forked from M-Labs/nac3
core/irrt: add cstr_utils
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@ -21,4 +21,84 @@ bool arrays_match(int len, T* as, T* bs) {
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}
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return true;
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}
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namespace cstr_utils {
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/**
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* @brief Return true if `str` is empty.
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*/
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bool is_empty(const char* str) { return str[0] == '\0'; }
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/**
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* @brief Implementation of `strcmp()`
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*/
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int8_t compare(const char* a, const char* b) {
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uint32_t i = 0;
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while (true) {
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if (a[i] < b[i]) {
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return -1;
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} else if (a[i] > b[i]) {
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return 1;
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} else {
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if (a[i] == '\0') {
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return 0;
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} else {
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i++;
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}
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}
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}
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}
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/**
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* @brief Return true two strings have the same content.
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*/
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int8_t equal(const char* a, const char* b) { return compare(a, b) == 0; }
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/**
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* @brief Implementation of `strlen()`.
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*/
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uint32_t length(const char* str) {
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uint32_t length = 0;
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while (*str != '\0') {
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length++;
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str++;
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}
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return length;
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}
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/**
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* @brief Copy a null-terminated string to a buffer with limited size and guaranteed null-termination.
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*
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* `dst_max_size` must be greater than 0, otherwise this function has undefined behavior.
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*
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* This function attempts to copy everything from `src` from `dst`, and *always* null-terminates `dst`.
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*
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* If the size of `dst` is too small, the final byte (`dst[dst_max_size - 1]`) of `dst` will be set to
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* the null terminator.
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*
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* @param src String to copy from.
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* @param dst Buffer to copy string to.
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* @param dst_max_size
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* Number of bytes of this buffer, including the space needed for the null terminator.
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* Must be greater than 0.
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* @return If `dst` is too small to contain everything in `src`.
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*/
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bool copy(const char* src, char* dst, uint32_t dst_max_size) {
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for (uint32_t i = 0; i < dst_max_size; i++) {
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bool is_last = i + 1 == dst_max_size;
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if (is_last && src[i] != '\0') {
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dst[i] = '\0';
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return false;
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}
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if (src[i] == '\0') {
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dst[i] = '\0';
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return true;
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}
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dst[i] = src[i];
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}
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__builtin_unreachable();
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}
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} // namespace cstr_utils
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} // namespace
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