dns_service_c/src/lib/file.c

#include "file.h"

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

char *read_file(const char *path) {
  FILE *fp = fopen(path, "rb");
  if (fp == NULL) {
    printf("%s\n", path);
    perror("Error opening file");
    return nullptr;
  }

  fseek(fp, 0, SEEK_END);
  long file_size = ftell(fp);
  rewind(fp);

  char *buffer = (char *)malloc(file_size + 1);
  if (!buffer) {
    perror("Error allocating memory");
    fclose(fp);
    return nullptr;
  }

  size_t bytes_read = fread(buffer, 1, file_size, fp);
  if (bytes_read != file_size) {
    perror("Error reading file");
    free(buffer);
    fclose(fp);
    return nullptr;
  }

  buffer[file_size] = '\0';
  fclose(fp);
  return buffer;
}

char *write_file(const char *path, const char *data) {
    FILE *fp = fopen(path, "w");
    if (fp == NULL) {
        printf("%s\n", path);
      perror("Error opening file");
      return nullptr;
    }
    if (fprintf(fp, "%s", data) < 0) {
        perror("Error write file");
        return nullptr;
    }
    fclose(fp);
    char *ret = strdup(data);
    return ret;
}