1 /*
2??*??linux/lib/string.c
3??*
4??*??Copyright (C) 1991, 1992??Linus Torvalds
5??*/
6
7 /*
8??* stupid library routines.. The optimized versions should generally be found
9??* as inline code in <asm-xx/string.h>
10??*
11??* These are buggy as well..
12??*/
13??
14 #include <linux/types.h>
15
16 char * ___strtok = NULL;
17
18 char * strcpy(char * dest,const char *src)
19 {
20?????????char *tmp = dest;
21
22?????????while ((*dest++ = *src++) != '\0')
23?????????????????/* nothing */;
24?????????return tmp;
25 }
26
27 char * strncpy(char * dest,const char *src,size_t count)
28 {
29?????????char *tmp = dest;
30
31?????????while (count-- && (*dest++ = *src++) != '\0')
32?????????????????/* nothing */;
33
34?????????return tmp;
35 }
36
37 char * strcat(char * dest, const char * src)
38 {
39?????????char *tmp = dest;
40
41?????????while (*dest)
42?????????????????dest++;
43?????????while ((*dest++ = *src++) != '\0')
44?????????????????;
45
46?????????return tmp;
47 }
48
49 char * strncat(char *dest, const char *src, size_t count)
50 {
51?????????char *tmp = dest;
52
53?????????if (count) {
54?????????????????while (*dest)
55?????????????????????????dest++;
56?????????????????while ((*dest++ = *src++)) {
57?????????????????????????if (--count == 0)
58?????????????????????????????????break;
59?????????????????}
60?????????}
61
62?????????return tmp;
63 }
64
65 int strcmp(const char * cs,const char * ct)
66 {
67?????????register signed char __res;
68
69?????????while (1) {
70?????????????????if ((__res = *cs - *ct++) != 0 || !*cs++)
71?????????????????????????break;
72?????????}
73
74?????????return __res;
75 }
76
77 int strncmp(const char * cs,const char * ct,size_t count)
78 {
79?????????register signed char __res = 0;
80
81?????????while (count) {
82?????????????????if ((__res = *cs - *ct++) != 0 || !*cs++)
83?????????????????????????break;
84?????????????????count--;
85?????????}
86
87?????????return __res;
88 }
89
90 char * strchr(const char * s,char c)
91 {
92?????????for(; *s != c; ++s)
93?????????????????if (*s == '\0')
94?????????????????????????return NULL;
95?????????return (char *) s;
96 }
97
98 size_t strlen(const char * s)
99 {
100?????????const char *sc;
101
102?????????for (sc = s; *sc != '\0'; ++sc)
103?????????????????/* nothing */;
104?????????return sc - s;
105 }
106
107 size_t strnlen(const char * s, size_t count)
108 {
109?????????const char *sc;
110
111?????????for (sc = s; *sc != '\0' && count--; ++sc)
112?????????????????/* nothing */;
113?????????return sc - s;
114 }
115
116 size_t strspn(const char *s, const char *accept)
117 {
118?????????const char *p;
119?????????const char *a;
120?????????size_t count = 0;
121
122?????????for (p = s; *p != '\0'; ++p) {
123?????????????????for (a = accept; *a != '\0'; ++a) {
124?????????????????????????if (*p == *a)
125?????????????????????????????????break;
126?????????????????}
127?????????????????if (*a == '\0')
128?????????????????????????return count;
129?????????????????++count;
130?????????}
131
132?????????return count;
133 }
134
135 char * strpbrk(const char * cs,const char * ct)
136 {
137?????????const char *sc1,*sc2;
138
139?????????for( sc1 = cs; *sc1 != '\0'; ++sc1) {
140?????????????????for( sc2 = ct; *sc2 != '\0'; ++sc2) {
141?????????????????????????if (*sc1 == *sc2)
142?????????????????????????????????return (char *) sc1;
143?????????????????}
144?????????}
145?????????return NULL;
146 }
147
148 char * strtok(char * s,const char * ct)
149 {
150?????????char *sbegin, *send;
151
152?????????sbegin??= s ? s : ___strtok;
153?????????if (!sbegin) {
154?????????????????return NULL;
155?????????}
156?????????sbegin += strspn(sbegin,ct);
157?????????if (*sbegin == '\0') {
158?????????????????___strtok = NULL;
159?????????????????return( NULL );
160?????????}
161?????????send = strpbrk( sbegin, ct);
162?????????if (send && *send != '\0')
163?????????????????*send++ = '\0';
164?????????___strtok = send;
165?????????return (sbegin);
166 }
167
168 void * memset(void * s,char c,size_t count)
169 {
170?????????char *xs = (char *) s;
171
172?????????while (count--)
173?????????????????*xs++ = c;
174
175?????????return s;
176 }
177
178 char * bcopy(const char * src, char * dest, int count)
179 {
180?????????char *tmp = dest;
181
182?????????while (count--)
183?????????????????*tmp++ = *src++;
184
185?????????return dest;
186 }
187
188 void * memcpy(void * dest,const void *src,size_t count)
189 {
190?????????char *tmp = (char *) dest, *s = (char *) src;
191
192?????????while (count--)
193?????????????????*tmp++ = *s++;
194
195?????????return dest;
196 }
197
198 void * memmove(void * dest,const void *src,size_t count)
199 {
200?????????char *tmp, *s;
201
202?????????if (dest <= src) {
203?????????????????tmp = (char *) dest;
204?????????????????s = (char *) src;
205?????????????????while (count--)
206?????????????????????????*tmp++ = *s++;
207?????????????????}
208?????????else {
209?????????????????tmp = (char *) dest + count;
210?????????????????s = (char *) src + count;
211?????????????????while (count--)
212?????????????????????????*--tmp = *--s;
213?????????????????}
214
215?????????return dest;
216 }
217
218 int memcmp(const void * cs,const void * ct,size_t count)
219 {
220?????????const unsigned char *su1, *su2;
221?????????signed char res = 0;
222
223?????????for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
224?????????????????if ((res = *su1 - *su2) != 0)
225?????????????????????????break;
226?????????return res;
227 }
228
229 /*
230??* find the first occurrence of byte 'c', or 1 past the area if none
231??*/
232 void * memscan(void * addr, unsigned char c, size_t size)
233 {
234?????????unsigned char * p = (unsigned char *) addr;
235
236?????????while (size) {
237?????????????????if (*p == c)
238?????????????????????????return (void *) p;
239?????????????????p++;
240?????????????????size--;
241?????????}
242?????????return (void *) p;
243 }