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

#define BUFFER_SIZE 256

void create_file(const char *filename) {
    FILE *file = fopen(filename, "w");
    if (file == NULL) {
        printf("Error creating file: %s\n", filename);
        exit(1);
    }
    fclose(file);
}

void write_to_file(const char *filename, const char *content) {
    FILE *file = fopen(filename, "w");
    if (file == NULL) {
        printf("Error opening file: %s\n", filename);
        exit(1);
    }
    fputs(content, file);
    fclose(file);
}

void read_from_file(const char *filename) {
    FILE *file = fopen(filename, "r");
    if (file == NULL) {
        printf("Error opening file: %s\n", filename);
        exit(1);
    }
    char ch;
    while ((ch = fgetc(file)) != EOF) {
        putchar(ch);
    }
    fclose(file);
}

void append_to_file(const char *filename, const char *content) {
    FILE *file = fopen(filename, "a");
    if (file == NULL) {
        printf("Error opening file: %s\n", filename);
        exit(1);
    }
    fputs(content, file);
    fclose(file);
}

void delete_file(const char *filename) {
    if (remove(filename) != 0) {
        printf("Error deleting file: %s\n", filename);
        exit(1);
    }
}

int main() {
    char filename[BUFFER_SIZE];
    char input_buffer[BUFFER_SIZE];

    memset(filename, 0, BUFFER_SIZE);
    memset(input_buffer, 0, BUFFER_SIZE);

    printf("Enter the filename: ");

    // last byte can be non-zero -> leak
    fgets(filename, BUFFER_SIZE, stdin);

    create_file(filename);

    printf("Enter content to write to the file: ");
    fgets(input_buffer, BUFFER_SIZE, stdin);
    write_to_file(filename, input_buffer);

    printf("Content of the file:\n");
    read_from_file(filename);

    printf("\nEnter content to append to the file: ");
    fgets(input_buffer, BUFFER_SIZE, stdin);
    append_to_file(filename, input_buffer);

    printf("\nContent of the file after appending:\n");
    read_from_file(filename);

    delete_file(filename);

    return 0;
}