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5f83300c LM |
1 | /* |
2 | File name : fprintf.c | |
3 | Date of creation : 05/12/2022 | |
4 | Version : 1.0 | |
5 | Copyright : Soft'n'design | |
6 | Author : Laurent Mazet <mazet@softndesign.org> | |
7 | ||
8 | Description : This file contains embedded printf | |
9 | ||
10 | History : | |
11 | - initial version | |
12 | */ | |
13 | ||
14 | #include <stdarg.h> | |
15 | #include <stddef.h> | |
16 | #include <stdio.h> | |
17 | ||
b40343bc | 18 | inline unsigned int nextpow (unsigned int x, int base) { |
5f83300c LM |
19 | unsigned int n = 0; |
20 | while (x) { | |
21 | n++; | |
b40343bc | 22 | x = x / base; |
5f83300c LM |
23 | } |
24 | return (n == 0) ? 1 : n; | |
25 | } | |
26 | ||
27 | /* simple fprintf function */ | |
28 | ||
5e0c5bc8 | 29 | size_t myfprintf (FILE *fid, const char *fmt, ...) |
5f83300c LM |
30 | { |
31 | char buffer[1024 + 1] = { 0 }; | |
32 | char *str = buffer; | |
33 | ||
34 | va_list ap; | |
35 | va_start (ap, fmt); | |
36 | while (*fmt) { | |
37 | char *s; | |
38 | int d = 0; | |
39 | unsigned int u; | |
5f83300c LM |
40 | char c = *fmt++; |
41 | ||
42 | /* copy standard char */ | |
43 | if (c != '%') { | |
44 | *str++ = c; | |
45 | } else { | |
46 | int t = 0; | |
b40343bc LM |
47 | char w = '0'; |
48 | size_t i, sz = 0; | |
49 | void *p = NULL; | |
50 | ||
51 | /* stamp */ | |
52 | if ((*fmt == ' ') || (*fmt == '0')) { | |
53 | w = *fmt++; | |
54 | } | |
55 | ||
56 | /* size */ | |
57 | if ((*fmt >= '1') && (*fmt <= '9')) { | |
58 | sz = *fmt++ - '0'; | |
59 | } | |
5f83300c LM |
60 | |
61 | /* process format char */ | |
62 | switch (*fmt++) { | |
63 | case 'c': /* char */ | |
64 | c = (char) va_arg (ap, int); | |
65 | *str++ = c; | |
66 | break; | |
67 | case 'd': /* int */ | |
68 | d = va_arg (ap, int); | |
69 | if (d < 0) { | |
70 | *str++ = '-'; | |
71 | d = -d; | |
72 | } | |
73 | t = 1; | |
74 | /* fall through */ | |
75 | case 'u': /* unsigned int */ | |
76 | u = (t) ? (unsigned int)d : va_arg (ap, unsigned int); | |
b40343bc | 77 | for (i = nextpow (u, 10), s = str; i > 0; i--, s++) { |
5f83300c LM |
78 | str[i - 1] = '0' + (u % 10); |
79 | u /= 10; | |
80 | } | |
81 | str = s; | |
82 | break; | |
83 | case 'p': /* pointer */ | |
5f83300c LM |
84 | *str++ = '0'; |
85 | *str++ = 'x'; | |
b40343bc LM |
86 | w = '0'; |
87 | sz = sizeof (void *) * 2; | |
88 | p = va_arg (ap, void *); | |
89 | /* fall through */ | |
90 | case 'x': /* integer hexa */ | |
91 | if (!p) { | |
92 | u = va_arg (ap, unsigned int); | |
93 | p = (void *)u; | |
94 | if (sz == 0) { | |
95 | sz = nextpow (u, 16); | |
96 | } | |
97 | } | |
98 | for (i = sz, t = 1; i > 0; i--) { | |
5f83300c | 99 | char x = (char)(((uintptr_t)p >> (i * 4 - 4)) & 0xf); |
b40343bc LM |
100 | if ((t == 1) && (x == 0)) { |
101 | *str++ = w; | |
102 | } else { | |
103 | *str++ = (x > 9) ? 'a' + x - 10 : '0' + x; | |
104 | t = 0; | |
105 | } | |
5f83300c LM |
106 | } |
107 | break; | |
108 | case 's': /* string */ | |
109 | s = va_arg (ap, char *); | |
110 | while (s && *s) | |
111 | *str++ = *s++; | |
112 | break; | |
113 | default: | |
114 | *str++ = '?'; | |
115 | } | |
116 | } | |
117 | } | |
118 | va_end (ap); | |
119 | ||
120 | /* output string */ | |
121 | size_t n = str - buffer; | |
122 | if (n < sizeof (buffer) - 1) { | |
123 | fwrite (buffer, n, 1, fid); | |
124 | return n; | |
125 | } | |
126 | return 0; | |
127 | } | |
128 | ||
b40343bc | 129 | /* vim: set ts=4 sw=4 et: */ |