>, int <[decimals]>,
27 int *<[decpt]>, int *<[sgn]>);
28
29 DESCRIPTION
30 <<ecvt>> and <<fcvt>> produce (null-terminated) strings of digits
31 representating the <<double>> number <[val]>.
32 <<ecvtf>> and <<fcvtf>> produce the corresponding character
33 representations of <<float>> numbers.
34
35 (The <<stdlib>> functions <<ecvtbuf>> and <<fcvtbuf>> are reentrant
36 versions of <<ecvt>> and <<fcvt>>.)
37
38 The only difference between <<ecvt>> and <<fcvt>> is the
39 interpretation of the second argument (<[chars]> or <[decimals]>).
40 For <<ecvt>>, the second argument <[chars]> specifies the total number
41 of characters to write (which is also the number of significant digits
42 in the formatted string, since these two functions write only digits).
43 For <<fcvt>>, the second argument <[decimals]> specifies the number of
44 characters to write after the decimal point; all digits for the integer
45 part of <[val]> are always included.
46
47 Since <<ecvt>> and <<fcvt>> write only digits in the output string,
48 they record the location of the decimal point in <<*<[decpt]>>>, and
49 the sign of the number in <<*<[sgn]>>>. After formatting a number,
50 <<*<[decpt]>>> contains the number of digits to the left of the
51 decimal point. <<*<[sgn]>>> contains <<0>> if the number is positive,
52 and <<1>> if it is negative.
53
54 RETURNS
55 All four functions return a pointer to the new string containing a
56 character representation of <[val]>.
57
58 PORTABILITY
59 None of these functions are ANSI C.
60
61 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
62 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
63
64 NEWPAGE
65 FUNCTION
66 <<gcvt>>, <<gcvtf>>---format double or float as string
67
68 INDEX
69 gcvt
70 INDEX
71 gcvtf
72
73 SYNOPSIS
74 #include <stdlib.h>
75
76 char *gcvt(double <[val]>, int <[precision]>, char *<[buf]>);
77 char *gcvtf(float <[val]>, int <[precision]>, char *<[buf]>);
78
79 DESCRIPTION
80 <<gcvt>> writes a fully formatted number as a null-terminated
81 string in the buffer <<*<[buf]>>>. <<gcvtf>> produces corresponding
82 character representations of <<float>> numbers.
83
84 <<gcvt>> uses the same rules as the <<printf>> format
85 `<<%.<[precision]>g>>'---only negative values are signed (with
86 `<<->>'), and either exponential or ordinary decimal-fraction format
87 is chosen depending on the number of significant digits (specified by
88 <[precision]>).
89
90 RETURNS
91 The result is a pointer to the formatted representation of <[val]>
92 (the same as the argument <[buf]>).
93
94 PORTABILITY
95 Neither function is ANSI C.
96
97 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
98 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
99 */
100
101 #define _XOPEN_SOURCE
102 #define _XOPEN_SOURCE_EXTENDED
103 #include <stdio.h>
104 #include <stdlib.h>
105 #include "local.h"
106
107 char * ecvtbuf (double, int, int*, int*, char *);
108 char * fcvtbuf (double, int, int*, int*, char *);
109
110 char *
fcvt(double d,int ndigit,int * decpt,int * sign)111 fcvt (double d,
112 int ndigit,
113 int *decpt,
114 int *sign)
115 {
116 return fcvtbuf (d, ndigit, decpt, sign, NULL);
117 }
118
119 char *
fcvtf(float d,int ndigit,int * decpt,int * sign)120 fcvtf (float d,
121 int ndigit,
122 int *decpt,
123 int *sign)
124 {
125 return fcvt ((double) d, ndigit, decpt, sign);
126 }
127
128
129 char *
gcvt(double d,int ndigit,char * buf)130 gcvt (double d,
131 int ndigit,
132 char *buf)
133 {
134 char *tbuf = buf;
135 if (d < 0) {
136 *buf = '-';
137 buf++;
138 ndigit--;
139 }
140 return (_gcvt (d, ndigit, buf, 'g', 0) ? tbuf : 0);
141 }
142
143
144 char *
gcvtf(float d,int ndigit,char * buf)145 gcvtf (float d,
146 int ndigit,
147 char *buf)
148 {
149 double asd = (double) d;
150 return gcvt (asd, ndigit, buf);
151 }
152
153
154 char *
ecvt(double d,int ndigit,int * decpt,int * sign)155 ecvt (double d,
156 int ndigit,
157 int *decpt,
158 int *sign)
159 {
160 return ecvtbuf (d, ndigit, decpt, sign, NULL);
161 }
162
163 char *
ecvtf(float d,int ndigit,int * decpt,int * sign)164 ecvtf (float d,
165 int ndigit,
166 int *decpt,
167 int *sign)
168 {
169 return ecvt ((double) d, ndigit, decpt, sign);
170 }
171
