chatGPT - C programming Linux Windows cross-platform - code review request

_query
    LLM perplexity.ai

Modify code example
  Portable Path Parsing and Validation Code in C
    use thread safe function
      use function pointer
        strtok_s() for Windows
        strtok_r() for linux
allocate INITIAL_BUFFER_SIZE 60 char static path_copy
  declare pointer pfinal_path_copy initialize to path_copy
      when necessary
          dynamically allocate final_path_copy
          pfinal_path_copy = final_path_copy
use single strcpy(pfinal_path_copy, path) function

modify example 
replace 60 by equate

write code example
 parse path in portable way
    linux windows MacOS
        no WSL cygwin

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef _WIN32
#include <io.h>  // For _access() on Windows
#include <windows.h> // For Windows API
#else
#include <unistd.h>  // For access() on Unix-like systems (Linux, macOS)
#include <sys/stat.h>
#endif

// Define a constant for the initial buffer size
#define INITIAL_BUFFER_SIZE 60

// Function to check if a path is valid
int path_validate(const char *path) {
#ifdef _WIN32
    return _access(path, 0) == 0; // 0 means the file exists
#else
    struct stat buffer;
    return (stat(path, &buffer) == 0); // Returns 1 if valid, 0 if invalid
#endif
}

// Type definition for tokenization function pointer
typedef char* (*tokenizer_func)(char*, const char*, char**);

// Function to parse the path into components
void parse_path(const char *path) {
    char path_copy[INITIAL_BUFFER_SIZE]; // Static buffer for initial use
    char *final_path_copy = NULL; // Pointer for dynamic allocation
    char *pfinal_path_copy = path_copy; // Pointer to point to either path_copy or final_path_copy

    // Check if the input path length exceeds INITIAL_BUFFER_SIZE
    if (strlen(path) + 1 > INITIAL_BUFFER_SIZE) {
        final_path_copy = malloc(strlen(path) + 1); // Dynamically allocate memory
        if (final_path_copy == NULL) {
            fprintf(stderr, "Memory allocation failed.\n");
            exit(EXIT_FAILURE);
        }
        pfinal_path_copy = final_path_copy; // Point to dynamically allocated memory
    }

    // Use a single strcpy function to copy the path into the appropriate buffer
    strcpy(pfinal_path_copy, path); // Copy full path into the selected buffer

    // Determine the separator based on the platform and assign the tokenizer function
    const char *separator;
    tokenizer_func tokenizer;
    char *saveptr;

#ifdef _WIN32
    separator = "\\";
    tokenizer = strtok_s; // Use strtok_s for Windows
#else
    separator = "/";
    tokenizer = strtok_r; // Use strtok_r for Linux
#endif

    // Tokenize using the assigned tokenizer function
    char *token = tokenizer(pfinal_path_copy, separator, &saveptr);

    while (token != NULL) {
        printf("Path component: %s\n", token);
        token = tokenizer(NULL, separator, &saveptr); // Continue tokenizing
    }

    free(final_path_copy); // Free dynamically allocated memory after use (if allocated)
}

int main(int argc, char *argv[]) {
    if (argc < 2) {
        fprintf(stderr, "Usage: %s <path>\n", argv[0]);
        return EXIT_FAILURE;
    }

    const char *path = argv[1];

    // Validate the path using the new function name
    if (path_validate(path)) {
        printf("The path '%s' is valid.\n", path);
        printf("Parsing components:\n");
        parse_path(path);
    } else {
        printf("The path '%s' is invalid.\n", path);
    }

    return EXIT_SUCCESS;
}

## Unit test

Was created but not included here

## Performance

The entire exercise took 2:30 hour.
I have not tested the code on Windows or MacOS.
I'd like some feedback on code quality.