1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) Paul Mackerras 1997.
4 */
5 #include <linux/string.h>
6 #include <linux/stdarg.h>
7
8 size_t strnlen(const char * s, size_t count)
9 {
10 const char *sc;
11
12 for (sc = s; count-- && *sc != '\0'; ++sc)
13 /* nothing */;
14 return sc - s;
15 }
16
17 # define do_div(n, base) ({ \
18 unsigned int __base = (base); \
19 unsigned int __rem; \
20 __rem = ((unsigned long long)(n)) % __base; \
21 (n) = ((unsigned long long)(n)) / __base; \
22 __rem; \
23 })
24
25
26 static int skip_atoi(const char **s)
27 {
28 int i, c;
29
30 for (i = 0; '' <= (c = **s) && c <= '9'; ++*s)
31 i = i*10 + c - '';
32 return i;
33 }
34
35 #define ZEROPAD 1 /* pad with zero */
36 #define SIGN 2 /* unsigned/signed long */
37 #define PLUS 4 /* show plus */
38 #define SPACE 8 /* space if plus */
39 #define LEFT 16 /* left justified */
40 #define SPECIAL 32 /* 0x */
41 #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
42
43 static char * number(char * str, unsigned long long num, int base, int size, int precision, int type)
44 {
45 char c, sign, tmp[66];
46 const char *digits = "0123456789abcdefghijklmnopqrstuvwxyz";
47 int i;
48
49 if (type & LARGE)
50 digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
51 if (type & LEFT)
52 type &= ~ZEROPAD;
53 if (base < 2 || base > 36)
54 return 0;
55 c = (type & ZEROPAD) ? '' : ' ';
56 sign = 0;
57 if (type & SIGN) {
58 if ((signed long long)num < 0) {
59 sign = '-';
60 num = - (signed long long)num;
61 size--;
62 } else if (type & PLUS) {
63 sign = '+';
64 size--;
65 } else if (type & SPACE) {
66 sign = ' ';
67 size--;
68 }
69 }
70 if (type & SPECIAL) {
71 if (base == 16)
72 size -= 2;
73 else if (base == 8)
74 size--;
75 }
76 i = 0;
77 if (num == 0)
78 tmp[i++]='';
79 else while (num != 0) {
80 tmp[i++] = digits[do_div(num, base)];
81 }
82 if (i > precision)
83 precision = i;
84 size -= precision;
85 if (!(type&(ZEROPAD+LEFT)))
86 while (size-- > 0)
87 *str++ = ' ';
88 if (sign)
89 *str++ = sign;
90 if (type & SPECIAL) {
91 if (base==8)
92 *str++ = '';
93 else if (base == 16) {
94 *str++ = '';
95 *str++ = digits[33];
96 }
97 }
98 if (!(type & LEFT))
99 while (size-- > 0)
100 *str++ = c;
101 while (i < precision--)
102 *str++ = '';
103 while (i-- > 0)
104 *str++ = tmp[i];
105 while (size-- > 0)
106 *str++ = ' ';
107 return str;
108 }
109
110 int vsprintf(char *buf, const char *fmt, va_list args)
111 {
112 int len;
113 unsigned long long num;
114 int i, base;
115 char * str;
116 const char *s;
117
118 int flags; /* flags to number() */
119
120 int field_width; /* width of output field */
121 int precision; /* min. # of digits for integers; max
122 number of chars for from string */
123 int qualifier; /* 'h', 'l', or 'L' for integer fields */
124 /* 'z' support added 23/7/1999 S.H. */
125 /* 'z' changed to 'Z' --davidm 1/25/99 */
126
127
128 for (str = buf ; *fmt ; ++fmt) {
129 if (*fmt != '%') {
130 *str++ = *fmt;
131 continue;
132 }
133
134 /* process flags */
135 flags = 0;
136 repeat:
137 ++fmt; /* this also skips first '%' */
138 switch (*fmt) {
139 case '-': flags |= LEFT; goto repeat;
140 case '+': flags |= PLUS; goto repeat;
141 case ' ': flags |= SPACE; goto repeat;
142 case '#': flags |= SPECIAL; goto repeat;
143 case '': flags |= ZEROPAD; goto repeat;
144 }
145
146 /* get field width */
