c - 为什么会发生这种内存泄漏？

Question

我已将内存泄漏隔离到这些行:

char* word_ptr;
while(read_word(fp, word)) {
    word_ptr = strdup(to_lower_case(word));
    // other stuff happens, loop closes properly, etc.

因为我没有 malloc word_ptr，所以我不需要释放它。如果你需要小写函数，就在这里:

char* to_lower_case(char *string) {
    for (int i = 0; i < strlen(string); i++) {
        string[i] = tolower(string[i]);
    }

    return string;
}

Answer 1

Since I don't malloc word_ptr ...

但是strdup()用malloc()分配内存，所以都是一样的。

来自 man 3 strdup:

Memory for the new string is obtained with malloc(3), and can be freed with free(3).