C program made by ChatGPT to update Minecraft iOS materials

main.c

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

#define HEX_PATTERN1 "\x4D\x65\x74\x61\x6C\x00\x0B"
#define REPLACEMENT1 "\x4D\x65\x74\x61\x6C\x00\x0A"

#define HEX_PATTERN2 "\x4D\x65\x74\x61\x6C\x01\x0B"
#define REPLACEMENT2 "\x4D\x65\x74\x61\x6C\x01\x0A"

void process_file(const char *filename) {
    FILE *file = fopen(filename, "r+b");
    if (file == NULL) {
        perror("Error opening file");
        return;
    }

    // Get the file size
    fseek(file, 0, SEEK_END);
    long file_size = ftell(file);
    fseek(file, 0, SEEK_SET);

    // Allocate buffer to read file contents
    unsigned char *buffer = (unsigned char *)malloc(file_size);
    if (buffer == NULL) {
        perror("Memory allocation failed");
        fclose(file);
        return;
    }

    // Read the entire file into the buffer
    fread(buffer, 1, file_size, file);

    // Look for the patterns and replace them
    for (long i = 0; i < file_size - 7; i++) {
        if (memcmp(&buffer[i], HEX_PATTERN1, 7) == 0) {
            memcpy(&buffer[i], REPLACEMENT1, 7);
        } else if (memcmp(&buffer[i], HEX_PATTERN2, 7) == 0) {
            memcpy(&buffer[i], REPLACEMENT2, 7);
        }
    }

    // Move file pointer back to the beginning to write the modified data
    fseek(file, 0, SEEK_SET);
    fwrite(buffer, 1, file_size, file);

    // Clean up
    free(buffer);
    fclose(file);
}

int main() {
    DIR *dir = opendir(".");
    if (dir == NULL) {
        perror("Unable to open directory");
        return 1;
    }

    struct dirent *entry;
    while ((entry = readdir(dir)) != NULL) {
        // Check if the file ends with ".material.bin"
        if (strstr(entry->d_name, ".material.bin") != NULL) {
            printf("Processing file: %s\n", entry->d_name);
            process_file(entry->d_name);
        }
    }

    closedir(dir);
    return 0;
}