147 field_width = -1;
148 if ('' <= *fmt && *fmt <= '9')
149 field_width = skip_atoi(&fmt);
150 else if (*fmt == '*') {
151 ++fmt;
152 /* it's the next argument */
153 field_width = va_arg(args, int);
154 if (field_width < 0) {
155 field_width = -field_width;
156 flags |= LEFT;
157 }
158 }
159
160 /* get the precision */
161 precision = -1;
162 if (*fmt == '.') {
163 ++fmt;
164 if ('' <= *fmt && *fmt <= '9')
165 precision = skip_atoi(&fmt);
166 else if (*fmt == '*') {
167 ++fmt;
168 /* it's the next argument */
169 precision = va_arg(args, int);
170 }
171 if (precision < 0)
172 precision = 0;
173 }
174
175 /* get the conversion qualifier */
176 qualifier = -1;
177 if (*fmt == 'l' && *(fmt + 1) == 'l') {
178 qualifier = 'q';
179 fmt += 2;
180 } else if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L'
181 || *fmt == 'Z') {
182 qualifier = *fmt;
183 ++fmt;
184 }
185
186 /* default base */
187 base = 10;
188
189 switch (*fmt) {
190 case 'c':
191 if (!(flags & LEFT))
192 while (--field_width > 0)
193 *str++ = ' ';
194 *str++ = (unsigned char) va_arg(args, int);
195 while (--field_width > 0)
196 *str++ = ' ';
197 continue;
198
199 case 's':
200 s = va_arg(args, char *);
201 if (!s)
202 s = "<NULL>";
203
204 len = strnlen(s, precision);
205
206 if (!(flags & LEFT))
207 while (len < field_width--)
208 *str++ = ' ';
209 for (i = 0; i < len; ++i)
210 *str++ = *s++;
211 while (len < field_width--)
212 *str++ = ' ';
213 continue;
214
215 case 'p':
216 if (field_width == -1) {
217 field_width = 2*sizeof(void *);
218 flags |= ZEROPAD;
219 }
220 str = number(str,
221 (unsigned long) va_arg(args, void *), 16,
222 field_width, precision, flags);
223 continue;
224
225
226 case 'n':
227 if (qualifier == 'l') {
228 long * ip = va_arg(args, long *);
229 *ip = (str - buf);
230 } else if (qualifier == 'Z') {
231 size_t * ip = va_arg(args, size_t *);
232 *ip = (str - buf);
233 } else {
234 int * ip = va_arg(args, int *);
235 *ip = (str - buf);
236 }
237 continue;
238
239 case '%':
240 *str++ = '%';
241 continue;
242
243 /* integer number formats - set up the flags and "break" */
244 case 'o':
245 base = 8;
246 break;
247
248 case 'X':
249 flags |= LARGE;
250 case 'x':
251 base = 16;
252 break;
253
254 case 'd':
255 case 'i':
256 flags |= SIGN;
257 case 'u':
258 break;
259
260 default:
261 *str++ = '%';
262 if (*fmt)
263 *str++ = *fmt;
264 else
265 --fmt;
266 continue;
267 }
268 if (qualifier == 'l') {
269 num = va_arg(args, unsigned long);
270 if (flags & SIGN)
271 num = (signed long) num;
272 } else if (qualifier == 'q') {
273 num = va_arg(args, unsigned long long);
274 if (flags & SIGN)
275 num = (signed long long) num;
276 } else if (qualifier == 'Z') {
277 num = va_arg(args, size_t);
278 } else if (qualifier == 'h') {
279 num = (unsigned short) va_arg(args, int);
280 if (flags & SIGN)
281 num = (signed short) num;
282 } else {
283 num = va_arg(args, unsigned int);
284 if (flags & SIGN)
285 num = (signed int) num;
286 }
287 str = number(str, num, base, field_width, precision, flags);
288 }
289 *str = '\0';
290 return str-buf;
291 }
292
293 int sprintf(char * buf, const char *fmt, ...)
294 {
295 va_list args;
296 int i;
297
298 va_start(args, fmt);
299 i = vsprintf(buf, fmt, args);
300 va_end(args);
301 return i;
302 }
303
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