1 /**
2 * @file lv_string.h
3 *
4 */
5
6 #ifndef LV_STRING_H
7 #define LV_STRING_H
8
9 #ifdef __cplusplus
10 extern "C" {
11 #endif
12
13 /*********************
14 * INCLUDES
15 *********************/
16 #include "../lv_conf_internal.h"
17 #include "../misc/lv_types.h"
18
19 /*********************
20 * DEFINES
21 *********************/
22
23 /**********************
24 * TYPEDEFS
25 **********************/
26
27 /**********************
28 * GLOBAL PROTOTYPES
29 **********************/
30
31 /**
32 * @brief Copies a block of memory from a source address to a destination address.
33 * @param dst Pointer to the destination array where the content is to be copied.
34 * @param src Pointer to the source of data to be copied.
35 * @param len Number of bytes to copy.
36 * @return Pointer to the destination array.
37 * @note The function does not check for any overlapping of the source and destination memory blocks.
38 */
39 void * lv_memcpy(void * dst, const void * src, size_t len);
40
41 /**
42 * @brief Fills a block of memory with a specified value.
43 * @param dst Pointer to the destination array to fill with the specified value.
44 * @param v Value to be set. The value is passed as an int, but the function fills
45 * the block of memory using the unsigned char conversion of this value.
46 * @param len Number of bytes to be set to the value.
47 */
48 void lv_memset(void * dst, uint8_t v, size_t len);
49
50 /**
51 * @brief Move a block of memory from source to destination
52 * @param dst Pointer to the destination array where the content is to be copied.
53 * @param src Pointer to the source of data to be copied.
54 * @param len Number of bytes to copy
55 * @return Pointer to the destination array.
56 */
57 void * lv_memmove(void * dst, const void * src, size_t len);
58
59 /**
60 * @brief This function will compare two memory blocks
61 * @param p1 Pointer to the first memory block
62 * @param p2 Pointer to the second memory block
63 * @param len Number of bytes to compare
64 * @return The difference between the value of the first unmatching byte.
65 */
66 int lv_memcmp(const void * p1, const void * p2, size_t len);
67
68 /**
69 * Same as `memset(dst, 0x00, len)`.
70 * @param dst pointer to the destination buffer
71 * @param len number of byte to set
72 */
lv_memzero(void * dst,size_t len)73 static inline void lv_memzero(void * dst, size_t len)
74 {
75 lv_memset(dst, 0x00, len);
76 }
77
78 /**
79 * @brief Computes the length of the string str up to, but not including the terminating null character.
80 * @param str Pointer to the null-terminated byte string to be examined.
81 * @return The length of the string in bytes.
82 */
83 size_t lv_strlen(const char * str);
84
85 /**
86 * @brief Copies up to dst_size-1 (non-null) characters from src to dst. A null terminator is always added.
87 * @param dst Pointer to the destination array where the content is to be copied.
88 * @param src Pointer to the source of data to be copied.
89 * @param dst_size Maximum number of characters to be copied to dst, including the null character.
90 * @return The length of src. The return value is equivalent to the value returned by lv_strlen(src)
91 */
92 size_t lv_strlcpy(char * dst, const char * src, size_t dst_size);
93
94 /**
95 * @brief Copies up to dest_size characters from the string pointed to by src to the character array pointed to by dst
96 * and fills the remaining length with null bytes.
97 * @param dst Pointer to the destination array where the content is to be copied.
98 * @param src Pointer to the source of data to be copied.
99 * @param dest_size Maximum number of characters to be copied to dst.
100 * @return A pointer to the destination array, which is dst.
101 * @note dst will not be null terminated if dest_size bytes were copied from src before the end of src was reached.
102 */
103 char * lv_strncpy(char * dst, const char * src, size_t dest_size);
104
105 /**
106 * @brief Copies the string pointed to by src, including the terminating null character,
107 * to the character array pointed to by dst.
108 * @param dst Pointer to the destination array where the content is to be copied.
109 * @param src Pointer to the source of data to be copied.
110 * @return A pointer to the destination array, which is dst.
111 */
112 char * lv_strcpy(char * dst, const char * src);
113
114 /**
115 * @brief This function will compare two strings without specified length.
116 * @param s1 pointer to the first string
117 * @param s2 pointer to the second string
118 * @return the difference between the value of the first unmatching character.
119 */
120 int lv_strcmp(const char * s1, const char * s2);
121
122 /**
123 * @brief This function will compare two strings up to the given length.
124 * @param s1 pointer to the first string
125 * @param s2 pointer to the second string
126 * @param len the maximum amount of characters to compare
127 * @return the difference between the value of the first unmatching character.
128 */
129 int lv_strncmp(const char * s1, const char * s2, size_t len);
130
131 /** Returns true if the two strings are equal.
132 * Just a wrapper around strcmp for convenience.
133 * @param s1 pointer to the first string
134 * @param s2 pointer to the second string
135 * @return true: the strings are equal; false: otherwise
136 */
lv_streq(const char * s1,const char * s2)137 static inline bool lv_streq(const char * s1, const char * s2)
138 {
139 return lv_strcmp(s1, s2) == 0;
140 }
141
142 /**
143 * @brief Duplicate a string by allocating a new one and copying the content.
144 * @param src Pointer to the source of data to be copied.
145 * @return A pointer to the new allocated string. NULL if failed.
146 */
147 char * lv_strdup(const char * src);
148
149 /**
150 * @brief Copies the string pointed to by src, including the terminating null character,
151 * to the end of the string pointed to by dst.
152 * @param dst Pointer to the destination string where the content is to be appended.
153 * @param src Pointer to the source of data to be copied.
154 * @return A pointer to the destination string, which is dst.
155 */
156 char * lv_strcat(char * dst, const char * src);
157
158 /**
159 * @brief Copies up to src_len characters from the string pointed to by src
160 * to the end of the string pointed to by dst.
161 * A terminating null character is appended to dst even if no null character
162 * was encountered in src after src_len characters were copied.
163 * @param dst Pointer to the destination string where the content is to be appended.
164 * @param src Pointer to the source of data to be copied.
165 * @param src_len Maximum number of characters from src to be copied to the end of dst.
166 * @return A pointer to the destination string, which is dst.
167 */
168 char * lv_strncat(char * dst, const char * src, size_t src_len);
169
170 /**
171 * @brief Searches for the first occurrence of character c in the string str.
172 * @param str Pointer to the null-terminated byte string to be searched.
173 * @param c The character to be searched for.
174 * @return A pointer to the first occurrence of character c in the string str, or a null pointer if c is not found.
175 */
176 char * lv_strchr(const char * str, int c);
177
178 /**********************
179 * MACROS
180 **********************/
181
182 #ifdef __cplusplus
183 } /*extern "C"*/
184 #endif
185
186 #endif /*LV_STRING_H*/
187
