README.md (1346B)
1 # c-strextra 2 3 A lightweight C library providing additional string utility functions. 4 5 ## Functions 6 7 ### `str_isHex(const char *subject)` 8 Checks if a string contains only hexadecimal characters (0-9, a-f, A-F). 9 Returns `true` if all characters are hex digits, `false` otherwise. 10 11 ### `strnstr(const char *haystack, const char *needle, size_t len)` 12 Finds the first occurrence of a substring in a string with a length limit. 13 Similar to `strstr()` but only searches the first `len` characters. 14 Returns a pointer to the found substring or `NULL` if not found. 15 16 ### `strtoupper(char *str)` 17 Converts all characters in a string to uppercase. 18 Modifies the input string in-place and returns a pointer to it. 19 20 ### `strcasecmp(const char *a, const char *b)` 21 Case-insensitive string comparison. 22 On Windows (where this function may not be available), provides a custom implementation. 23 Returns 0 if strings are equal (case-insensitive), negative if `a < b`, positive if `a > b`. 24 25 ## Usage 26 27 Include the main header file: 28 29 ```c 30 #include "str_extra.h" 31 ``` 32 33 Or include individual headers for specific functions. 34 35 ## Platform Support 36 37 - Works on POSIX systems (Linux, macOS) and Windows 38 - `strcasecmp` uses system implementation where available, provides fallback for Windows 39 - Standard C library dependencies: `<ctype.h>`, `<string.h>`, `<stdlib.h>`, `<stdbool.h>`